Section 2: The requirements

2.1 This Approved Document, which takes effect on 1 October 2010, deals with the energy efficiency requirements in the Building Regulations. Regulation 2(1) of the Building Regulations defines the energy efficiency requirements as the requirements of regulations 23, 25A, 25B, 26, 28, 29 and 40 and Part L of Schedule 1. The energy efficiency requirements relevant to this Approved Document, which deals with existing dwellings, are those in regulations 23, 28, 29 and 40 of, and Part L of Schedule 1 to, those Regulations and are set out below.

The requirements

Requirements for the renovation or replacement of thermal elements – Regulation 23

Where the renovation of an individual thermal element—

(a) constitutes a major renovation; or

(b) amounts to the renovation of more than 50% of the element’s surface area;
the renovation must be carried out so as to ensure that the whole of the element complies with paragraph L1(a)(i) of Schedule 1, in so far as that is technically, functionally and economically feasible.

Where the whole or any part of an individual element is proposed to be replaced and the replacement—

(a) constitutes a major renovation; or

(b) (in the case of part replacement) amounts to the replacement of more than 50% of the thermal element’s surface area;

the whole of the thermal element must be replaced so as to ensure that it complies with paragraph L1(a)(i) of Schedule 1, in so far as that is technically, functionally and economically feasible.

Consequential improvements to energy performance Regulation 28

Paragraph (2) applies to an existing building with a total useful floor area over 1000 m² where the proposed building work consists of or includes—

an extension;

the initial provision of any fixed building services; or

an increase to the installed capacity of any fixed building services.

Subject to paragraph (3), where this paragraph applies, such work, if any, shall be carried out as is necessary to ensure that the building complies with the requirements of Part L of Schedule 1.
Nothing in paragraph (2) requires work to be carried out if it is not technically, functionally or economically feasible.

Requirement

Schedule 1 – Part L Conservation of fuel and power

L1. Reasonable provision shall be made for the conservation of fuel and power in buildings by:

(a) limiting heat gains and losses—

(i) through thermal elements and other parts of the building fabric; and

(ii) from pipes, ducts and vessels used for space heating, space cooling and hot water services;

(b) providing fixed building services which—

(i) are energy efficient;

(ii) have effective controls; and

(iii) are commissioned by testing and adjusting as necessary to ensure they use no more fuel and power than is reasonable in the circumstances; and

Regulation 40 providing to the owner sufficient information about the building, the fixed building services and their maintenance requirements so that the building can be operated in such a manner as to use no more fuel and power than is reasonable in the circumstances.

LIMITATION ON REQUIREMENTS

2.2 In accordance with regulation 8 of the Building Regulations, the requirements in Parts A to D and F to K (except for paragraphs G2, H2 and J7) of Schedule 1 to the Building Regulations do not require anything to be done except for the purpose of securing reasonable standards of health and safety for persons in or about buildings (and any others who may be affected by buildings or matters connected with buildings).

2.3 Paragraph G2 is excluded as it deals with water efficiency and paragraphs H2 and J7 are excluded from regulation 8 because they deal directly with prevention of the contamination of water. Parts E and M (which deal, respectively, with resistance to the passage of sound, and access to and use of buildings) are excluded from regulation 8 because they address the welfare and convenience of building users. Part L is excluded from regulation 8 because it addresses the conservation of fuel and power.

2.4 In addition, regulation 4(2) of the Building Regulations states that where the work is being carried out in order to comply with regulation 23 (requirements relating to renovation or replacement of a thermal element), regulation 22 (requirements relating to a change of a building's energy status) or regulation 28 (consequential improvements to energy performance), and is not a material alteration, it need comply only with the requirements of Part L.