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The short answer is no, you don’t have to. An air source heat pump is the most efficient and sustainable heating system meaning that you are less likely to require additional renewable technologies e.g. solar PV. Using other heating systems such as gas or electric boilers is still allowed. However, it will mean that you

The standard set out in Approved Document Part L 2021 is a maximum air permeability of 8 m3 /(h·m2 ) @ 50Pa. However, the air test target will vary between different dwellings & is often lower than the maximum set out above in Part L. This is determined by the dwellings SAP Calculations. A better

The short answer is no! However, under the updated 2021 Part L Building Regulations, gas boilers must be accompanied by some form of renewable energy to meet compliance. This is most commonly solar PV. The solar PV requirement will depend on the fabric and heating specification of the dwelling. When carrying out the SAP calculations

Myth #1 – A 150mm cavity is required This is dependent on the insulation you are using. A better performing insulation will require a smaller thickness to meet compliance. For example, 90mm of a high-performance PIR board with a 10mm air gap can achieve the same results as 150mm wool insulation. Myth #2 – I