Good day to all..

Working on modeling an existing building per 90.1 for LEED certification
and can not find clear answers in the standard or users guide- and seeking
of the advise of the Bidg-Sim community-
The building is basically a shell- the 6 inch tilt up concrete walls and
concrete floor are the only things remaining un-changed. The building is
installing new HVAC systems, a new roof, a new lighting systems, new
skylights, new doors, new windows and insulating the existing walls. The
space is 35,000 square feet, and beside another building. The building
owners bought out their former neighbor and are expanding into their space,
the space shares a wall with their current space.

1. Adiabatic wall- Should it be Modeled with an adiabatic wall
separating the "two" buildings (that are actually one building with a
separating wall and separate address), or should the "other building" not
seeking LEED certification be included in the model?
2. Rotated average baseline- This is an existing building and
orientation is set, so is this procedure still necessary or required by
90.1/LEED
3. Baseline Constructions- Should the baseline reflect the walls as they
where before renovation (Un insulated tilt up concrete walls/R-5 roof
deck?) or should it use the ASHRAE light weight constructions with 2007
insulation for the climate, or should it use the actual constructions but
add ASHRAE 2007 insulation?
4. The HVAC system is a CAV, with convective natural gas heating and and
DX cooling- roof top units, the baseline system for this should be system #
5 PVAV- or should the baseline HVAC system be what ever system was in the
building before the renovation?

An advanced thank you goes out to all that respond-

*Jeremiah D. Crossett*