Multi-story Buildings

[rodneyf]

Hi All,
Our office is getting ready to start doing some big buildings (i.e Condos up to 24 storys) and was wondering can Revit do something that large? Also what is the tallest building anyone has done using Revit? Would you be willing to share some of your experiences and knowledge? Any help is a great help and would be extremely appreciated.

Thanks,

[sbrown]

Revit will say its possible to do that large of a building, I think I could do it, but I would need a very experienced revit staff. We are currently working on a 7story condo/mixed use project. and the major problem is its impossible to create a typical unit plan that you copy and mirror and rotate throughout the bldg. so weve had to abandon groups, now you might be able to figure out something with linked files, but then you couldn't schedule the info in your main project.

Its a hard call. I'd like to try it, but until groups/workset work right your in for quite a ride. I'd love to hear of someone doing this type of project successfully.

[David Conant]

Ask your reseller or Revit support for a copy of the Revit Hotel5 CD. It includes a simulated 300ksf hotel project done here at Autodesk Revit. A team of 10 people worked on the project using Revit 5.0 over the course of 5 months. The CD includes the project file, pdfs of many sheets, and a slide presentation outlining key techniques used by the production team. This should help you get a large project such as this set up and help you evaluate the best method to proceed.

[trent59822]

We're working on a 13 story remodel of assisted living to condominiums and adding a floor. It's has been a learning experience but were are getting it done.

Trent

[christopher.zoog51272]

Revit will say its possible to do that large of a building, I think I could do it, but I would need a very experienced revit staff. We are currently working on a 7story condo/mixed use project. and the major problem is its impossible to create a typical unit plan that you copy and mirror and rotate throughout the bldg. so weve had to abandon groups, now you might be able to figure out something with linked files, but then you couldn't schedule the info in your main project.

Its a hard call. I'd like to try it, but until groups/workset work right your in for quite a ride. I'd love to hear of someone doing this type of project successfully.

Scott,

You are right that "unit" groups are VERY buggy, but we've been able to work around most of the bugs. We use unit groups and worksets for all of our multi-unit projects. Today, I’m working on one of our 4 story (five with basement) 120 unit apartment building for seniors. All of the units are made up of just about a dozen different groups. However, the system is far from perfect.

You have to follow the "rules" exactly. By "rules" I mean anything that doesn't cause a weird group bug;) For example; nested groups (such as a bathroom/closet group) inside a unit group (one bedroom apartment) don't always mirror so well. Both groups as a whole will mirror fine but sometimes a door in the nested group will reverse it's swing, like a bathroom entrance door will suddenly swing out instead of "in". The way to fix this is to edit the nested group that has been mirrored NOT by first using the edit group button then using the edit group button to get to the offending nested group but rather by simply tabbing to reach the offending nested group and editing it right there. When you finish the edit all the offending mirrored nested groups will be correct. It’s as if revit keeps two different copies of the same group in it’s database (under the hood) and sometimes they don’t jive.

I know that doesn’t make sense, but it works. It’s one of those things that comes from blood sweat & tears, it’s trial and error.:roll:

Another thing is that you have to be extremely careful about what goes into the group and what doesn’t. I personally include the hallway walls and the entry doors, but I don’t include the unit demising walls. I don’t include the exterior walls or the windows, but I do place reference plane in the unit group at the centerline of the living room and one at the centerline of the bedroom. I then explicitly place the windows then align and lock them to said reference planes. This way the groups don’t contain the windows, but the groups can still control them. You have to create special families for host mounted casework so it’s not host based any more because I don’t include the demising walls in the group. I use special door families with shared parameters, so I can use a multi-category “DOOR” schedule, so I can use the filter tool because the regular door schedules can filter out specific doors (such as unit doors from common door). <sigh>The list goes on and on…….then worksets add yet another layer of complexity…..revit really needs to make this easier.

Is it worth it? Well, when I look at the alternative, which is AutoCAD 2000, then YES!! Plus, once you have good system down and a kick-*** template, you can get it going much faster. But like Scott said, having experience revit users helps.

[Alek Sutulov]

I have started 60 storey hotel late last year on release 4.5 and later on converted to 5.0.
The new tower was to sit over existing 15 storey hotel and adjacent to another existing 39 storey hotel.
I was the only one working on the project with best "budget" hardware available at the time.
Well, I was able to produce building skin of all 3 buildings, windows, roofs, floor plates, shear walls, and couple of typical floor layouts of the new tower. Existing floor layouts were to be covered by Autocad overlays.

Project was converted to Autocad after that because I felt that my hardware can't handle it efficiently any longer. Regeneration started occuring after almost every zoom, and it was lasting longer and longer. There was also a plotting bug (fixed in 5.1) which was causing 35-45min. plot generation per sheet, and I had only 4 sheets created so far. Overall, it was disasterous experience for me.

My opinion is that with hardware most of us have, you can't do full C.D. set. At the time of my adventure I was seeking some guidelines from Revit with respect to performance improvements if better hardware was used, but response was that they have no means to do it !?

Alek

[christopher.zoog51272]

Here are some pics that show what we include in groups/nested groups:

http://www.zoogdesign.com/albums/revit/group_4.sized.gif

http://www.zoogdesign.com/albums/revit/group_3.sized.gif

[overcaffeined1745]

Chris, what's the minimum hardware (processor and RAM) you'd recommend for working in a project like your 120 apartment units? (note that I said "minimum" rather than "perfect"). In this moment I'm creating my groups for a multistorey project like yours, but I'm afraid my hardware (P-III with 512MB RAM) might be too little for such task. I really -need- to finish this project with Revit, so maybe I'll need to upgrade my hardware. Any suggestion welcome!!

I thought on using linked files instead of groups (which could perhaps decrease the RAM usage and increase speed), but I read that light sources are buggy in linked files, so groups seem to be the best option.

Another related question:

I need to do detailed views of each apartment type. Do you think it's best to create each apartment type in a separate file, define its detailed views there, and later save the apartment as a group to disk (to be included in the multistorey file)? Or do you prefer to do the whole work in a single file?

I think it would be best to do it in separate files for performance reasons, but then, if I need to change a unit, I'd need to re-save the group and re-load it in the multistorey file...

[rodneyf]

I am going to ask my reseller for a copy of the Revit Hotel5 CD. Also I am going to use all of the excellent info provided here and try to setup the best template I can for such a project and will let everyone know how it all comes out.

Thanks,

[Wes Macaulay]

Hey Z, what are you doing for the hatched floor areas? A thin floor object, or a filled region?

[sbrown]

I just trained our staff on how to produce tile floors, its very easy, you place your entire floor, say its a slab on grade, then use the split face tool and paint the area with a tile material, assign a surf. pattern to the material and you can then adjust it as necessary by tabing to get one of the surf. pattern lines and move it or rotate it.

[christopher.zoog51272]

Chris, what's the minimum hardware (processor and RAM) you'd recommend for working in a project like your 120 apartment units? (note that I said "minimum" rather than "perfect"). In this moment I'm creating my groups for a multistorey project like yours, but I'm afraid my hardware (P-III with 512MB RAM) might be too little for such task. I really -need- to finish this project with Revit, so maybe I'll need to upgrade my hardware. Any suggestion welcome!!

I tell you what we use:
The slowest computer working on this project is an AMD Athlon 2200+ with a Gig of DDR Ram. All of our workstations have at least a gig a ram. I use a dual athlon MP 1900+ with 1.25 gigs of ram and a Radeon 9500 Pro 128 mb video card. Even with this hardware some areas are the project are slow to regen. We have been controlling this with worksets, etc. But as always I’d still like to see performance improved dramatically. Revit seems to love processor power, then ram. Ram really only helps when you are working on very large project, and you are getting close to maxing out your ram, so adding more really only helps when you are running out of “gas” so to speak. Right now this project chews up about 400mb of ram while I’m working on it. Upgrading the processor would be the first thing I’d do.



I thought on using linked files instead of groups (which could perhaps decrease the RAM usage and increase speed), but I read that light sources are buggy in linked files, so groups seem to be the best option.

In my limited testing, I have not had any success using linked files to create a building.




Another related question:

I need to do detailed views of each apartment type. Do you think it's best to create each apartment type in a separate file, define its detailed views there, and later save the apartment as a group to disk (to be included in the multistory file)? Or do you prefer to do the whole work in a single file?

I think it would be best to do it in separate files for performance reasons, but then, if I need to change a unit, I'd need to re-save the group and re-load it in the multistory file...

That’s a hard call, we tend to detail an apartment right in the project using a call out view. I have been toying with the idea, of building the units as separate revit files and then exporting them as a group to load into the main project. I think this may avoid some of the problems with group mirroring, and give me more control over the groups origin, which has to be exact if you are going to make changes. It seems like I am always forgetting which was the “original group” and which orientation it was at. If it was an external file, I’d always know. I’ll let you know what I find.
:D

[christopher.zoog51272]

Hey Z, what are you doing for the hatched floor areas? A thin floor object, or a filled region?

It's a thin floor object. It has to be that way if it is to be part of the group. I also use Scott B's method on non-grouped projects.

[overcaffeined1745]

The slowest computer working on this project is an AMD Athlon 2200+ with a Gig of DDR Ram. All of our workstations have at least a gig a ram. I use a dual athlon MP 1900+ with 1.25 gigs of ram and a Radeon 9500 Pro 128 mb video card. Even with this hardware some areas are the project are slow to regen. We have been controlling this with worksets, etc. But as always I’d still like to see performance improved dramatically. Revit seems to love processor power, then ram. Ram really only helps when you are working on very large project, and you are getting close to maxing out your ram, so adding more really only helps when you are running out of “gas” so to speak. Right now this project chews up about 400mb of ram while I’m working on it. Upgrading the processor would be the first thing I’d do.


OK, it seems I can try to continue with 512MB, although the P-III processor might get too slow when the project size increases. I might consider getting a fast laptop if I find that my current hardware is not enough.

Regarding using a different file for each apartment... I'm also curious about it, so I think I'll try it. I wish I don't find any serious bug there...