The National Energy Foundation believes that there should be no change to the current insulation standard in homes receiving grant aid under ECO.
At the National Energy Foundation, we work on a daily basis to improve the use of energy in buildings. We firmly believe that there should be no change to the current insulation standard in homes receiving grant aid under the Energy Companies Obligation (ECO), which is set at 0.3w/m2K or better, for all types of walls, including solid walls.
With 27% of UK carbon emissions coming from our homes, we are going to have to make radical changes to meet our carbon reduction commitment of over 80% from all homes by 2050. Walls account for approximately 40% of the heat loss in a home so the addition of insulation is one area where we can make substantial savings.
Relaxing the current requirement will lead to missed opportunities, and homes that are not as well-insulated as they might be, for some of Britain’s most vulnerable residents. It will also result in lower savings being made on energy bills, and make it even harder for the Government to meet its target for cutting carbon emissions by 2050.
The main rationale for removing the current requirement for ECO-funded installations to achieve a U-value of 0.3w/m2K or less is that there may be an unacceptable loss of space. However, there are many different types of insulation materials available on the market today and many thicknesses which can achieve this target. We appreciate that the use of a wood fibre board internally would make the current target difficult to achieve without a substantial thickness of insulant. For example, the application of 100mm of Pavadentro to a 215mm masonry wall will only achieve a U-value of 0.35. However, other products require less space. For example, Kingspan Kooltherm K18 boards in a similar situation can achieve a 0.30 U-value with just 62.5mm of product and improved U-values are possible when the depth is increased; Spacetherm quotes achievable U-values of just 0.14.
Without the current 0.3 requirement there will be less interest from manufacturers to develop alternatives. This is innovation we desperately need. However, the National Energy Foundation is not unsympathetic to the challenges encountered on-site, and we are aware of the issues of delivery. Whilst we appreciate that setting an unachievable thermal conductivity target doesn’t promote energy efficiency, we don’t feel that the current target is actually unachievable, given the products already available. In fact, the current target can be exceeded, if the commitment is there but there is a requirement for appropriate education of specifiers. There will, of course, be cost implications and this is one of the reasons why efforts to meet the regulations are proving challenging. Where costs play a major issue in a build there will always be an obligation to keep them to a minimum. It is our belief that the very existence of requirements ensures compliance.
We also believe that a relaxation of the U-value requirement could open the system to abuse with those on-site encouraging either a cheaper product or less depth, in a bid to cut costs. The second rationale for the change is to avoid moisture issues. These should be considered at the planning stage and other mitigation strategies put in place. The number of cases where either the loss of space would be unreasonable or the moisture issues could not be managed would be minimal. We believe that we shouldn’t remove requirements across the board just to cater for a small number of exceptions.
Finally, something must be said about the monitoring of installations. It is clear, and has been for some time, that solid wall insulation installations often do not live up to expectations. There are a number of reasons for this, for example:
Where a U-value target is specified, we would like to see this requirement audited. Both air-tightness testing on-site prior to handover and in-situ U-value measurement could be introduced for a percentage of installations. Thermal cameras could also be used to highlight inefficient installations. The mantra ‘without monitoring we can’t manage’ needs to be followed if we are ever going to achieve the 80% carbon savings we need from the UK’s domestic housing stock. The Government’s call for responses (Reference: URN 13D/167) is available on the Government website.