Building Regulations & Future Building Standards

As presented in the preceding pages, the Government has signalled its intention to significantly reduce energy use in buildings as an importnant element in its climate change strategy, and its approach to securing energy supplies in the future. The minimum energy efficiency requirements in Part L (& section6 Scotland) of the Building Regulations are one of the mechanisms through which these reductions are to be achieved. The latest revision of Part L came into effect in October 2010.

Figure 1 sets out, with respect to carbon emissions, the improvements over the 2006 standards that are targeted for the 2010 regulations, 2013 and 2016. These equate to the energy performance standards in the Code for Sustainable Homes Levels 4 and 6 respectively.

In line with the requirements of Article 3 on the Energy Performance of Buildings Directove (EPBD), the 2006 revision of Part L moved the basis of compliance from standards given for each construction element and building service to an overall CO₂ emissions target, the Target Emissions Rate (TER) for the whole building.

This target is based on a notional dwelling defined in terms of the elemental standards (U-values, area allowances, boiler efficiencies etc) that prevailed in the 2002 edition of Approved Document L1. The 2002 Approved Document was chosen as the datum because it gave a set of standards that the construction industry was familiar with in terms of construction specifications and real constructional products and materials.

This enabled them to extrapolate the physical implications of the proposed higher standards.

Target CO₂ emissions for new dwellings are calculated using SAP 2009 using the following formula:

TER = (CH x fuel factor + CL) x (1 - improvement factor)

Where:

CH is the emissions calculated using SAP 2005 that would arise from the provision of heating and hot water (including fans and pumps) complying with the 2002 Approved Document standards.

CL is the emissions arising from internal fixed lighting as determined to comply with the 2002 Approved Document standards.

Fuel factor is a factor depending on the primary heating fuel.

Improvement factor is the target improvement from the 2002 base line for a gas-heated dwelling.

Until 2013 the standard continues to be set with reference to those sources of emission (space, water heating and lighting) that were contained in the 2006 regulations and to offer the option of adopting Low and Zero Carbon (LZC) technologies.

To step to zero carbon in 2016 is likely to include emissions from other sources (principally electrical appliances), which would result in the need for significant renewable generation capacity as well as other LZC systems.