Area boundaries are no longer functional

[wildcat_714]

Anyone who looks at Wes's file will get it right away.

Definitely agree with this. It made it very clear and more than a little depressing.
p-

[Tom Dorner]

This is completely unacceptable and must be addressed ASAP.

We use Revit area plans for lease area calculations and the area Revit calculates is written into the leases of the property management firm we do 90% of our business with. We and our client rely on accurate area calculations. If there are errors on our part (or the software we use is inaccurate) we get charged the area differential. This means that we as architects end up paying for the error over the life of the lease. ($20/SF per year for 5-20 years)

I'm as big of supporter of Revit as anyone, but this is a deal breaker for our use of Revit for area calculations.

As for the statement that BOMA allows for a 2% deviation, it is from the preface of the 1996 version of BOMA. It states that the original area re-measured by a different party is deemed accurate if the difference is less than 2%.

This is not the same as the area can vary by 2% once the area measurement has been deemed accurate. In practical terms, property management firms expect that once the area is calculated for a building that we get each floor to close out by 1RSF per tenant. The 1 RSF they give us is for rounding.

We have many buildings where we end up with little slivers and slices some as narrow as a few inches in tenant suites. After 20 years of remodeling, that is what you have to deal with. For Revit to ignore these areas will end up costing us a fortune, put us out of business and me out of a job.

[BWG]

This is extremely bad news. We have already sent out some projects that could end up costing us if we have any of these conditions, which it looks like we will. I have had this happen once before using another program; hence, switched to revit.

[Wes Macaulay]

I wouldn't worry about it too much, folks -- I'm sure the Factory will fix this soon. I'm glad we've got developers in such close contact to us who can turn that big Adesk ship around on a dime.

[phyllisr]

This thread is getting pretty long as is my post so unless you have nothing better to do, skip it. Unless you are a spreadsheet nerd like me. I am confident Autodesk will find a solution to something this critical. Clearly, the discussion about accuracy pushed a lot of buttons, some related to BOMA and some not. To explain how critical this issue is for those of us deep into BOMA calculations done correctly based on the ANSI/BOMA Z65.1-1996, it is not about the 2% rule or the real estate market or accuracy. For those who migrated to Revit a long time ago, remember the 8 decimal display in AutoCAD means that an AEC object (a wall, for example) with an angle of 0.00000000234 and one that is actually 0 will not behave correctly. We went crazy trying to figure out why.

What matters is not whether my Revit model shows 300,000 SF or 300,006 SF but that I can justify one or the other. Any changes must correctly result in the same total as leases change. It is no different than a paper copy that you measure by hand. You may not be able to measure anything finer than one inch but you can base your measurements on an assumption that remains consistent. If you assume the building is 100' x 100', the SF remains at 10,000 even if the building is actually 100'-1" x 99'-11".

The accuracy problem with the Revit areas and rooms is that changes will not result in a consistent set of assumptions, not that we or the owner care specifically about this inch or that. Attached is a PDF with the tenant and client name removed of a BOMA calculation that I have been maintaining for a client for 18 years beginning with the 1980 standard that we modified to do something similar to what the 1996 standard now does.

I would challenge anyone to maintain a spreadsheet with this level of complexity without mining consistent information from the model. In the best of circumstances, getting column 5 and 20 to equal is a nightmare. This was difficult in AutoCAD V9, easier in ADT, and easier still in Revit. It's not the actual constructed accuracy, it's reliable assumptions and consistency.

We are deploying 9.0 soon and now that we know it's a problem, we will be aware and find a short term work-around until Autodesk fixes this. Perhaps Autodesk could give us a gift at the same time and correct the spelling for the dimension parameter in the ADA parking stall family. ACCESSIBLE instead of ACCESIBLE.

[Wes Macaulay]

I've been thinking more about how Area Plans now need an area object -- you can't just create area boundaries and be done with it: like rooms you have to add the 3D area object first.

This is a pain -- more work for us to add the 3D area object -- but I suppose it's good in that during the prelim phases of a project you can use area plans for space planning and have volumes to hand off to HVAC for calculating heat loading based on the volume of the spaces, etc.

What do you think about this?

Also be sure to vote on the poll with this thread since I have a support request in to change area boundaries so that areas bounded with segments less than 1' long are calculated correctly, and included in Revit's area plan calculations. The Factory needs to see what our needs are.

[phyllisr]

What do you think about this?

As long as you made the suggestion, perhaps an object approach would solve an earlier problem I had with sections and a request for an "area plan" in section view.

http://forums.augi.com/show thread.P...Elevation+Area

This is a great idea and I fully support this approach. Even if I do not get my section view solution.

[Chad Smith]

I read this whole thread before looking at Wes' example file, and Damn!! that has to be fixed.
As the designer in the office, all of my drawings are costed off and are to the clients requirements. I'm a little concerned about my projects I've done in 9.0 now.

[MRV]

This could be bad... real bad, depending on the situation.

So if I add a 10" wide wingwall projecting out from a house slab, in theory Revit will report no change in sq.ft. of slab? Somebody better get the factory on this asap!

Michael Vaughn

[tamas]

So if I add a 10" wide wingwall projecting out from a house slab, in theory Revit will report no change in sq.ft. of slab? Somebody better get the factory on this asap!

Michael Vaughn

Michael,

I think what you describe here can be checked in about 1 minute. Have you tried it?

We have done extensive testing on 9.0 and found these cases occurring rather infrequently.

Tamas