My company just recently purchased IES VE for load calculations and energy modelling. I won't really need to touch the actual energy modelling side of it, but I'd really appreciate any tips, resources, or experiences other have with preparing and moving an analytical model from Revit to the Virtual Environment. A little background: we are not architects, we are a strictly HVAC firm. We get the building after the architects have done most of their design. The purpose of the energy model is really to show compliance with certain energy targets, not to inform decisions about the building itself, only the systems. I have read up on Autodesk and IES's documentation for energy modeling, but I haven't has much success in getting as clean of results as they describe.

My boss, who is very enamored with the "I" in BIM, would really like to push detailed thermal properties information with the model. I know it is possible, but I have a tenuous-at-best foundation with that sort of thing. Has anyone taken advantage of this functionality? Did it work well? How did you manage the data within Revit? I don't trust that the material properties that the architect uses are correct. However, I worry about reconstructing what the architect has specified, and not having an easy way to update it when changes are made. Another thing he'd like to push is lighting and power loads. We don't do the electrical design and it seems like these sorts of values have to be changed from the default space type settings every time, which means going through dialog boxes, not just the properties palette. Is that the only way? How have you handled this?

Another big issue I see is managing spaces in a way that will transfer data to the gbXML. I'd prefer to use the architect's model, but I often find spaces placed in small spots that really have no business hosting a space. Conversely, everything I've read stresses filling the complete building volume with spaces. How have you managed these small spaces, or other larger void spaces, in a way that clearly segregates them from the main spaces we're actually interested in? Do you use the default space types, or do you create your own? Do you model ceiling plenum spaces? If so, how do you handle varied ceiling heights (or stepped ceilings)?

I have more questions than answers, and it has made it difficult to explain what is and isn't possible, and what is or isn't practical to my superiors. And, of course, all of this has to get filled in around actual modeling for CDs! Any help/suggestions/insights/etc. you have to give is most appreciated.