These Regulations amend the Building Regulations 2010 (S.I. 2010/2214) and the Building (Approved Inspectors etc.) Regulations 2010 (S.I. 2010/2215) as they apply in relation to England. The amendments made by these Regulations provide for a new metric for the measurement of energy efficiency in the form of the target primary energy rate and introduce new regulation for on-site electricity generation and in relation to overheating (in particular by virtue of the introduction of paragraph L2 into part L of Schedule 1 to S.I. 2010/2214, and a new Part O). Amendments are made to S.I. 2010/2215 in consequence of these changes.