New Part L comes into force

New Part L1A of the Building Regulations comes into force October 2010
 
The Government's Building a Greener Future policy Statement of July 2007, set out it's target of new homes being net zero carbon by 2016. Recent changes to part L1A of the building regulations implement a 25% improvement in energy efficiency standards, to be followed by a further 44% improvement in 2013, relative to 2006 standards. The regulations also make provisions for non residential building, with a similar 25% reduction, this year, with further steps towards zero carbon by 2019 under consideration.
 
How 'zero carbon' is to be achieved is not stipulated in the regulations, however it is accepted, that without renewable energy sources, it is not possible to achieve government targets, all the more so as increasing insulation and airtightness, has been found to result in decreasing returns in building performance. Good news for the renewable energy industry.
 
In case you were wondering what 'zero carbon' home actually means in relation to new homes, Here is the current definition as defined in the code.
 
A ‘zero carbon' home is where net carbon emissions resulting from ALL energy used in the dwelling is zero. This includes the energy consumed in the operation of the space heating/cooling and hot-water systems, ventilation, all internal lighting, cooking and all electrical appliances. The calculation can take account of contributions from renewable/loss carbon installations on/in the dwelling, or provided by an energy services company (ESCO) on/offsite, provided it directly supplies the dwelling. Alternatively it is acceptable to include, in the estimate of carbon emissions, the contribution from ‘accredited external renewables’. For a true zero carbon home, it will also be necessary to ensure that the fabric of the building significantly exceeds the standards currently required by Part L of the Building Regulations 2000 (as amended). The ‘heat loss parameter’ (covering the walls, windows, air tightness and other elements of the building design) must be no more than 0.8W/m2K.
 
CSH uses the SAP (standard assessment procedure) computation which takes into account energy consumed through heating, lighting and hot water provision. Homes will have to reach zero carbon for these factors using the SAP computation. Heat and power for this element must he generated either in the home, or on the development, or through other local community arrangements, (including district heat and power) and must be renewable (i.e. non-fossil fuel) energy. A zero carbon home is also required to have zero carbon emissions from use of appliances in the homes (on average over a year). SAP does not contain any provision for energy consumption of appliances but will be updated to do so in due course. Until SAP is updated the ‘appliances’ element of the qualification will be that each home must provide an amount of renewable electricity equal to a specified amount of kWh per metre squared of floor space, in addition to that required to meet zero carbon in the SAP 2005 to approximate to the average appliance energy consumption. This additional power must be renewable power, produced either within the area of the building and its grounds, elsewhere in the development or beyond, as long as the developer has entered into arrangements to ensure that the renewable generation is additional to existing plans. The amount of such additional power can be reduced by any surplus from the arrangements to meet zero carbon on heating, hot water and lighting.
Reference ‘The Green Bible’ Extracted from the CSH Technical Guide 2008.