Conservation of fuel and power: Approved Document L, Volume 2 — Buildings other than dwellings

O N L I N E V E R S I O N R28 Consequential improvements on installing or extending the capacity of fixed building services NOTE: Increasing the size of central boiler plant to serve a new extension would not generally increase the installed capacity of a fixed building service per unit area, unless the heating provision in the existing building was also increased at the same time. In these circumstances, paragraph 12.6 would not apply, but paragraphs 12.3 to 12.5 would continue to apply as a result of the extension. 12.6 If it is proposed to install a fixed building service in an existing building with a total useful floor area of over 1000m2, either as a first installation or as an installation that increases the installed capacity of a fixed building service per unit area, then both of the following should be implemented as consequential improvements. a. Make energy efficiency improvements to the fixed building services to meet the requirements of Part L, where this is practical and technically, functionally and economically feasible. i. When installing or extending the capacity of fixed building services, the value of the principal works is used to determine the minimum value of the energy efficiency improvements made to fixed building services as consequential improvements. The value of these consequential improvements should not be less than 10% of the value of the principal works, excluding the value of any work to improve other energy efficiency aspects of the building served by the services in meeting paragraph 12.6b. ii. The measures listed in Appendix D, Table D1, relate to this requirement, and may be considered technically, functionally and economically feasible in normal circumstances. iii. As part of the initial notice or deposit of plans, a chartered quantity surveyor or other suitably qualified person should produce a signed report that establishes the value of the principal works and the value of the consequential improvements using prices current at the date when the building control body is informed of the proposals. b. Improve other energy efficiency aspects of those parts of the building served by the fixed building service to meet the requirements of Part L, where this is technically, functionally and economically feasible. i. All technically, functionally and economically feasible measures to improve the fabric of the building served by the service should be implemented. The extent of the improvements to the fabric should not be determined by the value of the principal works. ii. The measures in Appendix D, Table D2 relate to this requirement and may be considered technically, functionally and economically feasible in normal circumstances. 83 Building Regulations 2010 Approved Document L Volume 2, 2021 edition O N L I N E V E R S I O N