Part L 2010 and Reducing CO2 Emissions

Aiming to reduce CO2 emissions by a further 25%

In October 2010, The Government updated Part L of the Building Regulations for England and Wales in order to move closer to its 2016 target for reducing carbon emissions under the Zero Carbon policy for the conservation of fuel and power.  The latest version of the regulations requires an overall 25% cut in carbon emissions across the board for dwellings compared with the 2006 version and is a 40% improvement over a dwelling built to 2002 regulations.

For house builders, Part L 2010 roughly corresponds to the energy component of level 3 of the Code for Sustainable Homes.  Social housing providers must already build homes to level 3 to receive government grants and all new homes have to be assessed against the code.  Some local authorities, including in London, require social housing to be built to code level 4.

There is growing evidence that completed dwellings do not in practice achieve the intended energy performance. This is referred to by government as the ‘performance gap’. If true zero carbon is to be achieved by 2016 it is vital that this gap be closed.  Part L1A 2010 contains items that aim to contribute to reducing the disparity.

Firstly, the document is clearer than previous versions in distinguishing between ‘Regulation’ and ‘Guidance’ and is less ambiguous in many places.  This should help housing developers better understand what is required of them.

Secondly, designers are required to put forward a ‘Design Submission’ with carbon dioxide emission ratings and an ‘As Built Submission’, including a comparison of specifications, which should bring more standardisation and rigor and help building control understand the compliance strategy of the proposed development.

Thirdly, the notion of ‘confidence factors’ should start to reward those developers who adopt good quality control procedures both in design and on site.  More of these confidence factors are expected towards 2013 and beyond.  Work is just beginning on the 2013 revision to Part L.  The overall target is another 25% cut in carbon emissions over 2010 Part L (44% over 2006) but this time round there may be a move away from percentage improvements over previous versions of Part L to absolute figures. This will help bring Part L in line with the work the Zero Carbon Hub has done on defining zero carbon for housing.