Revised Building Regulations (Part L) that increase energy efficiency of buildings have been published by the Government. They will come into force from April 6th 2006
Four new Approved Documents for new Energy Performance
L1A – Conservation of fuel and power in new dwellings
The new Approved Document L1A set performance targets for the whole building rather than for construction or elements. Part L1A, the Target CO2 Emission Rating (TER) for a dwelling, must be shown to be higher than the proposed Dwelling CO2 Rate (DER). This is the only calculation method allowable from April 6th, the current Carbon Index Method, Target Method (ADL: 2002) and Elemental Approach are no longer permissible for new dwellings
The requirements for new Dwellings Part L1A:-
- 20% reduction in emissions compared with Part L1 (2002)
- Now a Single compliance method – Whole-house carbon dioxide emissions target
- More control of solar overheating via SAP (2005)
- More control of construction quality
- Accredited construction details
- Improved Robust Construction Details are being developed
- Improved treatment of thermal bridging via SAP (2005)
- Sample pressure testing
- Air tightness seen as proxy for construction quality
- Provision of information to building control Authority, to the owner or occupier including services operating instruction s and EPBD (Energy Performance of Building Directive) certificate
Demonstrating construction quality
Conservatories.
- If conservatory is built as part of a new dwelling the performance of the dwelling should be assessed as if the conservatory were not there
- The guidance in AD L1B should be followed in the respect of the construction of the conservatory itself
- If a substantially glazed space is integral with the dwelling (i.e. there is no thermal separation) the space should be included as part of the dwelling.
Key documents for Approved Document L1A:-
The Code for Sustainable Homes. This document, due for publication in April 2006, intends to explain what makes a building sustainable and to do away with BREEAM ratings and EcoHomes schemes, etc in one unified standard.
The EPBD requires that a building Energy Rating be displayed to public view.
The BRE have produced a National Calculation Method software package for buildings other than dwellings (ADL: 2A and ADL: 2B
SAP: 2005 is currently available from www.bre.co.uk/sap2005.
Using Robust Standard Details (RSD) will reduce the need for air pressure testing although a checklist detailing compliance must be included in submissions to the Building Control Body. New RSDs are forthcoming.
The Air Tightness Testing and Measurement Association's (ATTMA) “Measuring Air Permeability of Building Envelopes” gives guidance on air pressure testing.
A checklist at the back of Approved Document Part L1A provides a step-by-step guide to ensure that all eventualities are covered.
Please note these brief guidance notes are not a substitute for reading the regulations and the Approved Documents (ADs).
For a more authoritative guide you are advised to use the link below to go to the Regulation of Ads.
