The State Legislative Building was originally built in 1927 and has not seen significant modernization since that time. It is listed on The National Register of Historic Places. As such, ASHRAE Standard 90.1-1999, Exceptions to 4.1.2.2 apply. This allows that a historic building "need not comply with these requirements otherwise applicable to such building or space that is being altered." This refers to an exception to bringing Envelope, HVAC, Service Water, Power, and Lighting Systems up to the ASHRAE Standard. We propose that in light of Exception to 4.1.2.2, the existing historic envelope and historic lighting systems become the "baseline" for our building simulation model to meet ASHRAE 90.1-1999. Because of their historic nature those building systems will remain basically unimproved. The HVAC system and some lighting in the office areas will be improved, therefore, we will not seek exception for those systems. Do you (USGBC) concur with the approach of setting the baseline of the building using the ASHRAE Exceptions where applicable?
The historical building exception in ASHRAE 90.1 (Section 4.1.2.2) allows historical buildings to meet this LEED prerequisite without documenting compliance with other specific performance requirements of 90.1. However, this exception only applies to portions of the building which are components of the historic designation, most typically the building envelope. Wholesale replacement of building mechanical or lighting systems must comply with the respective requirements of ASHRAE 90.1. This is particularly true if the project is applying for energy performance credits (EA credit 1). In such a case, the HVAC and lighting baseline performance would be determined by the alteration requirements in ASHRAE 90.1. To determine the baseline then, the project would use the existing designated historic building envelope characteristics, and any upgrade to these conditions would count toward energy performance achievement. Replacements of building HVAC and non-historic lighting fixtures would need to exceed ASHRAE 90.1 requirements for those components to achieve energy performance credits. Applicable internationally.