The cost and benefits of building new homes to Code for Sustainable Homes level 5

B&NES council currently require, where viable, that new housing developments in Bath are built to Code for Sustainable Homes level 5. Code for Sustainable Homes Level 5 imposes high energy, water, security, disabled access and environmental standards on new homes, increasing build costs but not increasing house prices. It benefits home occupiers by reducing their energy bills by up to 80% and reduces carbon emissions by more than 50%.

Transition Bath feels that the economic benefits outweigh the additional capital costs, something the current coalition government disagrees with. We feel that the government under pressure from housing developers has consistently overstated the costs of building to higher standards and has understated or more recently completely ignored the benefits of reduced energy costs to home owners. This remainder of this post explores both the additional capital costs of Code for Sustainable Homes level 5 and the economic benefits to home owners, and why we think the government is wrong to abolish the Code for Sustainable homes and more importantly to stop all local council’s imposing higher standards. It is clear without these higher standards large builders will continue to build low quality, poorly performing homes with high energy consumption.

Capital Costs:

If we look at 4 cost studies of the Code for Sustainable Homes, we see a wide variety of additional cost estimates for Code for Sustainable Homes level 5:

Date Report Authors Commissioned by Cost Estimate per home Comments
Aug-11 Cost of Building to the CfSH: Updated Cost Review Davis Langdon/Element Energy DCLG


Used out of date solar PV prices which were at least a factor of 2 out
Jul-13 Housing Standards Review: Impact Assessment Harris DCLG


Used a Ground Source Heat Pump, which a builder would never do, added perhaps £6,000 to costs over a gas boiler
Aug-13 An updated cost review for CfSH Transition Bath


Sep-13 Costs of Building to CfSH AECOM/Element Energy B&NES + 4 other Councils



The two DCLG (Department for Communities and Local Government) studies both resulted in cost estimates double what Transition Bath think is reasonable, largely because they either chose expensive solutions (e.g. Ground Source Heat Pumps) or used incorrect Solar PV prices. We feel the recent Sep 2013 AECOM/Element Energy study for B&NES council provides a more realistic estimate. The high costs DCLG used in their studies significantly skews any cost-benefit analysis against the Code for Sustainable Homes.

Benefits to home occupiers:

Transition Bath estimates that building to CfSH 5 versus minimum building regulations provides the following benefits:

Minimum Building Regs kWh CfH 5 kWh Saving kWh Minimum Building Regs £ CfSH 5 £ Saving £ % CO2 Saving tonnes % CO2 Monetised Benefit






























Solar PV FIT S+ Export Electricity



Total inc FITS






Comments on these benefits:

  • A CfSH 5 home has a predicted annual energy bill of £682, 38% lower than that of a home built to minimum building regulation standards (£1,098)
  • If you include income from the FITs and exported electricity installed on the CfSH 5 home, the annual energy ‘cost’ reduces to £224, an 80% saving compared with the minimum building standard
  • The monetised savings are £8,567 without the FITs and £17,222 with the FITs, which compares well with the addition capital cost estimates of £8,500 (AECOM/EE/Sep2013) and £10,400 (Transition Bath/Aug2013) i.e. excluding costs the benefits of CfSH are close to the capital costs, and if FITs are included the benefits are approximately double that of the additional capital costs


Posted in Energy, Planning, Uncategorized.