Ceilings & linked files

[LP Design]

Hello all,

What is your process for coordinating architectural RCP vs. mechanical & electrical linked models?

The first problem I am running into is where diffusers and lights do not cut the ceiling since it is in a linked file. Secondly there are issues regarding some of the MEP families that come in poorly modeled or with flow arrows that won't turn off, or even as symbolic lines only. It has gotten so bad on some of our projects that we have actually added our own set of lighting and mechanical fixtures and hid the linked model entirely. Not very BIM.

I recently talked to another BIM manager who said their firm has completely transferred the ceiling to the MEP model to alleviate some of these issues. I am very curious to hear what methods you use.

Thanks in advance,
-LP

[sbrown]

You need to talk to your MEP consultants about their families, you pay them, so they need to use your families or at least your specs. We ask them to add a masking region to all their families so they hide the grid or hatch in our ceilings. Then only in rooms that we plan to render do we add holes in the ceiling. Many times we will provide the decorative lighting. One other option that I like is to place the lights in the arch model, then the elec. just places the Jbox in theirs. That way I can dimension and move the lights and grids at will and they basically connect to it. You really have to have an up front discussion with your consultants, they have to be prepared for you to tell them to move each item slightly this way and that. So if you don't want to coordinate then you need to put your own in.

[LP Design]

Thanks for the response, Scott.

Are there any contract/fee issues when you host the lighting fixtures in the architectural model? As I mentioned, we have had to do it in the past, but it has always been an unfortunate (and usually last minute) time-expense that nobody gets compensated for. On the other hand, if you have a discussion up front with the electrical engineers and explain that you will do the lighting layout yourself, doesn't that add to your scope and reduce theirs? What about selection of fixtures? Lighting load calculations? Photometrics? Have you ever had to place diffusers (and similar) in the arch model and have the HVAC engineer connect to it similar to the J-box example?

[jsteinhauer]

LP,

This maybe of some help to you. We have decided to create Mechanical & Electrical coordination families. These are nothing more than face based families with a void & detail lines on a 'COORDINATION' subcategory with Red line colors. I have modified our standard families to be the same category as the element they are meant to coordinate. What these families do is allow us to place a 'Light Fixture' where we want it, cutting a hole in the ceiling & letting our MEP consultant know exactly where we want it. So, they own the real family and can turn off the subcategory from our model in their views.

Cheers,
Jeff S.

[LP Design]

Thanks Jeff,

That is almost the same thing we were doing, except we just grabbed a generic OOTB light fixture, diffuser, whatever. I had not thought about putting the dummy families on a separate category so they could be more easily turned off. Is this now SOP for your firm, or only when there are errors that need dealing with?

[jsteinhauer]

we have yet to add these to our standard library. But they have been used on several projects now, so a decision needs to be made. Either way, the coordination subcategory is a must.

Cheers,
Jeff S.

[sbrown]

Jeff,
This is a great idea. do you do the same with diffusers? I guess if you are placing these families already, why not place the lights you want? As to the question of scope. Many engineers we work with don't do lighting design, that is our responsibility allready. They just do the engineering portion. So we do the light layout anyway. ID typically is responsible for picking decorative lighting, so its best in my opinion to have the design team control the locations. The only downside is the schedules, the engineer selects the right lamps for the fixtures. so maybe we should do a design intent, then the engineers copy the fixtures into their models and we swap them out with the sub category families. My problem with it all is I need to do the renderings and visualization and engineers typically don't care what the sconce looks like and I do. So who models the fixture?

[jsteinhauer]

Hi Scott,

Yes we have Mechanical diffusers and returns as well. These are setup exactly the same as the light fixture families described above. I guess I'm lucky that our MEP firm is usually responsible for lighting design, with guidance from our ID'ers. I try to stay away from modeling light fixtures because it's like laboratory equipment, (1000's of different shapes/configurations). If it's really important to get a rendering, we'll look on our basis of design manufacturers website to see if they have models first. We do most of our renderings in 3DSMax or Catchup (Sketch-Up) anyways.