Revit and IES

[ron.sanpedro]

Is anyone using Revit and IES Virtual Environment yet? How easy is it to get a Revit model into VE? I am curious about the actual work flow, especially I am wondering if you have the option to either link or import the RVT file, in effect. We often want to do analysis on a more static model, so an import would actually be superior, most of the time.

Thanks,
Gordon

[Andre Baros]

At AU there was a demo showing IES inside Revit. I could not get any more information, but the demo made it pretty obvious that this functionality was coming.

[ron.sanpedro]

At AU there was a demo showing IES inside Revit. I could not get any more information, but the demo made it pretty obvious that this functionality was coming.

I know IES inside Revit is in the works, but my understanding is you can use IES VE and import a Revit model. We actually prefer that, as much of the initial energy and lighting analysis happen in parallel with the building design, and working with a snapshot rather than the live model is a better approach early on. Crossed fingers!

Gordon

[archjake]

I believe that Revit Systems will export to IES directly for lighting analysis. Revit Building needs to export to export to a ODBC (I think) database before IES will import it.

We have not had time to play with this yet, but I have an intern who is going to take a look at it.

What was shown at AU was quite amazing and useful.

[s.messing]

I came into Revit with a desire to be sustainable and to be cutting edge. From the very beginning I thought, "Oh, here's this great software (Revit) and this great idea (sustainability). I'll be able to combine them and use one to benefit the other..." So far, even with research, some outside guidance, and a genuine effort on my part, I have come up way way air-ball short.

I have been hearing rumors about Beta Testing and other IES VE/ Revit stuff, but I have seen nothing in practice. I have heard that both at Greenbuild and at AU there were great demos in IES. I have not yet heard of anyone actually integrating the two software platforms for better and more efficient design and then showing some result. So far, all I have seen is marketing from people within Autodesk or people affiliated with Autodesk. I am surprised, but really very disappointed to find out that a lot of this (real, efficient, time effective) energy modeling and sustainability talk is simply hype at this point. Maybe it is that no one really wants to share with me.

Furthermore, on a parallel subject, I successfully exported a model from Revit (Building) into gbXML last week only to find out that the results appear to be mediocre at best. It raised more questions than answers. I wound up with a few pages of information that looks like it will be discounted easier than it could be proved factual...

So, now I have officially vented my frustration about the slowness of the realistic implementation of green practices into Revit Building (from a personal standpoint), maybe someone will combat my statements with proof that the interface between these energy modelling softwares and Revit is being exploited for the good of the earth. I hope this rant does not come across as hyper critical.

I have very high expectations for Revit, myself, and the future designers of this planet and I think every little bit counts. Autodesk is one of the biggest, most widely used software companies in the world and they have a great product with Revit. They have made commitments, agreements, and formed relationships with the USGBC and with companies who specialize in sustainability. Now I want results! I will take any and all feasible advice about how to get better buildings built. I have chosen Revit as a path to attain better, more integrated buildings. I have continued to push my firm to move forward with this promising product. Now I want more! I want to be able to show them how to get solar studies, energy analyses, and life cycle costs from the same product that is modelling the building. I want to be able to make important design decisions earlier and with better base knowledge. Like Morrison said, "We want the world and we want it now!"

Thanks for listening to my rant,
Stephen

[hweiler]

Thanks for the input above...it's good to know that I am not loosing my mind.

Our office just started using Revit a couple of months ago and lately I have been investigating options for energy modelling using Revit. So far, here is what I have found (be prepared for a long read!):

From what I understand, both Green Building Studio and IES VE (not the integrated Beta version) require that you export your Revit model into gbXML format. I tried using GBS first with a few minor stumbling blocks: 1) In Revit I had simply made a concrete "slab" as my floor rather than using the "floor" tool. When I tried to run the gbXML file through GBS, I got an error message saying that some of my enclosure surfaces were missing. Since the feedback from GBS was pretty generic it took me awhile to figure out that gbXML does not recognise a "slab" as a floor. Pretty quick fix once I figured out the problem. 2) Materials do not translate into gbXML therefore you first must run the simulation once and then do a "Design Alternative" to assign the correct materials and run the energy modelling again. So basically the first run is a throwaway (but you still have to pay for it) and the 2nd actually incorporates your materials and R-values.

So I finally ran my model through the GBS software, input the correct materials, etc and was able to print the results, which as I found out later were pretty poor energy-wise. After reading through the packet explaining how to put Revit through GBS again I found at the very end of the long printout a statement saying "Overhangs, fins or any exterior shading surface currently are not exported to gbXML by Revit. Please contact Autodesk to determine when the above elements will be supported.". I also emailed John Kennedy (who is the contact on both the gbXML website and the Green Building Studio website) and he confirmed that there was no way to translate this information into gbXML and that it was a "Revit problem". Being as I know very little about computer programming, can't say whose fault it is, though it seems to me that the translator would accomodate the file format being translated and not the other way around. When it comes down to it, whose fault it is doesn't really matter since the bottom line is that your solar shading devices do not translate into gbXML format. That makes for pretty innacurate energy modelling if you ask me.

Another broader problem was that I could not figure out how to see my model after it translated, to assure that it was importing correctly. Does anyone know of a (preferably free) gbXML reader/viewer ? Is gbXML simply a coded format to import into GBS (and other programs), or can it even be seen in 3D? After finding out that my overhangs were not translating it made me start to wonder what WAS actually translated into gbXML.

I have heard from several co-workers who attended Greenbuild that IES VE and Ecotect are 2 other options. As stated above, it seems that the non-beta version of IES VE also requires gbXML format. Though I didn't find much info on the their website, I did get some responses from their tech support to answer some of my questions. In regard to my question "Can models be imported into IES or does one have to build a model from scratch in the software?" the response was "At the moment we are developing (in partnership with Autodesk) a direct link to Revit systems, which will allow you to generate loads from your model from within Revit. Alternatively you can use a GBxml export." another IES VE employee responded "Our program, the <VE> as we prefer to call it, does in fact import Revit models directly using a proprietary link that has been developed exclusively with AutoDesk. As of now, this link is still in the Beta version of testing and so requires that you sign a non-disclosure agreement before you can update your software to activate the link. We're working hard at IES to fine-tune this link, and provide a head-ache free way for architects and engineers to import directly from Revit, with the click of a single button."

One advantage to IES VE over GBS is that even though they both use the gbXML format, IES VE has it's own 3D modelling software built-in. I haven't tried it yet, but it seems logical that after bringing your translated gbXML file it into IES VE you could add overhangs and louvers back if they don't come in and correct any problems before running your energy modelling. Certainly not ideal, but better than the GBS situation where you simply send your model sight-unseen and get back data. As far as I can tell GBS doesn't have a built-in 3D modeller, so you can't see what your translated model looks like before running it.

Then there is Ecotect. One of the file formats compatible with Ecotect is .dxf which can be exported directly from Revit. I don't know much about this file format, but according to a co-worker, it has less (if any?) embedded material information, so it seems that a lot of the parametric information inherent in Revit (ex: wall assemblies) would not translate into the dxf. As far as basic 3D volumes translated (not parametric data) I have no idea since I haven't tried to export the model yet. Since Revit allows you to translate into .dxf without the need for installing supplementary software, I suspect that the 3D info may be more accurate than gbXML. As I said, I haven't tried it yet, so all of this is speculation. However, on the Ecotect Help under "Critical Information" page (available once you download and install the software) it seems that they are strongly encouraging that you build the model in Ecotect rather than importing the file. Something about dxf files ignoring embedded data. That seems congruent with what my coworker said about materials.

At this point I am considering doing the IES VE beta testing since it works directly with the Revit file without the need for translation. As far as a second choice it would be split between regular IES VE using the gbXML format or Ecotect. If the dxf format proves to include more information when the Revit file is translated (opposed to the gbXML), then Ecotect may prove a better choice. Of course, that also depends on the user-friendly nature of the programs. As I said I have not actually tried using either IES VE or Ecotect mostly because they look REALLY complicated and I am trying to figure out the path of least resistance before spending time learning a whole new program.

If you have any more input regarding these or any other energy modelling programs with regard to Revit, please, please, please add your comments! There has to be someone out there who has more technical knowledge than I who has attempted to do energy modelling with Revit.

[kyle.bernhardt]

This seems like a great thread to chime in on. It's also quite helpful that earlier this week our press embargo lifted and I can actually talk about what's included in our upcoming release.

I will try and address many of the concerns and points you all have regarding this subject, but I can't deliver the be-all-end-all source for technical information on IES, Revit, and gbXML...at least in one post. I'll try and touch on as much as I can, feel free to ask any questions that you may have, I'll try and answer them.

First, to address Stephen...well put. Although I can tell you have a lot of emotion on the subject, this is an emotional subject, so I understand where you're coming from. There is an extremely important need for more sustainable design practices in building design. The end result of such practices, if carried to fruition, are buildings that have a drastically smaller environmental footprint. This is not something that is lost among us at Autodesk, we get it, and share your passion on the subject.

We at Autodesk have the unique opportunity to help drive the industry in that direction by providing design tools that facilitate such practices in a user friendly, productive, and accurate manner. A big part of "sustainable design" is knowing the impact of decisions you make, and being able to quantify their impacts. It is this analysis capability that is the real barrier to the market moving, IMO. It is in reducing barriers to practicing sustainable design & analysis that we play a role. We can create the tools for analysis, but it's what you do with that information that make a design "sustainable."

Stepping off of soapbox...

You as customers have the opportunity to help drive our product directions as well by voicing your opinion on what's important to you. That is our strongest driver in product direction, I say that without any hesitation. This is why I welcome such spirited dialogs. I long for the days when I could simply post what I wanted without knowing what it would take to deliver, ignorance was bliss. That's not meant to be a knock on any of you, that's exactly what you should be doing...let us figure out the details.

Now that you know where I come from on the subject, I'll go over what this Revit/IES integration is that you speak of...

Well, not yet....It's important to point out that there exists today a lot of capabilities for leveraging building information models in your analysis applications. In the non-structural world this is predominantly in the form of gbXML. This open file format is designed to be used to communicate building geometries as well as certain properties of that building. The gbXML file represents a building's geometry by breaking it down into spaces, each space consisting of surfaces that make up it's geometry's seperate surfaces, which in turn, contain openings like windows and doors. These spaces and surfaces contain attributes to be used in analysis. In Revit the geometry of the rooms in the building, and their bounding elements, are the source for the gbXML output. This is done for many reasons, but mainly because it matches up nicely with the gbXML schema.

The gbXML export from Revit works quite well today, when the building model is set up properly. Room volumes must be computed, rooms must be adjacent for walls to be set as interior, bounding elements must be set as boundable, rooms must extend up to the floor above or have another room to represent the plenum space...Like many other design tasks involved in complex buildings, it's a bit of a science and learning is required. I This is a subject that I could go into even more length on, but I'm already way beyond the my intended scope. The point is, Revit works a certain way when it generates an analysis model, and if you don't understand how it works, it's not gonna work for you. **** in....**** out, as one of my college professors loved to say.

This gbXML capability significantly reduces the time it takes to carry out various analysis tasks because the building geometry does not need to be re-created. This alone is cool functionality.

But, I did say something about IES didn't I? Well, now I'll get to the meat and potatoes. IES has software called the Virtual Environment, or the <VE>. This is an incredibly robust software package capable of carrying out many different types of building analyses. We've chosen to partner with them to further develop the analysis capabilities of Revit. This manifests itself in a couple ways.

First, we've developed a direct link between the upcoming release of Revit MEP (formerly Revit Systems) and the <VE>. This allows for a more robust transfer of building data directly into the <VE> for analysis. There is no importing or exporting. Things like shading surfaces, window and door locations, room occupancies, internal loads, wall constructions, and room types are also transferred along the way. It is important to note that some of this information is also added to a gbXML file generated from Revit.

Second, we’ve utilized one of the <VE>’s analysis modules directly within Revit MEP for native Heating and Cooling load analysis. This is possible because the vast majority of the inputs to the analysis already exists on the rooms within the Revit model, although they are only visible within Revit MEP. This capability allows for quick evaluation of changes on the Heating and Cooling energy requirements for a building.

There’s also additional stuff in the works, but I can’t talk about it at this point. It is important to know that at this point the only <VE> capability native to Revit is the Heating and Cooling load analysis capability. Broad statements that the <VE> is inside Revit aren’t true, sounds cool though huh?

Well, I had hoped to cover more than this, but time, and my sanity, dictates that I should stop here for now. I hope this provides some insight for you on the topic. I can’t guarantee I can answer your questions about everything, and I certainly can’t talk about future directions, but it doesn’t hurt to ask.


Cheers,

Kyle B

[Andre Baros]

Kyle,
Thank you very much for taking the time to add so much information to the discussion. I understand how little you are allowed to say due to competition, etc. and I'm very grateful for each word.

That said. Will a day EVER come that some of this analysis is actually a part of Revit (the Original Revit Architecture) which many of us have been using for years? I'm only partly bitter because I've met several members of the development team and I know how dedicated everyone is, but seeing real features role out for MEP and only getting repairs for Revit building does beg the question... do I have to keep buying new programs for additional functionality.

We're working with many talented engineers right now on projects, some of whom are using Revit MEP, but so many day to day decisions would benefit from basic analysis... daylight (with numbers), convection and air flow, simply being able to track R values as part of a wall assembly or U values as a property of a material, etc.

To stay on the hopeful side, can you speak at all about the future integration of these features across the platforms. Will there ever be a day when I can at least enter the energy properties of my building in Revit Architecture before it disappears for analysis? Without saying too much, will the features you've already spoken of, ever make it to Revit Architecture?

[kyle.bernhardt]

Andre,
Oh so tempting, I'd love to answer a lot of that...but I'd probably lose my job, and I really like my job.

I'll put it this way. Product directions, and thus the features that we develop, are driven by the requirements of the market for each product. You in the community are that market. If the architectural community stands up and says "We want the IES integration and analysis capabilities A, B, and C, and we don't want anything else until we get it" (huge exaggeration to make a point), then we would go ahead and do it as a top priority. The reality is that beyond things such as these sorts of analysis capabilities, the Revit Platform, and it's vertical products can always do things better to support traditional design workflows, performance, usability, user productivity, scalability, content, construction documents, quality, and many other things, you get the idea. Different people want different things, different companies want different things, and different countries want different things. Point is, there are many factors and considerations that need to be taken into account when choosing product direction and the features, and the entire market as a whole must be taken into account. Just a little insight into the process we go through in setting direction, makes for some fun meetings and very difficult decisions.

Does that mean that I'm saying "no, it's not gonna be in Revit Architecture"? No, I'm not saying that. I actually don't have much impact on that anyways. What I'm saying is that if the market wants it, and it will significantly benefit our customers, we'll probably deliver it. Our heads are not in the sand.

Obviously, the MEP product market is traditionally more involved in analysis, and this drives our product direction, hence the IES link. We will continue to develop the program to better meet the needs of MEP engineers around the world. What you see in the product today is our best effort to meet those needs. Does that mean that there is a benefit to architects along the way? One could certainly make the case. We in the different Revit Product Teams don’t make decisions in a void and will take into consideration cross-discipline opportunities that can help make the Revit platform the hands-down best solution for all disciplines.

As for analysis, here’s my take. THIS IS IN NO WAY A STATEMENT ON OUR PRODUCT DIRECTION, just my opinion as a Mechanical Engineer and technology dork. It's logical that data required for analysis reside on the elements that exist in the building model itself, and not in some wizard, that’s part of the whole BIM concept. You make a change to a wall thickness, that changes the resulting U value. It’s logical that the data required for analysis be entered by the user best suited for handling that data. If it’s a wall construction, that’s the architect; the supply air temperature, that’s the engineer. It’s logical that if the data exists in the building model in the first place, that one doesn’t need to re-create that data to carry out analysis. You shouldn’t need to locate light fixtures inside your analysis model for point-to-point lighting analysis when they already exist in the model. It’s logical that elements be intelligent, and be able to accurately represent their real-world cousins. A wall should know it’s U value according to what it’s made of, an air handler should know it’s carbon footprint to manufacture. In order to drastically reduce the barriers to completing analysis, and in the process change the way we think about designing buildings, we’ve got to do these things, and do them well.

Once again, stepping off my soapbox....

Even with that being my feelings on the topic, that doesn’t mean that I’ll try to go ahead and make that a reality tomorrow, I still need to deliver what the market wants, what benefits them the most and gets them to use our software. I think I covered that topic in great detail above.

I know I haven’t really answered your question directly, I’m pretty sure you didn’t expect me to anyways, but hopefully that helps you answer it by yourself.

Cheers,

Kyle B

[ron.sanpedro]

Kyle said "Obviously, the MEP product market is traditionally more involved in analysis, and this drives our product direction, hence the IES link."

Kyle, thanks for the info, and I will add this. Yes, the MEP Engineer has traditionally been when this kind of analysis gets done. And we have done a lot of really BAD building this way, because all you can really do is validate what you have, good or bad. The analysis can not inform the design in any fundamental way when it is being done in DD. It must be a part of early SD, and even PD, where you might experiment with really rough energy loads and material usage based on nothing more than possible overall form, one square tower, two rectangular towers, etc.
If we are to ever get to things like true carbon neutrality, it will REQUIRE that architects start doing this analysis very early on. So instead of Autodesk taking the "When the market demands it" approach, I would like to see Autodesk step up and walk the walk that got talked at AU. I want to see good green tools put in the product NOW, and Autodesk saying to the profession "We gave you the tool, now lets see you use it!" We don't have time to wait around for enough people to figure out they need it, then ask for it, then wait to get it. That mentality is why we are where we are now, and Autodesk needs to be part of the solution by changing some corporate behaviors. Sustainability seems like a good place to start. Might even make for good investor relations. And it will certainly make for a better world.

Best,
Gordon