Sustainable Homes

The Code for Sustainable Homes is the national standard for the sustainable design and construction of new homes. It aims to reduce carbon emissions and promote higher standards of sustainable design above the current minimum standards set out by the building regulations.

The code provides 9 measures of sustainable design:

  • energy/CO2
  • water
  • materials
  • surface water runoff (flooding and flood prevention)
  • waste
  • pollution
  • health and well-being
  • management
  • ecology


The code uses a 1 to 6 star system to rate the overall sustainability performance of a new home against these 9 categories.

Zenex and GasSaver contribution to sustainability

Zenex, the inventor of the passive flue gas heat recovery device (PFGHRD), GasSaver, is committed to improving boiler and water energy efficiency in domestic and commercial properties. 

GasSaver efficiency has successfully been used in a number of developments to count towards achieving The Code for Sustainable Homes Levels 3 and 4.

To maximise the contribution of GasSaver to a particular dwelling consideration should be given to adjusting building fabric properties such as wall U-values and air permeability. Generally speaking, reducing U-values and air permeability values provides a better percentage saving for a given dwelling.

In some contexts, it may not be possible to achieve Code Level 3 without additional energy saving measures.  In such cases, the use of other low cost methods to improve the DER can be explored, such as mechanical ventilation with heat recovery.

The Energy Saving Trust provides further insight

The Energy Saving Trust offers insight into the background and development of the Code for Sustainable Homes.

You can also find more information about the criteria and percentages associated with Code Levels.



The Code for Sustainable Homes logo

Sustainable Homes Construction and Development

Consider greener, more energy efficient boiler performance for sustainable buildings' construction and development