# Revit and Consulting



## pelaw (Jul 27, 2010)

Revit is cool. I get that. I also get that Revit allows construction people to see what's going on in space.

But what happened to the whole: Engineering plans are diagramatic and do not show every detail of construction?

I say Revit is not for engineers. Let the engineers work in 2d for permitting, and have construction people build models for their own convenience, if they want to waste their dime.


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## IlPadrino (Jul 27, 2010)

Note sure where to start... Building Information Models (BIMs) provide for lots of uses beyond "construction people".


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## Supe (Jul 27, 2010)

Us construction people sure wish you office guys would use collision detection for pipe supports and floor penetrations! ldman:


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## MGX (Jul 27, 2010)

Supe said:


> Us construction people sure wish you office guys would use collision detection for pipe supports and floor penetrations! ldman:


We do (when specified in the contract!).


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## IlPadrino (Jul 27, 2010)

Supe said:


> Us construction people sure wish you office guys would use collision detection for pipe supports and floor penetrations! ldman:


Getting MEP distribution lines built off-site and then "plugged in" on the jobsite sure speeds up things!


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## Supe (Jul 27, 2010)

IlPadrino said:


> Supe said:
> 
> 
> > Us construction people sure wish you office guys would use collision detection for pipe supports and floor penetrations! ldman:
> ...


We have separate models for the turbine and boiler buildings, designed using two different software packages, with as many as 5 vendors piping in there, and if it's not ours, it's not labeled!


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## Road Guy (Jul 27, 2010)

:dunno:


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## MGX (Jul 27, 2010)

Supe said:


> IlPadrino said:
> 
> 
> > Supe said:
> ...


Hopefully this will all be worked out in the next few years. We have people running Revit, AutoCAd, Canned AutoCAD software and other programs all wanting to be crammed into Navisworks.

Origin, scale, object enablers, etc are all out of whack (at least where I am) but when the dust settles things will/should be much easier and ultimate (what's installed) design improved.


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## wilheldp_PE (Jul 27, 2010)

Revit and other BIM models definitely have their uses in the MEP world, but they sure do muck up the design time-line. With AutoCAD and other "dumb" CAD packages, the architects can bang out a base model early on, and MEP can get their basic design done for 35% or earlier submittals. With BIM, you have to have a shit-load of information to get a basic drawing out the door. If you don't have that information available up front, then you have to "fake it", then go back and add the information later which essentially involves re-doing the whole design. Basically, you duplicate effort. The customers really need a lot more conditioning on how to handle BIM-designed projects because it is really front-loaded. They need to be very far along in their planning process before they hire a firm to do a BIM model whereas in the past, they could plan the building while the A/E firm was doing preliminary design work.

I experienced this transition and disconnect in my 1.5 years in the A/E world, and developed a bad taste for BIM modeling because of it.


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## MGX (Jul 27, 2010)

Its always fun when someone's object enablers don't work on another platform and the result is an undetected collision happening hundreds of times etc...

I'm not bitter but see this stage as the technology's infancy and willing to go through some teething pains.

Similar pains were experienced when we moved from drafting tables to computer desktops.


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## wilheldp_PE (Jul 28, 2010)

I'm also a little bitter because my A/E firm was an early adopter of Revit, and our local Autodesk distributor greatly exaggerated the level of refinement that Revit MEP had attained. Autodesk bought Revit from a start-up company that wrote it. They put a lot of work in on Revit Architecture to refine it and integrate it with AutoCAD. The problem is that they treated Revit MEP as an afterthought, so its development lagged way behind Arch. The other problem is that my old firm was run by architects, so they just thought we were bitching to hear ourselves bitch when we told them how much Revit sucked. Turns out, they thought the MEP version was as refined as the Arch version, which wasn't the case.


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## HerrKaLeun (Jul 30, 2010)

Sure Revit is in its infancy now... but I also think all future development resources will go from CAD to REVIT.

I bought Revit MEP this year and will start using it soon for HVAC projects. I haven't tried it out yet (and the book to explain it all won't be published before November), but I think the ability to do piping and duct calculations in Revit is fantastic and potentially saves time and reduces change orders.

I'm not sure if the load calculations are worth anything, but will stick to TRACE.

I adapted to using CAD MEP over the years and tried to do things in 3-D. but CAD is so 20th century, that i figured with the effort to learn CAD in 3-D I might as well learn Revit. CAD can do collision detection too... but how difficult. CAD is a drawing software, but Revit has the potential to actually be a design software. And the ability to only have one file and not dozens of referenced dwg files for views, sheets etc. is interesting.

I wish they would implement a decent lighting calculation. If I could do lighting calculations I could ditch my lighting software and had an easier time.

One thing to consider, you want a state-of the art computer. 8 GB recommended. If IT departments had already arrived int eh 21st century,t hat would be great...


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## wilheldp_PE (Jul 30, 2010)

HerrKaLeun said:


> I wish they would implement a decent lighting calculation. If I could do lighting calculations I could ditch my lighting software and had an easier time.


The lighting calculations are nice, but their accuracy is entirely dependent upon the information you give it. If you assign a fixture the wrong .ies file, or if your placement is slightly off, your lighting calcs will be wrong, and no error message will be given to alert you to that fact. Plus, I don't think you are able to run lighting calcs until every fixture is installed and circuited using the Revit tools...which is kinda tedious.


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## HerrKaLeun (Jul 30, 2010)

wilheldp_PE said:


> The lighting calculations are nice, but their accuracy is entirely dependent upon the information you give it. If you assign a fixture the wrong .ies file, or if your placement is slightly off, your lighting calcs will be wrong, and no error message will be given to alert you to that fact. Plus, I don't think you are able to run lighting calcs until every fixture is installed and circuited using the Revit tools...which is kinda tedious.


From what I read Revit does NOT do a point-to-point calculation but rather has a calculation based on the lumen-method. Since i haven't tried it I can't tell if it really matters since I have enough experience to illuminate the necessary work areas and look more for a confirmation of the average fc-numbers. I also hope they will implement a point-to-point method.

Currently I use Visual. I had looked into DIAL which has much more features... but realistically I never enter all those data.

Obviously the best software won't be accurate since I'm too lazy to enter all information. I rather use default estimated values for reflectance (like shop walls always have low reflectance since they get dirty and the walls are covered in tools...). And the usage may change in the future.

Anyway, I still hope to get that done int he same software I draw in. Lighting is pretty easy to calculate from a computational point of view.


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## pelaw (Aug 2, 2010)

BIM is driven by movement towards Design/Build. If you are contracting for design/build, you will want to have BIM presentation to owner, and ability to eliminate all design errors since you are on the hook for those. (timeline to completion is negotiable, but liability is not.)


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