http://www.legislation.gov.uk/id/uksi/2021/1391

PART 2Amendment of the Building Regulations

Amendment of Schedule 1 to the Building Regulations11

In Schedule 1 (requirements)—

a

in entry L1, in paragraph (b)(i), after “are energy efficient” insert “to a reasonable standard”;

b

after entry L1 insert—

On-site generation of electricity
L2
Where a system for on-site electricity generation is installed—
(a) reasonable provision must be made to ensure that—
(i) the system and its electrical output are appropriately sized for the site and available infrastructure;
(ii) the system has effective controls; and
(b) it must be commissioned by testing and adjusting as necessary to ensure that it produces the maximum electricity that is reasonable in the circumstances.

c

after entry N4 insert—

PART O OVERHEATING
Overheating mitigation
O1
(1) Reasonable provision must be made in respect of a dwelling, institution or any other building containing one or more rooms for residential purposes, other than a room in a hotel (“residences”) to—
(a) limit unwanted solar gains in summer;
(b) provide an adequate means to remove heat from the indoor environment.
(2) In meeting the obligations in paragraph (1)—
(a) account must be taken of the safety of any occupant, and their reasonable enjoyment of the residence; and
(b) mechanical cooling may only be used where insufficient heat is capable of being removed from the indoor environment without it.

PART O OVERHEATING
Overheating mitigation
O1
(1) Reasonable provision must be made in respect of a dwelling, institution or any other building containing one or more rooms for residential purposes, other than a room in a hotel (“residences”) to— (a) limit unwanted solar gains in summer; (b) provide an adequate means to remove heat from the indoor environment. (2) In meeting the obligations in paragraph (1)— (a) account must be taken of the safety of any occupant, and their reasonable enjoyment of the residence; and (b) mechanical cooling may only be used where insufficient heat is capable of being removed from the indoor environment without it.