I've recently come across a project which is a bit difficult to describe at first, so bear with me.

The architect has taken a very large, existing metal building and divided it into 5 distinct sections. See attached for a simple drawing that might help clarify and provide a key for the descriptions below.

1) Single story lab space. Has a completely separate roof assembly with slope opposite of existing roof slope. "Attic" space between new roof and existing roof is contiguous with space 2. Some duct is routed through this attic space.

2) Unconditioned, naturally ventilated.

3) Two story office space. Similar to space 1 above, has an "attic" space which is contiguous with space 4.

4) Unconditioned, naturally ventilated.

5) Unconditioned, naturally ventilated "circulation spine." Not contiguous with spaces 2 and 4.

The way I see it, there are a couple different ways to model this, but I don't know how eQuest will treat them and which would be suitable. I am modeling in an effort to achieve LEED EAc1 credits, so your opinions on which the LEED reviewers might accept would also be much appreciated.

1) Build single large shell representing existing metal building and place smaller shells inside this shell. Not really sure if this level of complexity is necessary, or even if eQuest would know what to do with it. Larger shell would probably be single zone, and modeled as unconditioned. Does eQuest have provisions for natural ventilation I could implement? How would I model the walls which are shared by the outer shell and inner conditioned shells? Would the wizard recognize the coincident boundaries and model only one wall?

2) Build conditioned spaces (spaces 1 and 3) as separate shells and place a large shade structure over both shells which is geometrically similar to the existing metal building. This would be easier from a modeling perspective, and at first glance, seems thermodynamically similar enough. Since the unconditioned spaces are naturally ventilated, is it safe to assume that the conditions would be similar enough to the outdoor conditions that this would work, even though the existing metal building is insulated? I suppose this would depend largely on the efficacy of the natural ventilation, but predicting this seems prohibitively difficult.

Thoughts? Anyone run into this before and pushed it through LEED?

Cole Hudson, E.I.T.