Electrical-Architectural coordination

[damon.sidel]

Despite my many years using Revit, I have managed to be on many projects where consultants don't use Revit. Structure, yes. MEP, no.

The short question: what are the mechanics of coordinating electrical?

The slightly longer question/musing: The architectural model (our model), contains all the walls and ceilings in/on which the light fixtures, receptacles, exit signs, etc. are placed. For this project, we have a lighting consultant, so it gets even more circuitous. The lighting consultant did the lighting design as hand mark-ups of our RCPs. I then added all the lighting fixtures to our model and sent it to our electrical engineer. I got back PDFs of his sheets and a Revit model. OK, not bad, but... The Revit model has all the light fixtures I created, plus all the receptacles and exit signs, panels and equipment, none of the hosted stuff is hosted. Looking in 3d, everything is just floating in space.

How does the back-and-forth of coordination work from here on out? I've already redesigned some of my lighting design, adding and modifying fixtures.

To add to my confusion of work flow, the electrical engineer will only design in ACAD, so I reluctantly agreed to send him DWG backgrounds. He does his work, then sends it to a consultant to model in Revit. That's a huge waste of time and resources.

If I'm modeling light fixtures and my model has all the ceilings and walls, how should we organize the electrical model?

[tbodor]

These are all good questions. Your feeling some of my pain as I'm on the M&P side of things and I use Revit and most of our subs are still in ACAD. Good communication can help to ease some of this.

First off there are issues with items hosting to walls thru the link. Doesn't like to do it most of the time. If I have a wall hosted item I have to create a "dummy" wall on my end and hide it afterwards. I've had success with ceiling items though.

The other big issue when we can link items is once an item is placed, as long as the Archy doesn't delete the host, the items will follow. Ceilings move my air terminals move. If the item is deleted, unfortunately most of the time, your items un-host and float in no mans land. You have to go back and re-host them. This makes the coordination part kind of painful and leads us to use "face based" families instead of hosted ones.

I agree on your comment also that it is a waste of time and resources but that is the world we live in right now. That will change as more engineers start using Revit.

[david_peterson]

Most of the MEP guys I've been working with have made the switch to face based objects and not wall or ceiling hosted. At least that way they when a wall or ceiling gets deleted, the objects (and more importantly the circuits/systems) don't get deleted.
On the Arch side we've just bitten the bullet and said we're going to own the location of the fixtures and the MEP guys can copy monitor or create their own.

[damon.sidel]

If I have a wall hosted item I have to create a "dummy" wall on my end and hide it afterwards. I've had success with ceiling items though.

Yuck!

I agree on your comment also that it is a waste of time and resources but that is the world we live in right now.

Can you explain what you would want to happen in an ideal world?

On the Arch side we've just bitten the bullet and said we're going to own the location of the fixtures and the MEP guys can copy monitor or create their own.

Boo! What a waste of time and effort. The copy-monitor idea is at least a little interesting.

How did my consultant get ceiling and wall hosted families to hang around without walls or ceilings? Everything shows up un-hosted and nothing got deleted.

[david_peterson]

Face Based objects won't get deleted when the hosting face is removed.
You could also host them to a reference plane in theory.
My issue is I've never had a MEP group keep up with all the changes. If we don't place them, our ceilings never look coordinated. Most MEPs will place them correct the first time, but won't make minor adjustments when walls or ceilings make slight adjustments.
I've never gotten them to model things in the exact location where we want them.

[damon.sidel]

I've never gotten them to model things in the exact location where we want them.

All these responses so far are not painting a happy picture of the current state of affairs.

What about strategies that might work better?

[david_peterson]

If you get into a IPD project, things will work as they have to. The issue is most contracts I've seen state that the MEP drawings and models are for Design Intent Only. So the MEP groups only need to be able to prove that their design could work. They don't actually have to fully coordinate it to a "Clash Free" Level of Development. They only need to provide design intent. Many of the contractors don't need a model that shows where ever pipe is routed since they tend to want to re-route them anyway. Plus hangers and such aren't always considered in the design model as that gets to the "Means and Methods". Contracts seem to only want main runs and valve bank locations as those are usually prescribed by the owner to the design team.

Next you need to consider that projects on the construction side may be run differently. In the "First Come, First Serve" method, it's the last guy that has the hardest time placing his stuff. If you design a set of systems to be installed in only one order, the contractor may not want to follow that method.

Basically it boils down to this. At the end of the day, contractors never want to adjust or modify a design model from the Arch team or the Structural team, and the MEP models are used only as a guide. Since the outlet need to be placed on a stud (which generally aren't modeled by the design team) they will be in slightly different locations in the field anyway.
From an Arch stand point, if there's something you want in a specific location, it's easier for you to model it and dimension it and have the MEP teams play follow the leader. "If you build it, they will come" train of thought. In a perfect world, the MEP teams would update everything and make all of those small adjustments but that requires the Arch model to be locked down for a longer period of time (ie you can't move anything) which conflicts with the schedule.

[damon.sidel]

David, thank you for your thoughtful response.

It seems like I shouldn't be pushing for much more than I've received, then. When it comes to architectural modifications, such as adding, moving, or modifying light fixtures, I just do it in my model and send it to the electrical engineer to (hopefully) update. How they get there is their problem.

I will plan on that methodology for now. Thanks!

[david_peterson]

I did have one project where we were promised by the MEP group that we only needed to use place holders for and they would update their model so we could just show their fixtures.
With about 2 weeks to go before the deadline it became very apparent that we were in trouble. Nothing lined up, fixtures were in the ceiling, but cutting the grid. Nothing was coordinated. We had to go thru and replace all of our placeholders with the actual fixture and turn off all of the MEP services.
I knew it was going to happen, but it took this kind of a result to get our PMs to see the light. If you care about where it's placed, place it yourself and then just make sure you have the right quantity. I've got pages things we asked them to move and adjust that they said they were going to coordinate. It's been almost 18 mths, we're 9 mths into construction and I still can't cross anything off that list. Best expectation is that they get close with fixture location and they spend their time coordinating things above the ceiling so they actually fit. It's never good when you need to go back to the owner and tell them they're stuck with 7'-6" ceiling heights in a new facility.

[DNRodriguez]

I work inside of an A-E firm and we (Electrical) place all the lights. We are typically also required to run lighting calculations since we do many government projects and we use the ElumTools Add-In which forces us to properly place them in the model. Where you are working with outside consultants, it becomes even more critical to have a BIM Project Execution Plan (PxP). This would detail what your expectations are for what and how things are placed in the model and the PxP can be used as a contractual document that can be enforced. It would also detail how and when the model is exchanged between consultants so that everyone is on the same page as to when they are supposed to receive the latest model. A PxP is many times not used for small projects, but it really should be a part of every project.