Don't get caught in a Sisyphean struggle

LOD and Revit Families: How to Avoid Running a Fool’s Errand

As a Revit user or BIM Manager, you’ve probably had people ask you about “LOD” or “Level of Development”. When it comes to Revit content, this usually translates to asking which LOD your families are designed to meet – 100, 200, 300? You might also be asked about creating different LOD versions of the same families, in order to swap them in and out of models for different stages of deliverables.

These are questions we’ve encountered too many times over the years, and in our view they reflect a misunderstanding both of LOD and of how Revit families are designed to work. This post is an attempt to synthesize our perspective on how LOD applies to Revit families based on our decade-plus of experience creating content and working with consultants, architects and manufacturers. It’s our answer to what works, what doesn’t and how to think about LOD in order to get the most out of Revit content for teams working in projects. But before we get to our answer, let’s back up and clarify what LOD is exactly.

LOD Concept Origins

LOD is a concept first created by the AIA back in 2008 to define the amount of information contained in a BIM element. The AIA established five different “levels of development” that a model element could achieve – 100, 200, 300, 400 and 500 – later adding a sixth level at 350. For example, LOD 100 would only offer generic representation of an object without detail on size or location, while LOD 300 would include specifics on size, shape, orientation, location and quantity.

This core concept was then taken up by the BIMForum, who defined exactly what each level should cover for different types of building components and systems. This took the form of a Level of Development (LOD) Specification first published in 2013. As of this July, the BIMForum has just published an updated 2018 Draft Specification currently available for public comment.

At a high level, LOD makes perfect sense when it comes to looking at how a BIM model will progress over the course of design, construction and maintenance. As more and more of a building’s components and systems are fully specified and made operational, more and more accurate information about them can be incorporated into the model. The architect can say, “A door that looks like this should go right about here,” while later on the contractor can say, “This door model XYZ by manufacturer ABC has been purchased for such-and-such amount and installed in this exact location.”

Problems with LOD and Revit

1. Forbidding “higher LOD” elements in your models.

When it comes to Revit families, the adoption of LOD standards leads to two common misconceptions. The first is the belief that families should not have more detail than required for whatever LOD a firm needs to fulfill. For example, if a firm is responsible for delivering a model at LOD 200, they might have a policy that forbids using any manufacturer-specific Revit families in their model, since LOD 200 is defined as a generic representation of an object, system or assembly.

The thought process behind this lowest-common-denominator approach is something like the following: “If we put in a manufacturer-specific family, then we’ll be liable for having specified that object, and we don’t want to be responsible for that!” What this attitude misses is the fact that just because a model element has more detail does not mean that it meets a higher LOD.

In fact, BIMForum takes pains to make it clear that LOD is not equivalent to “Level of Detail”. In their 2017 Specification, they include the following explanation in a section titled “Level of Development vs. Level of Detail” (section 2.2, italics are theirs):

LOD is sometimes interpreted as Level of Detail rather than Level of Development. This Specification uses the concept of Level of Development. There are important differences.

Level of Detail is essentially how much detail is included in the model element. Level of Development is the degree to which the element’s geometry and attached information has been thought through – the degree to which project team members may rely on the information when using the model.

In essence, Level of Detail can be thought of as input to the element, while Level of Development is reliable output.

What this means is that the LOD of a model element is not automatically determined by the degree of detail or amount of information that it includes. Rather its LOD depends on the amount of detail and information that “project team members may rely on” when examining that element. If you deliver a Revit model containing 100% manufacturer-specific elements, but you clearly state in your handover that the model elements are all LOD 200, then they are all LOD 200 – they are to be relied upon for generic representations only and not for specification.

Trying to forbid higher LOD content also puts the responsibility for compliance on the wrong people. Architects, engineers and modelers shouldn’t be burdened with ensuring no piece of content qualifies for a higher LOD. Aside from a plain template or brand new project, any Revit model will end up having manufacturer-specific content. It just might not be visible right away.

Rather than pursuing the lost cause of prohibiting higher-LOD content, you will save time, improve the saleability of your work, reduce mistakes, and increase the likelihood that your design choices and preferred products will be incorporated in the final result.

So from the standpoint of a firm’s liability for delivering models at a certain LOD, it’s not necessary to prohibit more detailed information from entering the model. What’s necessary is to have a good disclaimer or documentation that makes it clear what LOD the model elements should be treated as. Meanwhile, rather than pursuing the lost cause of prohibiting higher-LOD content, you will end up saving time, improving the saleability of your work, reducing mistakes (e.g. no more tiny generic box for a fan that can’t possibly be manufactured), and increasing the likelihood that your design choices and preferred products will be incorporated in the final result.

2. Creating families to meet a specific LOD.

The other common misconception that people make when trying to apply LOD to Revit content is to insist that families be created to one particular LOD. This misguided approach usually follows from the first one described above – if a firm generally delivers at LOD 200, then what better way to ensure no “higher LOD” families make it in than to create all families at LOD 200!

As we noted above, this approach is rooted in the misconception that a family’s LOD is determined by the amount of detail it contains. Instead, we clarified that it’s determined by the amount of information that project team members should rely on from that family.

LOD 300, for example, requires that a model element have a specific quantity, location and orientation.

It’s also worth pointing out that LOD involves aspects that simply are not inherent to Revit families themselves, but rather are driven by the model context in which families are used. This includes things like quantities, location and orientation. LOD 300, for example, requires that a model element have a specific quantity, location and orientation. But whether those attributes are specific or not depends entirely on how the family has been placed in a project. The family itself, outside of the project context, will never have any quantity, location or orientation. So strictly speaking, it’s not even possible to create a Revit family to LOD 300.

In addition, trying to create Revit families to a particular LOD means overlooking two of Revit’s key features for families, namely Levels of Detail and Visibility Graphics. These are features that let you control exactly which family geometry displays in different views within Revit. It means you can have a family that displays a symbol (LOD 100) in coarse plan view, a generic-looking unit in 3D medium view (LOD 200), and manufacturer-specific geometry in 3D fine (LOD 300).

Toshiba floor model Revit family in 3D Fine
Toshiba floor model Revit family in 3D Medium
Toshiba floor model Revit family in 3D Coarse
Andekan-made Toshiba Revit family in Fine, Medium and Coarse 3D views

You can also use family types and parameters to display or hide different geometry and metadata for different instances of a family within a project. So you could have a piece of mechanical equipment with an instance parameter for “Hanging Rods” that can be toggled on when you want to show that detail of how the unit needs to be installed (LOD 400). Or you could have a family with a generic type that doesn’t include any manufacturer information in it, and then specific types that include manufacturer name, model number, etc. (not that we would recommend that particular approach).

In short, Revit is designed so that your families can display with different degrees of detail as project needs dictate. Trying to model your families to just one LOD would mean throwing away that flexibility and losing out on one of Revit’s most powerful and useful features. If we accept the conclusions above that LOD depends not just on what information the element contains, but also on what LOD you claim the element meets and on how the element has been incorporated into the model, then why not create your families to allow for the maximum possible range of LOD?

Chargepoint Revit family in 2D Fine
Chargepoint Revit family in 2D Medium
Chargepoint Revit family in 2D Coarse
Andekan-made Chargepoint Revit family in Fine, Medium and Coarse 2D views

Conclusion: Make Revit content as useful as possible.

Our simple advice to firms building new Revit families is to make your content as useful as possible based on what you know and the resources you have available. You have three levels of detail available in Revit, so make use of them by showing a volumetric mass in coarse, a generic representation in medium, and a more specific representation in fine. Even if you never specify products in your deliverables, you still ought to base your families on comparable manufacturer products so that they look and behave as realistically as possible within a project. If you know that the object should show a symbol in plan views, go ahead and add one as a nested annotation and display it in plan view only. If you have a preferred manufacturer for a certain product, go ahead and list it in the family’s Identity Data parameters. If you’re aware of a certain installation detail that ought to be taken into account for coordination, make sure it’s included and can easily be displayed when needed.

Sure this approach takes more planning and effort than just building a library of generic blocks to meet LOD 200, but the payoff in project quality and usability will be more than worth it for your team and project partners. You also save yourself the headache of scrambling for substitutes and new versions when you run into a situation that requires a different LOD output. Your library will stand the test of time, and the next time someone asks that dreaded question of which LOD your families meet, you’ll have the perfect answer: whichever one you need.

Weighing the tradeoffs of shared parameter strategies

Shared Parameter Tradeoffs: Short-Term Gains vs Long-Term Pains

In the past months, we’ve been working closely with consulting engineering firms to produce families that work with their shared parameters. The process has brought to the surface some issues that we think deserve closer attention for the way that they can impact the long-term utility of a firm’s shared parameters.

The first issue concerns itself with the units assigned to shared parameters that relate to MEP systems. In our recent experience, we’ve found that many of the parameters associated with duct or pipe connectors get set with generic disciplines and units. For example, a parameter for “Water Diameter” pipe connection would be set to a discipline of “Common – Length” as opposed to “Piping – Pipe Size”. Or “Water Pressure Drop” would be created as “Common – Number” instead of “Piping – Pressure”.

When raising this issue to clients, they will counter that having these parameters in Common units doesn’t have any adverse effect on Revit system calculations and that it actually makes their scheduling workflow easier. There’s some truth to this argument, but also some potential drawbacks, so let’s take a closer look.

When I place a pipe connector, for example, and select the loss method as Specific Loss, I then need to path family parameters for flow rate and pressure drop to the connector (see image below). In order to path family parameters to the connector parameters, the family parameter values must be in the correct discipline, otherwise Revit will not path them. The family parameter for Pressure Drop, for example, must be in discipline “Pressure”. So, if I set my shared parameter for Water Pressure Drop to be in units of Common – Number, then I’m going to have a problem if I want to have that parameter pull its value from a piping system connector.

Connector parameter dialog with family parameter association highlighted

Electrical connectors can have even more values that need correct parameter pathing, especially a power connector that will have Number of Poles, Voltage, Current, etc. All of these need to be in the correct units. So these need to be identified in the firm’s shared parameter file and updated if incorrect. This is something that we’ve talked about for years, but it still gets overlooked more often than it should.

On the other hand, the particular discipline used for assigning units has a much more subtle impact. For example, let’s consider a shared parameter that will control a pipe diameter. In this case, Revit allows more than one discipline-unit to be pathed into the radius/diameter of the connector.

In the image below, I created a simple test family. Within the family there is a diameter parameter for each discipline-unit (pipe size, duct size, pipe dimension, common length etc…). When I start to path a parameter to the connector’s diameter, you can see in the image that the parameter type is simply “Length” and that Revit allows you to path ANY length parameter to the pipe connector, even a nonsensical one like duct size.

Associating Length Parameters to a Connector Length

This raises the question of why we should bother to specify the shared parameter for a connector length as anything other than “Common – Length”. I believe the answer has to do with units and having the control to use different units for your piping, ducting and general lengths/dimensions. By assigning different discipline-units to different shared parameters for length, a project can have its piping shown in millimeters, duct in inches, and so on.

So Revit gives the user the ability to exercise more fine-tuned control with how units are displayed on a drawing (tagged). But if we just use “common – length” for any shared parameter that can take it, we lose that flexibility and open ourselves up to the possibility of inconsistencies between drawings and schedules, or even inconsistencies on the MEP layouts depending on which elements are tagged in the drawing.

In addition, for pipe systems in particular, there is an intrinsic parameter called “Size” which is set as a Piping – Pipe Size parameter (see image below). I can change the fitting connectors to use Common – Length or even Pipe Size – Pipe Dimension, but the pipe’s “Size” will always be a Piping – Pipe Size parameter. Duct systems also have an equivalent setup. This is another reason why it is best to have the correct mechanical units for these types of shared parameters.

Built-in pipe Size parameter set in Pipe Size units

Another concern we’ve encountered in our recent work is the use of a single shared parameter across multiple applications or contexts. For example, one of our clients had a shared parameter called “Diameter”, which they would use for pipe connections but also for the diameter of other cylindrical geometries such as expansion vessels. In the short term, this can easily seem like the most convenient and common sense approach. Rather than users having to choose from among various diameter parameters, you can be assured that everyone will use the same shared parameter across different teams, projects, etc.

In the long term, however, this approach ends up tying your hands and introducing confusion. First there is the issue described above of limiting your tags to all display in the same units. By using one shared parameter for every kind of diameter, you can’t have piping tags display a diameter symbol and your expansion vessel tags display in millimeters. But secondly and perhaps more importantly, what happens when a family has both a cylindrical geometry and a piping connection? If you only have one shared parameter for diameter, then either you can’t schedule or tag both, or you end up creating a new shared parameter on the fly to work around the limitation. Usually it will be the latter that ends up happening, which is what leads to having inconsistent and messy shared parameter files over the course of time.

Instead, I prefer taking an approach that can be successfully applied no matter how simple or complex the circumstances. In the previous example of an expansion vessel and heat pump, I would have one shared parameter called “Vessel Diameter” and another called “Water Diameter”. They can be used independently or at the same time as required.

It’s true that such an approach takes more careful planning to determine when you will need multiple shared parameters to cover different circumstances, exactly how specific a shared parameter ought to be, how to effectively review and update your shared parameters file when new circumstances arise, etc. But from my experience working with Revit as an MEP coordinator and family creator, the more work you put into structuring your families and adhering to Revit best practices, the better your workflow and results will be, not only for the present day but for well into the future. And isn’t that what BIM is supposed to be all about?

Render of escalator family from below

New Escalator Family: Revit Content That Will Take You Places

By on February 27, 2018 in Revit Families

You can tell a lot about people by watching what happens on an escalator. Some of us stand calmly in place, waiting for the escalator to do its job. Others march up or down, feeling the satisfaction of saving extra seconds. There are those who seek the comfort of the handrail, and there are those who will never touch it for one reason or another – rock solid balance, possible germs, feeling that tiny bit more alive. Of course there’s one of humanity’s major dividing lines – those who stand to the side so others can pass, and those who stand across the steps, oblivious to the needs of their fellow travelers (you know who you are).

Perhaps it’s easy to pinpoint these habits because escalators really are everywhere. There’s hardly a public or large-scale commercial project that doesn’t make use of one – airports and stations, shopping malls, stadiums, theaters, museums, hotels, convention centers… The list really could go on in this case. The escalator’s omnipresence is one reason we chose it as the first step in making good on our 2018 resolution to publish more of our own content.

Andys ride the escalator - render

An escalator is something that AEC firms will need over and over across different projects, but it’s not an easy family to build from scratch in Revit. Nor is it easy to find a manufacturer version that performs well in a project and that’s truly flexible. So we saw an opportunity to build a family that should make a valuable long-term asset to many a Revit content library.

Just as riding an escalator offers a window into personalities, we thought that creating an escalator family would be a great way to demonstrate our habits as Revit content creators. Our generic escalator combines the precision of a manufacturer-specific family with extensive flexibility to meet a range of design criteria.

3D view showing parameters to flex escalator family

In addition to more obvious options like Inclination (angle), Step Width and Handrail Width, the escalator comes with parameters for fine-tuned control of options like Step Depth, Step Run, Skirting Length, Floor Plate Length, Floor Plate Width and more, with most being independently controllable for high level and low level. We’ve packaged these options as a default type that you can quickly and easily modify to create custom types for specific design criteria.

We’ve also included electrical connectors for the motor on the upper level. And we’ve applied custom materials for step tread to give it that true escalator look in renderings and 3D realistic views. In terms of design workflow, our escalator is built using a 2-level family template, which makes it simple and straightforward for the user to correctly attach the high and low levels to a building structure. If the building levels are ever moved, the escalator will automatically adjust to stay connected.

Escalator Revit family in 3D fine realistic shaded

We’ve pushed ourselves to make this escalator a mean and lean machine. So we’re proud to deliver such a complete family in a file size of just 650 KB. For just $129, we’d say it’s a steal! So check out the escalator in our store, and see how it can help take your Revit family library to the next level.

P.S. – To our dear blog readers, we’re offering an even sweeter deal. For one week only, get our escalator Revit family for just $99. Just use code GOINGUP at checkout before midnight US Pacific on Wednesday, March 7th.

New year calendar

5 Revit Family Resolutions for 2018

Now that the holidays are over and we’re back at work, it’s time to capitalize on that last drop of holiday spirit and get cracking on our New Year’s resolutions! For those of us at Andekan, making New Year’s resolutions means thinking about how we can make better Revit families, make our customers’ lives easier, make our own lives easier, and keep helping the industry to move forward.

We put our heads together on those weighty subjects, and below are five resolutions we decided to make for the year ahead. If there’s one thing that connects all of them, it would be something like “focus on the fundamentals”. The past year was exciting in terms of a clearly growing interest in Revit content, but it was also a reminder that Revit, in many ways, is still in its early days. As the market keeps growing, we want make sure that we continue to provide a strong foundation for high-quality Revit content.

So, to stop procrastinating and get down to it, here are our 5 Revit Family Resolutions for 2018:

1) Educate manufacturers about good cut sheets.

For creating Revit families, 2D cut sheets are far and away the best reference material. This still sometimes catches manufacturers by surprise, who expect that we’d want another format 3D model. But even once we have cut sheets for a project, it’s not unusual for them to have what can seem like minor inaccuracies: they’re missing an accessory option, have an incorrectly labeled dimension, show incomplete connection options, etc. The problem is that sometimes these minor details turn out to be major headaches and additional costs for creating good Revit families. And usually the person requesting the content is not the person who makes the cut sheets, so getting answers or additional drawings can be a time consuming and challenging process.

Exhibit A of a great product cut sheet for building Revit families

Exhibit A of what a great cut sheet looks like: lots of dimensions labeled on the drawings, clear table for values, and some text notes on connections and installation options.

In an ideal world, manufacturers would create their product cut sheets with BIM design applications in mind. In the meantime, we need to try and make it more baseline knowledge that good 2D cut sheets lead to good Revit families. To start, I foresee an update to our website’s content request form and at least one dedicated blog post on the topic.

2) Ask Autodesk for the things that matter most.

Everyone has a laundry list of things they would like to see in Revit, and it’s easy to spitball a dozen things that might seem like “no brainers” for Autodesk to add or fix or improve. That’s just the nature of building a popular software product. But if we narrow in on the things that really affect the ultimate value we can provide to our customers – not just things that make something take a bit longer or add a few kb in file size or seem unnecessarily complicated – then we end up with a much smaller list.

What would be on your Autodesk Revit wishlist?

What would be at the top of your Revit wishlist?

One of those would be the ability to hide/deactivate unused system connectors in a project. The current lack of this feature means that, in order to avoid potential errors, we often have to split what could otherwise be one family into multiple families that cover for the different connector options. This in turn leads to the customer facing additional cost and files and versions to manage over time.

Another item at the top of our wishlist would be the ability to drive material parameters using formulas. Being able to do this would mean being able to further minimize the number of geometries used in a family, which would of course streamline the modeling process. It would also allow a material to be set as instance specific, making families more flexible and increasing their usability for the customer or end-user.

We assume these and similar issues must affect other Revit content providers, and it would be great if we could find ways to more consistently and collectively beat the drum on these things to Autodesk.

3) Publish more of our own content.

After a long stint on the backburner, we finally dusted off our Revit person family, Andy, and re-worked it into a whole new version with better and more flexible geometry. We also created a series of standard types to make populating views with Andy faster and easier. Andy 4.0 was well received, and in the process of making it we realized we have plenty of other good material to work with and publish. So be on the lookout for more Revit families and content packs from us in 2018, including new versions of Andy. In addition to more of the MEP content we’re known for, like our piping packs, we’ll be sure to do more signature families as well, like our airplanes pack, and perhaps even some architectural families that are harder to come by. If you have any special requests, please leave a comment and let us know!

Andy parent and child sitting types

Why there’s a whole world of Revit families just waiting for us out there!

4) Contribute more to conversations on Revit family standards.

In years past, we were pretty active participants in meetings and groups related to Revit standards, including Jose Fandos spearheading the launch of the Product Data Template standard with CIBSE in the UK. More recently, however, we’ve had our hands full working on our own Revit data project, i.e. Kinship, and we haven’t had as much time to spend on standards. We also grew a bit frustrated with the pace of standards development and adoption, despite knowing that these things operate on a long time horizon.

Getting ready for a debate

We have some very serious thoughts that we’d like to share with everyone.

But last year we saw some things that encouraged us to jump back into the pool of Revit family standards and standards work in general. First, we continue to field many of the kinds of questions and concerns about Revit content that we think standards could and should help address. Our long-format post on 10 Key Specs for Revit Content was meant to be an effort in this direction, and it was great to receive enthusiastic feedback on it from both manufacturers and design firms. Secondly, we see the technology landscape – because of the growth in Revit-only projects, the Revit API and the Revit developer community – finally reaching a point where standards can become more easily adopted throughout the project and data lifecycle.

At the same time, we believe that the best standards will be the ones that look beyond the Revit format and think in terms of pure information standards. This is why Jose brought the idea for the PDTs to CIBSE and why CIBSE supported it, because it’s designed as a basic information standard that can be used with any software or media format. Revit content can certainly benefit from it, but so can every other software and that fact is a big part of what makes it compelling to manufacturers and the industry. So that’s a perspective we’d like to continue bringing to the table on standards. Our goal for 2018 will be to see how much time we can squeeze into our schedules for joining in discussions or starting our own.

5) Continue preaching investment in Revit

This one might seem blatantly self-serving for a Revit content company, but hear us out. We still get questions and requests about BIM content for formats other than Revit, and we find ourselves repeatedly making the same case to different parties that they should focus their investment on Revit. Ok so it might be blatantly self-serving after all.

Einstein writes "duh" on the blackboard

Should firms and manufacturers invest more in Revit?

Still, we think that firms and manufacturers also stand to gain by focusing their technology efforts on the most robust and widely used platform. We often see other formats requested in order to cover edge cases (“we want to have it in case someone asks for it”), but we believe successful innovation is driven by solving the majority use cases in thorough and exceptional ways, especially when it comes to early stage technology markets like BIM. In 2018, we’ll try and shout that message from the mountaintop more often.

There you have them, our 2018 Revit family resolutions! We look forward to seeing how we’ve done on our list come this time next year. In the meantime, hopefully this post has brought a bit of inspiration to the start of your year.

Andy the Revit person as the Vitruvian Man

Introducing Andy 4.0: He’s Everyone’s Type

By on December 5, 2017 in Revit Families

Meet the latest version of our human Revit family

Back when Andekan first started, we built a Revit person family that we called Andy. Andy was a chance to show off our Revit family-fu, while offering something that anyone working in projects would find useful.

Andy was an immediate hit with design firms and consultants looking to quickly bring their 3D views and renders to life. Subsequently, we managed to put out a couple more versions that extended his capabilities. We saw a bright future ahead for our dear Revit human.

Andy Revit family living room scene

But Andy, distracted by his early fame, soon fell in with the wrong crowd and his life spiralled out of control. By which of course I mean that we, his makers, got distracted by other priorities and never quite got back to giving Andy the attention he deserved…until now!

Today we’re excited to re-introduce Andy – back and better than ever for Revit 2017+

Our new Andy 4.0 is a breeze to use and packs a lot into his slender 676KB frame. The family comes with 48 pre-defined types covering a range of common actions and body profiles. Quickly select different types to populate your views with scenes of men, women and children walking, standing, sitting, running and more.

Andy person Revit family range of types

Andy 4.0 is available for just $48 USD in our content store. And we’re offering a special deal for our blog readers eager to get their hands on this versatile Revit family. You can save 50% if you purchase Andy 4.0 before the end of the week. Just use code ANDYRETURNS at checkout before midnight US Pacific on Friday, December 8th.

Here’s a taste of some of the many shapes Andy 4.0 can take. Whether male, female, big or small, Andy can do it all.

Andy types walking

Well, you can tell by the way I flex my walk, I’m a Revit man…or woman, or child.

Andy types running - side view with model lines

Who remembers that scene from Total Recall?

Andy parent and child sitting types

Mom, where do Revit families come from?

Head over to our content store now to get your copy of Andy 4.0 and find more details on all the ways Andy can appear in your project views.

Indoor ceiling-hosted VRF components

VRF Systems Summer Showcase

By on August 28, 2017 in Revit Families

While it’s only August, so far it would be safe to say that 2017 has been our hottest year on record for VRF Revit content. VRF stands for Variable Refrigerant Flow, and it’s a type of HVAC system that can do modulated and mixed heating and cooling. We’ve had multiple projects from multiple manufacturers and created a wide range of VRF components throughout 2017. This made me curious to learn more about where VRF products fit in the industry and why the sudden increase in interest.

While we don’t know the exact reasons for the uptick in requests for VRF Revit content this year, we do know that VRF systems are steadily gaining in popularity. This is especially true in the US, where they are still only a small fraction of installed systems. VRF is a technology from Japan that’s been available since 1982 and which is already in wide use across Asia and Europe.(1) It’s more energy-efficient (by modulating the level of refrigerant instead of using a simple on/off) and more flexible (by doing mixed heating and cooling) than other HVAC systems for many common building applications. As a global market, it’s already worth more than $10B and is projected to reach more than double that in the next 5 years.(2) So perhaps it should come as no surprise that more AEC firms are looking to use VRF systems in their projects, and that this translates into manufacturers making more VRF Revit families.

From a content perspective, the main complexities tend to be connectors and ensuring that all technical specs are accurate for all types. With connectors, VRF product line-ups can have units with multiple numbers, types and locations for system connectors, such as units with options for heat recovery, drain pumps and filter boxes. In terms of technical specs, such as electrical and piping data, certain VRF units can have a whole host of possible configurations, some of which may not be immediately clear from standard product documentation.

With both system connectors and technical specs, the critical step is to talk through all product options with the manufacturer and not just rely on documentation. Even if you don’t end up incorporating every product option into the Revit family – because some are too customizable or very rarely requested or not useful for Revit’s purposes – it’s important to know the full range of possible configurations and ideally to create content that can easily incorporate them in the future.

Below are some highlights from our recent VRF projects where you can see the different types of components and the range of sizes and configurations that go into a VRF system. While the family geometry is generally quite regular in shape, the exterior connections, knockouts and grilles help to keep us on our toes. Getting those small details right is important both for recognizing the desired product/configuration as well as for accurate coordination and calculations in Revit.

The families all include three levels of detail in both 3D and 2D and have materials applied for 3D fine views and renderings. Where appropriate, they also include clearance zone geometry (in both 3D and 2D), optional hanger visibility, connector position options, and type catalogs to cover different sizes and technical configurations. The families range in file size from under 400KB for the Y branch fittings to just over 1MB for some multi-unit outdoor pumps and multiport distribution controllers, with an average of about 700KB, giving you top-notch usability and smooth performance in your Revit projects.

Outdoor heat pumps with heat recovery capability.

VRF outdoor heat recovery Revit families

Indoor underceiling and cassette heat pumps.

Indoor ceiling-hosted VRF unit Revit families

Ceiling void indoor heat pumps.

Indoor ceiling void VRF unit Revit families

Indoor exposed and recessed floor model heat pumps.

Floor model indoor VRF unit Revit families

Indoor exposed floor heat pump in elevation view with subcategories showing.

Exposed floor VRF unit Revit family in elevation view with subcategories showing

Indoor exposed floor heat pump with knockout options highlighted.

Exposed floor VRF unit Revit family with knockout options highlighted


Underceiling heat pump with standard knockout (left) and optional drain pump (right).

Underceiling VRF unit Revit family with standard drain connectionUnderceiling VRF unit Revit family with optional drain pump

Outdoor twin 30-ton (left) and 18-ton (right) heat pumps

3D view of twin outdoor 30 ton heat pump Revit family 3D view of twin outdoor 18 ton heat pump Revit family

Change-over box units with 1, 4, 8 and 12 port configurations.

3D fine view of VRF changeover box Revit families

Plan view of change-over box units with 1, 4, 8 and 12 port configurations.

Plan view of VRF change-over box Revit families

Y branch pipe fittings for outdoor heat pumps in fine (left) and medium/coarse (right).

3D fine view of VRF Y branch Revit family types3D medium and coarse view of VRF Y branch Revit family types

Rendering of copper Y branch pipe fitting for outdoor heat pumps.

Rendering of VRF copper Y branch Revit family

And that’s a wrap!

We hope you’ve enjoyed this summer showcase of VRF Revit families, and here’s to the continued growth and success of more energy-efficient HVAC systems!


1. Joanna R. Turpin, “VRF Market Expected to Hit $24B by 2022”, The Air Conditioning, Heating and Refrigeration NEWS,, (February 13, 2017).

2. Ibid.


10 Key Specs for Revit Content: A Primer for Manufacturers

Some quick background before we begin

When we started Andekan nearly a decade ago, the vast majority of our customers were architects and engineers who needed Revit content for specific projects. Things have changed quite a bit since then, and today most of our customers are manufacturers who want Revit families of their products to distribute to those same architects, engineers and contractors.

While building product manufacturers are increasingly alert to the importance of having their products in Revit, most still remain in the dark as to what they should be looking for from their content. We regularly field inquiries from manufacturers who have paid handsomely for content from other providers that’s woefully inadequate if not unusable, or who know they need content but have only a vague idea as to what that means.

We wanted to create this primer as a resource for manufacturers seeking quality Revit content. Our aim is to help shed light on questions of how to evaluate potential content partners and how to determine if your Revit content will be satisfactory for use in actual projects (as opposed to in a content provider’s demo).

The list below covers 10 key aspects of Revit families that we at Andekan think about whenever we’re defining specifications for a content project. While the list is not exhaustive in terms of how you can specify Revit content, it should be sufficiently comprehensive for manufacturers buying content to get a solid grasp of whether they’re getting what they pay for.

Of course there are other ingredients that go into high-quality Revit content development, such as clear product documentation and good model QA. But those are beasts of a somewhat different nature and substantial topics in their own right that deserve their own posts or primers. So without further ado, here are our…

10 Key Specs for Revit Content

#1 3D Geometry – Keep it clean and use all levels.

Revit family rendering

3D is the one thing that anybody seeking and making Revit content is likely to know about – Revit can do 3D! But the devil is in the details, and there are some key ones for manufacturers to be aware of:

Levels of Detail. 3D geometry can be defined at three levels.

Revit offers three levels of detail for viewing 3D geometry: Fine, Medium and Coarse. Your Revit families should make use of all three. Fine geometry should be detailed enough that you can tell it’s your product, or at least tell the exact kind of product (some product categories are more generic-looking than others). Coarse geometry should just show the geometrical mass, since it will be used for simplified views. Medium, as the name suggests, should be somewhere in between those two, with the appropriate amount of detail being different for different product categories.

Revit 3D view in three levels of detail

3D views of a Revit family at three levels of detail – fine, medium and coarse

Logos and Branding. Not helping your image.

Logos and other pure branding elements are to be avoided, as they only add to the model’s complexity, file size and constraints, without serving any purpose within Revit. Adding them might quell the fears of your sales and marketing team, but not the needs of your customers working in Revit. In fact, any logo included on a Revit family will end up looking like nothing more than a blob or dot at most view scales needed for project deliverables.

Your brand will come through in other ways – parameter data, fine-level geometry that looks like your product, how you distribute your content to customers, etc. Most of all, it will come through in having high-quality content that makes customers happy by helping them to deliver great projects in Revit. Now this rule does have some exceptions. For example, creating a Revit family for a sign that goes on a restaurant or store is a case where modeling a logo simply can’t be avoided. 😉


Native Geometry. The sustainable approach to creating content.

Importing geometry from other formats is a killer for Revit content. Just don’t do it. Ever. This probably deserves its own post to explain, but while we work on that please just trust us and stick to using Revit’s native geometry.

#2 2D Geometry – Revit also does 2D. Don’t skip it.

Revit Front Elevation View - Fine

Surprise! Revit also has 2D geometry elements: model lines, symbolic lines and masking regions. While Revit’s 3D geometry gets all the attention, it’s very important to consider 2D geometry for application in the drawings and sheets that are issued during design and construction.

2D or Not 2D? That is NOT the question.

For cleaner and faster 2D views, such as plans and elevations, your families should include 2D geometry applied specifically to those views. Any professional content provider worth its salt will include 2D geometry as a matter of standard practice. Some will argue that Revit’s view rendering, and computers in general, have improved enough over the years that it’s entirely possible to skip 2D geometry and just use 3D geometry in 2D views. They might be right, at least for certain types of families, and that can be a perfectly acceptable choice at a firm or project level. But when it comes to making Revit content for public consumption, it’s important and worthwhile to cover your bases and include 2D geometry for 2D views. Having good 2D geometry is one of those details that an end-user will really appreciate about good content and which will help keep them using your families in projects.

Levels of Detail, Again. 2D also shows in three levels.

Revit side elevation view in three levels of detail

Revit side elevation view in three levels of detail – fine, medium and coarse.

Just like with 3D geometry, Revit gives you Fine, Medium and Coarse levels of detail for 2D geometry. In general, you should follow the same principles as with 3D geometry, although certain product categories have special requirements based on industry practice for construction documents. For example, pipe fittings should display as model lines only, and light fixtures should display as symbols. Speaking of symbols…

Symbols. Create separately and then nest.

If you need your product to be represented by a symbol in plan or elevation views, then you should create the symbol as a separate Annotation Symbol family and nest it within your main family. And don’t let anyone tell you that a symbol won’t show if your product is placed in a wall, or that you can’t avoid overlapping with symbols from other objects placed in the same space.

#3 Flexibility – Make sure your content can adapt.

The bad news is that product dimensions and exterior appearance usually change over time, and when they do you’ll have to update your content. The good news is that your Revit families can be built to handle this eventuality with relative ease. One of Revit’s key features is the ability to create “flexible” geometry, i.e. you can enter new dimensions and the model geometry will automatically “flex” to the new size or shape. The more flexible a family’s geometry is, the easier it will be to incorporate future changes, and the more likely that a manufacturer can make those changes without outside help.

Wall-Mounted Speaker Types in 3D Fine

Building with flexible geometry makes it easy to add new sizes, angles and options.

It’s also possible to create Revit families with non-flexible geometry, and sadly there are still cases of manufacturers paying for fancy-looking models that break as soon as they try to change a dimension. While it’s true that, for very specific products, non-flexible families are not necessarily a bad thing in Revit, there are still reasons for a manufacturer to keep geometry flexible. Documentation might have mistakes, and a flexible family will more easily cope with such changes at little or no cost. Additional variations of products developed in the future will be able to use a flexible family as a starting point. And for certain kinds of products, say pipe fittings, you want to go the extra length and have geometry that can flex to a whole range of sizes and angles so that the family supports the required workflow in Revit projects.

#4 Types – Define your major product variations.

Types represent different variations of a product or object within a single Revit family – which is why it’s called a “family”. For example, a table that comes in red or blue and 8ft or 12ft could have four types to cover the different length and color combinations that someone might order.

All Revit families contain one or more types for a user to choose from.

Not every product option needs to be covered by a type, and we’ll talk more about other kinds of options below. But every family in Revit will always have at least one type by default. For manufacturer Revit content, there are two key points we always try to bear in mind regarding types:

Define types by your most common, standardized versions.

Types should be used to cover a product’s most common and standardized options. In general, your Revit family types will match up to the different models of your product that you sell. For example, if you sell a lamp with either a circular shade or an elliptical shade, it would make sense to set those options as types within your lamp family. On the other hand, if your lamp is available in any length from 4ft to 8ft, it doesn’t make sense to cover that option using types because there is an open range of possible values. There are also some options that are not possible to cover using types, such as optional electrical connections.

Type catalogs make everything easier.

Types are most convenient when defined using what’s called a type catalog in Revit. This is especially true if there are more than just a few types. The reason is that a type catalog is essentially a spreadsheet, which can be edited and reviewed just like a spreadsheet, i.e. by anyone and without having Revit. So the more information that is fed from a type catalog, the more manageable the family will be for the manufacturer (and for the end user).

It's almost too easy!

On the other hand, we’ve received plenty of requests from manufacturers to update families that use a whole series of complex, interconnected formula parameters to generate all of the type data. Any family created in this fashion takes what should be simple and turns it into something which can’t be updated in a reasonable amount of time, except, perhaps, by the original content provider. In contrast, if you had a properly-built, flexible family that uses a type catalog, you wouldn’t even need to open the Revit family file. Instead, you could take care of any changes purely within the .txt type catalog.

#5 Parameters – It’s all about the data!

Identity Data parameters example

Some of the many kinds of parameters that can go into a manufacturer Revit family

If geometry is one side of the Revit content coin, then parameter data is the other side. Parameters are what define your product’s properties within Revit. Parameters can include everything from physical attributes like width, length and height, to technical specs like materials, weight, electrical or mechanical properties, to identifying information like model number, product URL and, you guessed it, manufacturer. You can add and configure custom parameters for your Revit content, and there are also some built-in parameters that come with the Revit family templates.

A quick compass for navigating the sea of parameters

It would take many blog posts to cover the topic of parameters, and there are many technicalities that apply only to specific types of products or project use cases. For a manufacturer’s purposes, below are some of the most critical things to look out for on your Revit journey.

Render of an oil tanker Revit family

Family Category. What kind of object is it?

Categories in Revit cover major groups of building objects like Communication Devices, Doors, Furniture, Mechanical Equipment, Pipe Fittings, Plumbing Fixtures, Windows and so on. Setting the Category parameter for your family is important. Certain categories come with different built-in parameters that are essential for their use in Revit. The Category parameter is also something that’s frequently used for generating schedules of quantities in Revit, and you want to make sure that your product shows up on the right schedules.

Type vs. Instance. Think “factory set” vs. “on site”.

Parameters in a Revit family can be configured as either “type” or “instance”. The easiest way to think about type parameters is as being for those attributes that define your product and are set at the factory. For example, think of a valve’s “connection type” parameter. If it’s a threaded valve, then it’s so from the moment it leaves the factory and it won’t or shouldn’t change once on site. So that’s a type parameter.

On the other hand, instance parameters should be used for any parameters that need to be in a family but that could or should be changed on site. The lever of that valve can be open or closed, but that’s something that can and should be changed on site, and it doesn’t change which threaded valve you ordered. So the parameter used to set the lever of the valve to open or closed would be an instance parameter.

Naming and Grouping. There to help users, not content creators.

Parameters can be positioned under different group labels within a family and can be named however you want. Usually, you just want to follow the logical groupings that you get in Revit, so that you put your electrical values in the Electrical group and the outer dimensions under Dimensions. But we also recommend putting “background” parameters (ones that are used for special options or as part of formulas) into the Other category so that they stay out of the way for users and anyone marketing the content.

In terms of parameter naming, clear and concise is always the best approach, especially with those that will need to be used in a project. Make sure they can be easily understood by your customers and users. Autodesk’s own out-of-the-box content takes this approach, with plain English labels that use Title Case for Their Words. Leave any clever formatting like CamelCase, lots_of_underscores or ACME_Prefixes, where it belongs, in the hands of any customers who are so inclined to use them.

Formula-Driven Parameters. Don’t get carried away.

Parameter values can be defined using a formula, and those formulas can reference other parameters, and thus many complicated things can be achieved using formula parameters in Revit. It’s hard to avoid using any formula parameters if you want to do something fancy with a Revit family’s geometry or parameter values. On the other hand, the more functionality that you pack into formula parameters, the harder it becomes to manage a family over time. Even if all the individual formulas are simple, you are also adding logic that will need to be understood, modified and re-checked any time you need to make a change. And if your families use formula parameters to generate type values, then you’re highly encouraged to go back and read section 4 on the virtues of type catalogs.

Shared Parameters. As few as possible helps everyone.

If you’re building in-house content for an AEC design firm, then by all means you should include the firm’s shared parameters in your Revit content. On the other hand, shared parameters are generally a bad idea for manufacturers developing content for public distribution. Why? Because AEC firms don’t all use the same shared parameters. Sure, there are some public lists of shared parameters for different industry groups that get some usage, and it can make sense to include those if you know that most of your customers are using them or have asked about them. On the other hand, having unwanted shared parameters is a pain for users, so leaving them out keeps your Revit families neat and tidy for everyone. Those that want to add their shared parameters can still do so, and in general that process is one they’ll likely have developed to be easy and efficient.

#6 Options – Include, Split or Skip?

Alice in Wonderland - Which way to go

It’s always critical to account for any options that need to be available for the end-user in Revit. These could be mounting options, accessory options, technical options, etc. The way that options get incorporated into your Revit content will vary depending on the nature of the option and how commonly it’s used. But in many cases, such as with clearance zones described below, you can configure a checkbox parameter to toggle options on and off by linking either to your model’s geometry or to other parameter data.

In other cases, you may end up going so far as to create a separate version of a Revit model to cover a desired option. This could either be because Revit requires it (e.g. a motor accessory that brings with it an additional power connection – see below for more on connectors) or because it’s just more practical for the end user (e.g. your product has an option that’s required for use in a certain commercial or geographic market and is never used in any others).

There are also cases where it will make the most sense to NOT cover an option within the Revit family. Maybe the option is so rarely needed that you don’t want to confuse users, or maybe it’s something that must be customized per order, or maybe it simply wouldn’t be useful within the context of a Revit building project. In all of these cases, your content provider should be able to walk you through the possible approaches and clearly describe the pros and cons of each.

#7 Clearance Zones – Give your families their space.

Gas Meter - Clearance Zones - 3D

Gas meter Revit family with clearance zones showing.

Whether it’s for purposes of access, maintenance or safety, many types of building products require a certain amount of space around them. Since Revit is used heavily as a coordination tool, it’s critical to include these clearances in your Revit families. Clearances should be modeled in both 3D and 2D views, and you should be able to turn them on and off using a clearly named parameter. It’s best practice to assign clearance zone geometry to its own subcategory within the model, at least until the day Revit does the right thing and provides a built-in clearances subcategory.

#8 Connectors – For MEP system parts and equipment.

Revit family with many system connectors

Revit family with multiple MEP system connectors. Connectors highlighted in right-hand image.

If your product makes use of, or is a part of, a building’s electrical, plumbing or HVAC systems, then your Revit family will need one or more system connectors. As the name implies, connectors allow a Revit family to become part of a building system so that its properties are taken into account for purposes of calculating loads and flows. Certain types of products will only need one connector (e.g. light fixture), whereas others will need multiple connectors of the same type (e.g. pipe fittings) or multiple connectors of different types (e.g. HVAC equipment).

Connectors have their own systems-related properties, which are not shown in the Revit family parameters that are readily visible to the end-user. However, some connector parameters can be linked to family parameters, which a user can readily select or modify. Linking connector parameters to family parameters gives users a way to easily set key system-related properties that they need for project usage (e.g. selecting the right voltage type).

Failing to include a connector in a model that should have one, or configuring connectors incorrectly, can negatively impact an entire project, so it’s very important to get them right for MEP manufacturers. It’s also important to be aware that system connectors have certain limitations in Revit. For example, if your product comes in variations with different numbers or types of system connections, then you’ll need to produce multiple Revit families to cover those varying connector options.

#9 Hosting – Where should I put this?

butler with a serving tray

“Hosting” in Revit refers to how an object can be placed in a building space. Does it need to be placed on a face, in a wall, on a ceiling, or can it be placed anywhere (non-hosted)? Hosting is a critical choice, because once you pick your hosting type template for a Revit family, you can’t easily change it.

Aside from a small number of special cases such as windows or doors, you generally want to pick either non-hosted or face-based hosting. While there are more specific options available, like wall-hosted, ceiling-hosted and floor-hosted, more often than not those choices only serve to unnecessarily constrain a family’s usability within a project. There can be vertical and horizontal design faces in Revit that are not strictly categorized as walls or ceilings or floors in the project, so having a face-based family usually makes it easier to place “hosted” content where it ought to go. And anything that doesn’t actually affix or mount to a surface can simply be non-hosted. Again, there are cases where more specific hosting is appropriate, so it’s an important choice to ask about if you’re not sure what makes sense for your products.

#10 Version – If I could turn back time…Revit can’t.

Delorean dates generator machine

Similar to hosting, this is a choice that can’t be reversed, so make sure you choose wisely. The key constraint with Revit versions is that content can never be downgraded to earlier versions, although it can always be upgraded to newer versions. So if you build your content in Revit 2016, then you should be okay NOT having it available in Revit 2015 and earlier.

There is always a tradeoff between making content that is backwards compatible, and therefore available to the largest possible number of users, and making content that takes advantage of the latest and greatest in Revit. Autodesk officially support the current version of Revit and three versions prior, so that’s a good reference for how far back most content ought to go. And remember, Autodesk generally release the next year’s version during the current year, i.e. Revit 2018 has been out since the spring.

However, if you know that a lot of your customers are still working in Revit 2013, for example, then it probably makes sense to go an extra year back and do the content in 2013 to make sure you can continue serving those customers. In certain cases, you may then need to tweak or want to optimize the content in later year versions (for example, embedding lookup tables in pipe fittings from Revit 2014 onward). But that effort will generally be minimal compared to rebuilding a family from scratch because it got made in a too-recent version.

#11 Project Workflow – btw don’t forget context.

Amp volume goes to 11

This blog post goes to 11.

We always want to go the extra mile for high-quality content, so of course we had to squeeze an 11th item into our top 10 list. But project workflow is less a single spec on a checklist and more a question of the “real-world” understanding that’s required to apply the checklist to different types of objects and products. It’s understanding how those objects need to get used within a Revit project (workflows), and the features and options that Revit has available for achieving those workflows.

To give an example, although we highlighted types and type catalogs in multiple places above, if someone ever gives you a pipe fitting Revit family that uses a type catalog or that has types for different angles (e.g. a bend with 45 degree type and 90 degree type), then you should run away from that person! That’s because pipe fittings use another special feature in Revit, called a lookup table, that lets them accommodate multiple angles within a single type.

So it’s essential to work with a content creator that has enough experience working in Revit projects to understand your product’s required workflows and how best to achieve them. At Andekan, on top of our 10 years dedicated to creating top-quality Revit content, our team has another 10 years combined experience working as coordinators and consultants for real-world building projects. Whoever you work with to create content, you should feel confident they have the experience to connect all of the technical dots in project context.

A quality content creator will be able to describe how your content will be used in a project and to explain which features and options are most important for your type of content. That can be someone in-house who has trained extensively in Revit and talked to all of your customers using Revit, or it could be a consultant who specializes in Revit and your particular industry sector and has design firm clients, or it could be a firm fully-dedicated to Revit content with years of experience doing content of all kinds for a range of customer types, like…hmm, let’s see…well, you get the picture.

That’s it! All done!

Thanks for reading our list of 10 Key Specs for Revit Content! If you’re a product manufacturer developing content, or if you’re a Revit user who works with product manufacturers and their content, we hope this primer has been helpful! If you have questions or feedback, please feel free to leave a comment here or reach out to us by email at

Connected CRD Revit families - 3D Fine

The Limits of Revit System Connectors

System connectors and their limitations have been a recurring theme in a slew of MEP content projects that we’ve been working on recently. When it comes to creating Revit families for MEP systems (HVAC, piping, plumbing, electrical, etc.), connectors are an essential feature of any usable piece of content. Anyone doing system coordination and calculations in Revit projects will know about the importance of having families with the right kinds of connectors, and of having those connectors correctly configured for the particular system (and for those that don’t, you can check out this Autodesk primer on Revit connectors).

Still, when we think about what makes for complex MEP Revit families, we’re usually focused on how varied and intricate the model geometry is, or how to configure parameters and type catalogs to cover a range of technical options. It can be easy to underestimate the impact that system connectors can have on how you should build a Revit family.

Indoor Heat Pump Revit Family in 3D Fine View

Indoor heat pump Revit family in 3D fine view.

Indoor Heat Pump Revit Family Selected with Connectors Showing

Indoor heat pump with system connectors visible.

In part, this is because system connectors in Revit have certain limitations that may not be obvious to engineers who use Revit families in projects, and even less so to manufacturers who hire others to build Revit families for their products. In terms of building MEP content in Revit, the three most critical constraints on connectors are:

  1. Connectors added to a family cannot be turned off – When you add a connector to a Revit family, that connector will be available to use no matter what else you do with the family. You can temporarily hide a connector’s geometry in a particular view, but the connector itself can’t be permanently hidden or deactivated.
  2. A connector’s discipline cannot be changed – Once you’ve designated a connector’s discipline (pipe, duct, electrical, etc.), the only way to change it is to delete the connector and add it again.
  3. Not all connector properties can be controlled via parameters – You can link certain connector properties to family parameters, but some big ones such as System Type and System Classification can’t be controlled that way. This has an impact in terms of covering system specs via type catalogs, and it generally makes it more difficult for end users to manage system connection details within a Revit family.
Connector Properties for Mechanical Equipment Revit Family

Connector properties for a mechanical equipment Revit family.

The big upshot of these limitations is that your fundamental connector options cannot change from type to type or based on other parameter values within a Revit family. This creates complications for certain kinds of MEP equipment that can be configured to have different numbers or types of connections based on their required capacity, application or other factors. Rather than being able to cover the full range of technical configurations within a single Revit model, the model has to be split into a separate .RFA files to reflect these different connector configurations.

Damper Revit family split into three due to varied number of supply air connections.

Ceiling radiation damper Revit family split into three due to varied number of supply air connections.

Damper family with single supply air connection

Damper family with single supply air connection.

Damper family with double supply air connection

Damper family with two supply air connections.

Damper family with three supply air connections

Damper family with three supply air connections.

One might argue that it’s not very difficult to handle this situation – simply save another copy of a Revit family and then just change the connector options, right? To a degree that’s true, but of course the devil is in the details. It might not take much work if you have a very simple set of technical configurations that happen to require different number of connectors. We faced a situation like that with the ceiling radiation dampers shown above, where there could be between 1 and 3 connections for supply air, but the types of connectors were all the same and the impact on geometry was minimal.

Then again, it’s a different story when you’re dealing with things like commercial or retail HVAC equipment that can have an extensive range of operating capacities, electrical specs and system options that all relate to your connectors – including different types of connectors and where those connectors can be placed. In those cases, splitting a Revit family by connectors is no trivial exercise, if for no other reason than the extra care that needs to be taken in configuring the connectors and all related parameters. It can also involve modifications to the model geometry, depending on the product and manufacturer requirements.

Render of Connected Ceiling Radiation Damper Revit Families

Render of Connected Ceiling Radiation Damper Revit Families

The good news is that it is easy to solve for this problem. The only thing that’s needed is the full product documentation from the manufacturer, and perhaps a conversation with them about which options need to be covered within their Revit families. Unfortunately that’s often a process that can take a while or have unanticipated developments, as the people in charge of helping sell and market the manufacturer’s products (i.e. salespeople, digital marketing staff, etc.) might not be the people who handle its technical documentation and product engineering.

Sometimes there are gaps in communication, timing or resources between those areas within a company. In that case, the next best thing to having all of the documentation at your fingertips is to be able to explain why an existing Revit family can’t work for your particular application, or why it’s going to take longer and cost more to create Revit families that cover all of the system options that the products require, or why your company should address that gap and align teams more closely.

So the next time you’re requesting MEP content from a manufacturer or planning to create MEP Revit families yourself, remember to consider the limits of Revit system connectors and how they can impact your models. It’s often the case that, due to connector limitations, an MEP Revit family will need to be split in ways that don’t match up exactly with how the manufacturer packages or sells the product. And if you don’t plan for that upfront, you’ll only pay the price in time and resources later on.

Hopefully this blog post helps anyone facing such situations, and if so then I’ll be a happy writer. Stay tuned for more on system connectors soon. I plan to write a couple more posts about how we can maximize their use and flexibility within Revit families, despite their limitations.

Type Parameters in an Andekan Revit Family (Left) vs. Another Content Provider (Right)

Built to Fail: A Study in Contrasts with Manufacturer Revit Content

After my last post on building manufacturer Revit content that can easily flex to accomodate new dimensions and specs, we received a customer request that offers up a perfect study in contrasts. The customer in question is a manufacturer with existing Revit families that had been made by some other provider (unknown to us) and later published on Seek. The manufacturer now wanted to add a few new types to those families, each of which had only minor changes to dimensions and electrical specifications. Sounds simple enough, right?

When we actually opened the families in Revit and took a look at the parameters, what had seemed like a quick and easy job revealed itself to be a nightmarish labyrinth. All of the type parameters were controlled by lengthy IF formulas that referenced a slew of opaquely named parameters. The below images are just a portion of the parameters that drove the type data for these families.

Poorly configured Revit type parameters - example 1 of 3
Poorly configured Revit type parameters - example 2 of 3
Poorly configured Revit type parameters - example 3 of 3

How do you update Revit content like this? Well, you could spend hours picking apart the formulas and tracing the parameter references to hopefully figure out the “simple” update that’s needed to add a new voltage value or stretch an outer dimension by a few inches. Of course there’s always the possibility that you miss a step the first time or that your mind goes numb before you can get to the end of the maze. And even if you do manage to decipher how to add your new type values, you better re-check all of the other types afterward to make sure you didn’t accidentally affect any existing data.

It’s possible that whoever originally created the content has some tool or spreadsheet that they’ve configured to easily add new type values and generate all the correct parameters and formulas. But it’s truly a disservice to the customer to build content that they can’t maintain independently (either directly on their own or by working with any reputable Revit content provider). This is especially true when there is an existing, standard tool called a type catalog that can make the same process as easy as modifying or adding a row in a spreadsheet.

So what can you say to a customer who brings you families like this with the expectation of quick and easy updates? In this case, we knew that trying to update the existing Revit families would take us just as much time (and with no added value) as it would to rebuild the families from scratch. So we told the customer that they had two options — 1) go back to the original content provider to have them update the existing families, or 2) have us rebuild the families and gain the added value of better long-term management through flexible geometry, clearly named parameters and type catalogs. While that may not have been the answer that the customer was hoping for, their response was to avoid the previous content provider and request a quote from us for rebuilding the families.

To illustrate the contrast, below are samples images of the type catalog and type parameters from one of the manufacturer-specific Revit families that we highlighted in our last blog post.

Type catalog for manufacturer-specific Revit family created by Andekan Concise type parameters for manufacturer-specific Revit family created by Andekan Clearly named type parameters for manufacturer-specific Revit family created by Andekan

If Revit content is done right the first time, then you get great value from Revit’s parametric design and family data structure – then jobs like this one really can take 5 minutes. On the other hand, taking the wrong approach to parameter data or geometry can turn simple updates into such a complicated job that you’re better off ditching the content altogether and starting from scratch. Perhaps the biggest challenge is to tell the difference between the two, since Revit families that are poorly built can still look great in 3D views and still give you the parameter data you need today. Often problems don’t surface until down the road, when the content die is already cast and it’s too late for quick fixes.

Daikin Chiller Revit Family - Perspective Raytrace

Built to Last: Manufacturer-Specific Revit Families That Are Made to Flex

By on February 22, 2017 in Revit Families, Revit Family Standards

We were hired recently to create a few chiller Revit families for use by a major engineering firm. The firm requested the families to be based on specific manufacturer models that they needed for a particular project, but they also wanted to get Revit families that they could readily adapt to future needs. The project was a good chance to demonstrate how Revit families can be built to match a specific manufacturer product while still being flexible enough to serve as the basis for a range of similar products from the manufacturer.

The chiller Revit families we created were based on the Trane Series R, the Climaveneta TECS2 HC line and the Daikin EWWQ-B-XS. We modeled the geometry for these families to our usual standards – three levels of detail in 3D and 2D, with materials applied in 3D Medium and Fine views, and with only symbolic lines and masking regions shown in 2D views. The results are beautiful and accurate 3D views along with clean and fast 2D views.

Climaveneta Chiller Revit Family - 3D Fine View
Climaveneta Chiller Revit Family - Front Elevation Fine View

While we modeled these chiller families to match real-world products from the manufacturers, we also made sure to include a high degree of flexibility into their geometry. We did this by incorporating a variety of parameters that can be used to control all the individual elements of each Revit family, such as diameters for the compressors, evaporators and condensors, as well as the spacing of geometries about all three axes. Below is a sample of these parameters from the Trane chiller family.

Trane Chiller Revit Family Parameters - 1 of 3Trane Chiller Revit Family Parameters - 2 of 3Trane Chiller Revit Family Parameters - 3 of 3

Having this set of parameters available means that a Revit user will easily be able to modify the families without having to dig into the details of their geometry. Although the engineering firm that requested the content only needed a single version of each chiller, now any experienced Revit technician on their staff can quickly update a few parameter values — or a line in the type catalog — to add new capacities or models within the manufacturer’s product range.

Trane Chiller Revit Family - Plan Fine View

Trane Chiller Revit Family - Perspective Render

There is still a common misconception in the world of Revit that there should be different approaches to creating manufacturer-specific content versus “generic” content. The truth is that any quality Revit family can and should be built to flex, even if it’s created to represent just a single manufacturer product. It’s one of Revit’s best and most important features, and it’s how you create Revit families that will last and keep providing value product after product, project after project. As a perfect case in point, we heard from the client that, within days of receiving these families, they had already modified one of them to cover three other models from the manufacturer with minimal effort. And that’s how we know we’ve done our job and delivered Revit content done right.