1. Use a professionally accredited assessor: ensure that you employ the services of a professionally accredited assessor, like the staff at Elmhurst Energy Consultancy, who ensure they maintain up to date knowledge on building regulations. Choosing a SAP calculation provider based purely on price can result in losing thousands later down the line, due to poor and uninformed advice.
2. Renewable technologies: there is a wide variety of renewable technologies available to house builders be that heat pumps in exchange for conventional gas or oil boilers, solar panels (either photovoltaic or solar thermal), or a variety of heat recovery systems i.e. ventilation, hot water or boiler flue gas. Investing in these technologies both future proofs your development and provides an easy remedy to ensure compliance with Part L.
3. High quality insulation: construction methods that include high quality fabric elements can reduce or even omit the need for renewable technologies. Using high quality insulation, specifically those with as low a thermal conductivity / as high a thermal resistance as possible, and reducing a property's thermal mass are the best methods to improve building fabric performance.
4. Good quality glazing: glazing with low U-Values (1.3 or lower) can have a huge improvement on the SAP score. Triple glazing can get as low as 0.5 but given their expense, this is not often seen. We usually recommend double glazing which can often be as low as 1.2. Glazing with low U-values ties into improving the properties fabric performance and are usually a first point of call when we provide advice to comply with Part L.
5. Consider the heating system: the source, distribution method and controls of a dwelling's heating system have a large impact on the SAP score. Where conventional fossil fuel boilers are being installed, mains gas almost always performs best. Radiators perform better than underfloor heating but if underfloor is preferred then ensure screed thickness is 65mm or less for greatest efficiency. Time, temperature and zone controlled heating also undoubtedly performs significantly better than any other form of control.