Flawed codes

A loophole in the Code for Sustainable Homes allows developers to build homes that produce higher carbon emissions than allowed under current Building Regulations and still achieve Levels 3 or 4 under the Code – according to the Good Homes Alliance (GHA), a group of developers committed to building and promoting sustainable homes and communities in the UK.

It is harder to achieve Levels 3 and 4 of the Code with more carbon efficient gas heating than with cheaper electric heating. This is because the ‘fuel factor’ used in Building Regulations and the Code to calculate the Target Emissions Rate (TER), from which you are then required to make your percentage reductions to achieve the different Code levels, allows much higher carbon emissions if you use electric heating. Starting from a higher base makes reductions easier, particularly when using a high carbon fuel-like electricity. This means developers installing electric heating can build a less insulated shell than those using gas to reach Levels 3 or 4 of the Code.

In addition, it is harder for smaller homes with more efficient building forms to achieve the required percentage reduction scale of carbon emissions to attain Levels 3 and 4. This is driving developers to increase the inefficiency of the building envelope and goes against the expectation of high Code standards in social housing.
The GHA recommends the Code for Sustainable Homes should rate all fuels equally based on their carbon emissions for Levels 3 and above, look at absolute energy use and carbon emissions figures and include a post occupation monitoring requirement on a percentage of new homes to test performance levels.

The GHA proposes to introduce a new Code Level to its members, to be known as Level 3++. This means Level 3 with two additional requirements: firstly a fixed maximum carbon or energy target per sq m of floor space per year set according to building type to ensure absolute energy and carbon reductions in new dwellings, and secondly post occupation monitoring of new homes for at least two years to compare the design objectives with the actual performance of the properties.

Neil May, Chairman of the GHA, comments: “Ironically, the loophole in the Code for Sustainable Homes is encouraging developers to install cheaper electric heating which produces higher carbon emissions, or to compromise on the building form. The Department of Communities and Local Government needs to take action to prevent this from happening, bringing in a flat carbon emissions standard.

“The Code plays an important role in reducing the carbon emissions of our housing and we support the Government fully in this aim. However, unforeseen glitches are not uncommon in new initiatives and we are actively involved in identifying these and proposing solutions to help ensure that the Code is a useful and trusted mechanism for achieving carbon reduction in new housing. The GHA is also developing further social requirements to promote community sustainability and low carbon living in the broadest sense.”

Jonathan Kingerlee, Chairman of Kingerlee Homes, which sponsored this analysis, added: “We focused this study on Code Levels 3 and 4 because we believe that the majority of the benefit of reduced energy use and lower carbon emissions can be achieved at these levels. If all new homes reached only these levels then the housebuilding sector as a whole would make a considerable and proportionate contribution to reducing emissions. But as the Code currently stands, this is not the case. In fact, if the majority of house builders take advantage of the electric heating loophole, then total emissions will not fall but rise, and the possibility that parts of the electricity network will be unable to cope with this extra demand becomes very real.”