Old building pursuing GBOM - CIR for an exception on EA1

Having done some word-eating in my day around EAc1, I know where you are coming from. A couple of thoughts that may be helpful - My experience is that the USGBC/GBCI and Energy Star are very closely aligned on the issue of historic buildings. They generally conclude that the age of a building is not relevant to its energy efficiency rating. Obviously, age affects energy efficiency itself, but Energy Star (and by extension, LEED) are not designed to compare buildings adjusted for age - they just compare buildings based on space uses. So frankly I'm not optimistic for you on that point. On the space use issue, I think you've hit on a challenging aspect of Energy Star, which is allocating common spaces to various space uses in the building. And here I think you are right to take a common sense approach - if a given corridor serves only assembly spaces, it should be included in that space use. On the other hand, if it serves both assembly and office, you might use a square-foot weighted average to distribute the corridor SF between those two space types. Hope that helps a bit.

Hi Tom, Quite often the data does not back up your assumption that an old building uses more energy than an new one. In my experience just the opposite is true. A significant improvement complinace path for this credit has been included in the draft of LEED 2012 which should be out for public comments soon. I am told that this method has also been proposed for inclusion in the pilot credits for LEED 2009 projects. So look for it there. As usual with USGBC activities it is difficult to give you any timeframes however.

I second Marcus's comments. In fact, a favorite past time is poking around the CBECS microdata, which shows pre-1950's buildings to be the most efficient age class in terms of EUI. The space classification does sound like a challenge, but even if you can reassign the corridors, you still might not be eligible for Case 2, Option 2 (or Option C for v2008). This is the path that allows historic or comparables into the benchmarking. I would recommend sitting tight as Marcus suggests to see what changes are afoot...they may help you out quite a bit.

Regarding the CBECS data and pre-1950's buildings: much of the CBECS EUI data is *site* EUI, not *source* (The dataset guidelines state that 'electricity' means 'site' unless noted otherwise.). Perhaps pre-1950's buildings use a higher average percentage of electricity for heating than newer buildings, thereby skewing the site EUI comparison. (Energy Star, of course, converts to source EUI for determining the ES rating.)