Where an existing building has been stripped of services such as heating, lighting or say Domestic Hot Water (DHW) then all non-domestic EPC assessors are required to make assumptions relating to building services.
The assumptions that the assessor is required to make for the EPC need to be the worst case scenario and the recommendations made in the Recommendation report will outline how the EPC could be fitted out to improve the rating.
Lighting - Tungsten. SBEM lighting convention 7.05 states "If no light fittings are observed or have been stripped out or the lamp type cannot be ascertained the default selection of tungsten lamps must be made."
Domestic Hot Water (DHW) - Direct electric instantaneous with a system efficiency of 0.5. SBEM hot water convention 6.06 states "where details of the HWS are unavailable or there is no system then the HWS must be entered as an instantaneous system with no storage with a seasonal efficieny of 50%. Where the fuel type can be readily determined then the appropriate fuel type must be used otherwise 'grid electric' must be assumed." Therefore where a DHW system has been stripped out then a instantaneous diect electric system with 50% (rather than the usual 100%) efficiency must be used.
For more imformation on why buildings heated with direct electric generally produce a poor EPC result see our article Carbon Emissions from Electricity Production.
Carrying out an EPC for a shell & core unit is different from a existing building with no services. A building that has been occupied but has its services stripped is NOT Shell and core and worst case scenarios should be applied. Shell and Core EPCs are still considered newly constructed buildings. On discussion with Scottish Building Standards we understand that buildings that are not subject to a continuing requirement are not considered shell & core.
If a building is offered to the market for sale or let as a shell for specific fit-out work by the incoming occupier, the developer should demonstrate via the design-stage TER/BER submission how the building shell as offered could meet the energy efficiency requirements. For those parts of the building where certain systems are not installed at the point the building is to be offered to the market, the model that is used to derive the BER will have to assume efficiencies for those services that will be installed as part of the first fit-out work.
The assumed specification will identify which services have not been provided in the base build, and the efficiency values assumed for each such system.
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