Cost of building zero carbon homes is falling
Sweett Group research reveals sustainable premium has dropped below £5000 for semi-detached house
Report from – Jo Smit
The extra cost of building a new home to zero carbon standards has been driven down by cheaper photovoltaics (PV), policy change and greater efficiency in meeting airtightness standards. A study by Sweett Group for the Zero Carbon Hub has found that the typical additional cost of building a semi-detached house to the zero carbon standard can be less than £5,000 today, and could fall to under £3,500 within the next six years.
Today’s cost premium is significantly lower than the £12,000 figure calculated in 2011, according to 2010 Building Regulations. The drop in costs is partly due to the introduction of the allowable solutions mechanism, which permits developers to take offsite action to offset carbon emissions that cannot be cost-effectively mitigated on site.
However, reductions in the cost of key technologies, notably PV as well as air source heat pumps and high-performance glazing, have also contributed. The report expects the overall premium to continue to come down, as PV prices reduce further, and the cost of achieving greater airtightness and tackling thermal bridging fall.
The report’s analysis is based on four representative housetypes, with the costs of achieving the zero carbon standard being based on the cumulative costs of meeting the fabric energy efficiency standard (FEES) or advanced practice energy efficiency requirements, together with a heating and/or low or zero carbon energy source sufficient to achieve carbon compliance and an allowance for allowable solutions to address the remaining regulated carbon emissions.
The additional cost allowances given for achieving the proposed zero carbon standard, compared to Part L1A 2013 of the Building Regulations are:
- £6,700-£7500 for detached homes now; £5700-£6300 by 2020
- £3700-£4700 for semi-detached and mid-terraced homes now; £2900-£3600 by 2020
- £2200-£2400 for low-rise apartments; £1900-£2000 by 2020.
Rob Pannell, managing director at Zero Carbon Hub, said: “What this report shows is that the zero carbon policy, while ambitious, is becoming more cost effective. The challenge is to continue innovating to keep costs as low as possible”.
Mike Landy, head of on-site renewables at the Renewable Energy Association, said: “This report adds to the growing body of evidence showing that the costs of solar PV are falling fast, and making it more affordable to build new ‘zero carbon’ homes. More importantly, this trend is expected to continue over the coming years, demonstrating the power of on-site renewables to bring down bills for homes and offices.
"We now look forward to the government moving quickly to set out the detailed roadmap for making all new homes zero carbon from 2016.”
To download the report, Cost analysis: Meeting the zero carbon standard, click here.