1.1 This approved document, which takes effect on 6 April 2014, deals with the energy efficiency requirements in the Building Regulations 2010. Regulation 2(1) of the Building Regulations defines the energy efficiency requirements as the requirements of regulations 23, 25A, 25B, 26, 26A, 28, 29 and 40 and Part L of Schedule 1. The energy efficiency requirements relevant to this approved document, which deals with new dwellings, are those in regulations 25A, 26, 26A, 29 and 40 and Part L of Schedule 1, and are set out below. NOTE: Regulation 25B 'Nearly zero-energy requirements for new buildings'; will not come into force until 2019 at the earliest. Statutory guidance on how to comply with regulation 25B is not included within this approved document and will be provided nearer to the time that regulation 25B comes into force. 1.2 Relevant extracts from the Building Regulations 2010 or the Building (Approved Inspectors etc.) Regulations 2010 (both as amended) are set out using text against a green background in this approved document. Where there is any doubt you should consult the full text of the regulations, available at www.legislation.gov.uk 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.
1.3 In the Secretary of State's view, compliance with the energy efficiency requirements could be demonstrated by meeting the five separate criteria set out in the following paragraphs. Compliance software should produce an output report to assist BCBs check that compliance has been achieved. NOTE: The output report can benefit both developers and BCBs during the design and construction stages as well as at completion. 1.4 Criterion 1: in accordance with regulation 26, the calculated rate of CO2 emissions from the dwelling (the Dwelling CO2 Emission Rate, DER) must not be greater than the Target CO2 Emission Rate (TER). Additionally, and in accordance with regulation 26A, the calculated Dwelling Fabric Energy Efficiency (DFEE) rate must not be greater than the Target Fabric Energy Efficiency (TFEE) rate. The TER/DER and TFEE/DFEE rate calculations are determined using the procedures set out in paragraphs 2.8 to 2.30. NOTE: Criterion 1 is a regulation and is therefore mandatory, whereas the limits for design flexibility for Criteria 2 are statutory guidance. The calculations required as part of the procedure to show compliance with this criterion can also provide information for the energy performance certificate required by regulation 29 of the Building Regulations and by the Energy Performance of Buildings (England and Wales) Regulations 2012 (SI 2012/3118). 1.5 Criterion 2: the performance of the individual fabric elements and the fixed building services of the building should achieve reasonable overall standards of energy efficiency, following the procedure set out in paragraphs 2.31 to 2.37. NOTE: Criterion 2 is intended to limit design flexibility, to discourage excessive and inappropriate trade-offs. For example, individual building fabric elements with poor insulation standards being offset by renewable energy systems with uncertain service lives. 1.6 Criterion 3: the dwelling should have appropriate passive control measures to limit the effect of heat gains on indoor temperatures in summer, irrespective of whether the dwelling has mechanical cooling. The guidance given in paragraphs 2.38 to 2.42 of this approved document provides a way of demonstrating reasonable provision. NOTE: The purpose is to limit solar gains and heat gains from circulation pipes to reasonable levels during the summer period, in order to reduce the need for, or the installed capacity of, air-conditioning systems. Criterion 3 should be satisfied even if the dwelling is air-conditioned. 1.7 Criterion 4: the performance of the dwelling, as built, should be consistent with the DER and DFEE rate. Use the guidance in Section 3 to demonstrate that this criterion has been met. 1.8 Criterion 5: the necessary provisions for enabling energy-efficient operation of the dwelling should be put in place. One way to achieve this is to follow the guidance in Section 4.