Acknowledgments
Extracts from the following documents are reproduced with permission:
DTLR. The Building Regulations 2000. Conservation of fuel and power. Approved Document L2 – Conservation of fuel and power in buildings other than dwellings. 2002 Edition. The Stationery Office. Crown copyright 2001. Free download available at
http://www.safety.dtlr.gov.uk/bregs/brads.htm BRE Digest 457. The Carbon Performance Rating for Offices. P F Grigg. Published by CRC Ltd, 151 Rosebery Avenue, London, EC1R 4GB. Tel: 020 7505 6622. Fax: 020 7505 6606. Email: enquiries@bre.co.uk
Introduction
Methods for demonstrating compliance with The Building Regulations Part L2 (2002 Edition) are set out in Approved Document L2[2] (‘ADL2’) and related publications.
This manual describes how the methods described in Approved Document L2 are implemented within the <Virtual Environment>.
An outline of the Part L regulations is provided in the Part L User Guide. Approved Document ADL2 should be consulted for a detailed account of the L2 provisions.
Guidance on the Part L regulations is provided on BRE and ODPM websites[10,11,12,13]. Guidance on the Part L2 Carbon Emissions Calculation Method is provided in the CIBSE/ODPM publication TM32[14].
Not all the requirements of Part L can be tested in software. The scope of the <Virtual Environment> implementation is described in the Part L User Guide.
The broad requirements of L2 are set out in ADL2 Section 0: General guidance. They cover:
L2 (a) Limiting fabric heat loss, summertime heat gains and heat losses by air infiltration
L2 (b) Limiting heat loss from pipes and ducts
L2 (c) Efficiency of heating systems
L2 (d) Limiting solar heat gains and their effects
L2 (e) Efficiency of mechanical ventilation and air-conditioning systems
L2 (f) Limiting heat gains to pipes and ducts used in air-conditioning.
L2 (g) Efficiency of lighting systems
L2 (h) Providing information on the operation and maintenance of building services systems.
Section 1 of the Approved Document sets out three methods that can be used for demonstrating that reasonable provision has been made for the conservation of fuel and power. These are:
“a) an Elemental Method (paragraphs 1.7 – 1.68). This method considers the performance of each aspect of the building individually. To comply with the provisions of Part L, a minimum level of performance should be achieved in each of the elements. Some flexibility is provided for trading off between different elements of the construction, and between insulation standards and heating system performance.”
“b) a Whole-Building method (paragraphs 1.69 – 1.73). This method considers the performance of the whole building. For office buildings, the heating, ventilation, air conditioning and lighting systems should be capable of being operated such that they will emit no more carbon per square metre per annum than a benchmark based on the ECON 19 data[4]. Alternative methods are also provided for schools and hospitals.”
“c) a Carbon Emissions Calculation Method (paragraphs 1.4 – 1.76). This method also considers the performance of the whole building, but can be applied to any building type. To comply with the provisions of Part L, the annual carbon emissions from the building should be no greater than that from a notional building that meets the compliance criteria of the Elemental Method. The carbon emissions from the proposed building and the notional building need to be estimated using an appropriate calculation tool.”
Within each method a number of requirements are laid down. In some cases compliance with a requirement may be demonstrated by more than one method. Each method specifies certain requirements, which in turn may be complied with by various methods, and so on.
