Policy Initiatives - Eco Homes

Within the EcoHomes rating scheme, points are allocated for a range of specific attributes within the design of the building. While these cover a broad range of areas from energy efficiency to assessment of flooding risk and provision of cycle storage, the areas directly influenced by the choice of heating system include Energy Rating, NOx Emissions and Renewable and Low Energy Sources.

Energy Rating

A significant proportion of the points allocation is derived from the energy efficiency of the building, in particular its DER (Dwelling Emissions Rating). The aim of this is to minimize carbon dioxide emissions to the atmosphere arising from the operation home and its services.

Credits are awarded on the basis of SAP2005 calculated CO2 emissions, based on kgCO2/m2/yr. It is necessary for a SAP accredited assessor to carry out the SAP rating.

Measures to reduce DER carbon dioxide emission levels are covered in detail under the SAP section of this website. These include:

  • Building fabric improvements
  • Reduction in glazed areas
  • Heated common areas
  • Reduced air permeability
  • Reduced hot water storage capacity
  • Improved heating system controllability
  • Inclusion of supplementary renewables
    (eg solar thermal or heat pumps)
  • Use of high efficiency mechanical ventilation with heat recovery

Under the energy rating, credits are also awarded for improved building fabric standards – future proofing the efficiency of the building over its whole life, for the provision of eco-labelled appliances and for the installation of energy efficient internal and external lighting.

NOx Emissions

Credits are awarded on the basis of NOx emissions arising from the operation of all space heating and hot water systems across the development.

While this is predominantly aimed at fossil fuelled boiler applications, due to the high NOx content of grid source electricity, electric heating systems connected to the grid are unlikely to meet the requirements.

The use of renewable or on site generated electricity is however acceptable. Special consideration is also provided for the use of Heat Pumps and the level of credit awarded will be dependent of the seasonal efficiency (i.e. the percentage of total electrical power required) of the heat pump.

Renewable and Low Energy Sources

Credit is also provided by the use of either renewable or locally generated energy to supply a significant proportion of the developments energy demand.

Maximum credits are awarded where 15% or more of the total energy requirement of the development is met by renewable or low energy sources. Heat Pumps are included within the scope of this, including ground, air or water source variants. Typically applying heat pumps to 30-40% of the dwellings on a development will yield the 15% requirement to achieve full credits under this area.