New Building Regulation Requirements
These new regulations use SAP2005 as the only method to demonstrate compliance.
To implement the legislation of the EPBD there is now a requirement to use a whole house compliance method. All new dwellings at the planning stage will have to demonstrate that an acceptable carbon dioxide emission rate will be achieved. A Target Carbon Dioxide Emission Rate (TER) has to be calculated within the Standard Assessment Procedure (SAP).
This will be based on a notional dwelling built to the 2002 standards with a target reduction of 20%. The actual Dwelling Carbon Dioxide Emission Rate (DER) must then be no worse than the TER. The new SAP 2005 incorporates all these calculations.
On completion of the dwelling an Energy Performance Certificate must be produced based on the actual construction, incorporating any changes to the performance of the fabric or services between design and construction.
In essence this will mean lower U values, higher boiler efficiencies and the integration of renewable energy with a certain degree of flexibility for designers.
There are limits on heat loss through the fabric of the dwelling, on excessive solar gain and heat gains/losses from pipes, ducts and vessels used for space heating, cooling and hot water. There is a requirement to provide energy efficient and properly commissioned heating and hot water services and provide the owner/user enough information so the dwelling and its services can be operated at their full potential.
The new Regulations make reference to the Domestic Heating Compliance Guide. This has been developed by Government with the Heating Industry and covers all aspects of domestic heating including gas, oil, solid fuel, hot water, solar thermal, under-floor heating, combined heat and power and heat pumps. As the title states this will indicate how to ensure your heating and hot water systems comply with the requirements of the Regulations. The minimum efficiency for gas boilers is 86% and oil is 85% (until 2007) as introduced in the April 2005 revision to Part L.
There is also now a requirement for post construction air pressure testing to be carried out on a sample of each dwelling type and remedial measures undertaken if they fail.
The nature of building work on existing dwellings requires a more elemental approach and accordingly controlled elements have U value targets set at 0.3 for walls; 0.16 for roofs (0.2 for slope) and 0.22 for floors.
Replacement windows and doors are controlled fittings and windows should have a minimum U value of 1.8 and glazed doors 2.2
Controlled services remain similar to the existing regulations with further details provided in the Domestic Heating Compliance Guide. New and replacement gas boilers must have minimum efficiency of 86% (SEDBUK B and B) with limited exceptions, assessed as described in the Guide to Condensing Boiler Installation Assessment for Dwellings. Oil boilers must have a minimum efficiency of 85% (until 2007).
There are also now minimum efficiencies for solid fuel boilers and individual heating appliances and a requirement for:
There is also a requirement for the provision of low energy lighting internally and externally Controlled services, elements and fittings are subject to Building Control inspection and a Building Notice will normally have to be provided. An alternative to this is for the work to be self certified by a suitably qualified competent person who has registered with a self certification body, such as CORGI for gas boilers, OFTEC for oil boilers and FENSA for windows.