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Part L 2010 – where to start: an introduction for house builders and designers (NF28)


The overall aim of the 2010 revisions to Part L – to achieve a 25% improvement in CO2 emissions – is an important step towards the zero carbon target for new homes.

As a starting point for design and specification, this new guide, which was supported by DCLG, the Modern Masonry Alliance and the UK Timber Frame Association, looks at the implications of the changes to the building regulations and explains ways for new homes to meet the revised Part L.

Summary of content

This guide is intended to help house builders and designers understand what the October 2010 changes to Approved Document L1A (Conservation of fuel and power in new dwellings) mean.

The new ADL1A builds on the process for demonstrating compliance established by previous versions. Together with the reduction in annual carbon dioxide (CO2) emissions there are also technical changes including an allowance for party wall heat loss.

The guide gives examples of some typical homes, outlining a combination of measures needed to comply with ADL1A 2010. The intention is to give a broad understanding of the specification that may need to be incorporated, as a starting point for detailed design. These are only representative approaches to compliance and the intention of ADL1A 2010 is very much to allow builders flexibility in how they might choose to comply with the new requirements.

The examples used are based on typical homes on typical developments, from information gathered by NHBC about the homes being built today. These examples were used by the Zero Carbon Hub (ZCH) for their work on the Fabric Energy Efficiency Standard (FEES) and the definition of zero carbon homes that will apply from 2016.

This is only a general guide and there is no obligation to adopt any of the typical approaches given. You should always check with the Building Control Body that your proposals comply with the requirements of the Building Regulations. As part of your Building Regulations application you will have to provide a CO2 emissions rate calculation for your new home using the Government’s Standard Assessment Procedure (SAP 2009) before construction work commences and again on completion. You will also need to comply with NHBC Standards and planning requirements, etc.