Two houses built to code level four and six out of traditional material prove to be much more expensive than previous estimates
The cost of building zero-carbon homes using traditional materials could be higher than initial estimates according to a study by Tarmac Building Products.
The findings come following an initiative by the company together with affordable homes developer Lovell and the University of Nottingham's Department of the Built Environment, which involved the construction of two homes using brick and block material - one to Code for Sustainable Homes level four and one to level six.
Both properties are traditional semi-detached homes which tested the commercial viability of building low and zero carbon homes. According to the findings the level four home could be built for £6,401.45 on top of the costs of a typical home of this size, less than the £9,000 previously estimated. However, the zero carbon, level six home cost an additional £37,762.95 per unit, significantly higher than the £31,000 suggested by the industry. This used a super-insulating envelope with a biomass boiler, solar hot water system and photovoltaics.
Darren Waters, Tarmac Building Products, executive director - commercial, said the aim of the project was to try and develop a commercial house type which can be built using traditional products and techniques. “The results of the project also provide the industry with an accurate financial indication of building low and zero-carbon homes. While, it is good news for housebuilders in the medium-term that the costs for code level four are lower than previously expected, the higher costs of the code level six suggest that previous industry forecasts should be revised upwards”.