I am trying to undertake the assessment of EAp2 and EA1 energy credits for a building in central London. Its about 40 floors but the project scope is to renovate only 3 floors. None of the landlords base building systems are being changed and not all would be compliant with ASHRAE 90.1 2007 as the building is about 15 years old. Am i correct in that the calculations and % improvement should just be demonstated for the tenant (and project scope) and if so do i still need to provide details of the base build in terms of calculations or is a narrative description sufficient with the calculations for the tenant space demonstrating compliance.

Also if anyone has come across a different approach for buildings in the UK please respond, for now though we are using ASHRAE approach.

thank you