The Building Regulations set minimum energy performance standards for new homes and non-domestic buildings. They are deliberately couched in performance terms and do not prescribe the technologies, materials or fuels to be used. For example, many roofs are not suitable for solar photovoltaic (PV) panels because of roof design, age, strength, or building orientation. It would therefore be implausible for a blanket requirement to deploy solar PV on every roof.
We are, however, planning to consult later this year on an uplift to the Building Regulations energy efficiency standards where there are safe, practical, cost-effective, and affordable opportunities to do so.