Building regulations are a key policy measure to improve the energy efficiency of UK’s built environment. Energy use in buildings accounts for half of the country’s CO2 emissions.
Last summer the Government consulted on proposals to substantially tighten the regulations, improving energy efficiency by some 25% and saving at least 1 million tonnes of carbon per year by 2010 (ENDS Report 355, pp 54-55 ).
However, this aspiration could be severely undermined by poor enforcement. Last year, a small-scale study by the Building Research Establishment (BRE) for the Office of the Deputy Prime Minister warned that as few as 30% of newly built homes complied with the regulations on air tightness.
As a follow-up, BRE and National Energy Services carried out a further programme of air permeability tests on a larger sample of homes, and also made general observations of factors influencing energy efficiency. The work was commissioned by the Energy Saving Trust, on behalf of the Energy Efficiency Partnership For Homes.
The new study found that almost a third of new properties failed to achieve the air permeability level required by the regulations. It looked at 99 new homes throughout England - 60 houses, 36 flats and 3 bungalows. Flats - which were under-represented in the first survey - performed relatively well with 87% reaching the standard, compared to just 57% of houses.
One cause for the non-compliance was a lack of sealing around boiler flues and service pipes penetrating the walls of kitchens and bathrooms, the report says.
Surprisingly, more corners had been cut in luxury homes. The walls of these buildings tend to be penetrated by more pipes from extra bathrooms and appliances.
Gaps or poor sealing were also noticed around loft hatches, window frames and external doors - some of which were simply a poor fit in the frame. Many trickle ventilators appeared to leak as much air when closed as they did when open and some leakage was observed from the junctions between walls and floors.
Builders are given considerable freedom to trade off the efficiencies of different components of the building. This made it hard for the researchers to make judgements about the choices of materials or equipment used.
Builders of 22 of the homes said that they planned to install A-rated boilers when they applied for planning permission - but in reality they installed D-rated models. "It is not known whether the higher efficiency boilers were originally intended to balance another less efficient aspect of design," the report notes.
Overall, the differences between predicted and actual efficiency levels caused a 4.6% increase in CO2 emissions across the 99 homes, the authors calculate.
Junior ODPM Minister Phil Hope told Parliament in late December that the report was "cause for concern". He said that measures being considered in the current review of the building regulations include better guidance, dissemination and training, and expansion of the approved competent persons scheme.
Andrew Warren of the Association for the Conservation of Energy said that it is up to local authorities to enforce the law. However, building inspectors are warning that they will be hard pressed to cope with the increased workload when the new regulations come into force and are looking for Government funding to help them prepare (ENDS Report 358, p 57 ).
The Government has also proposed placing extra duties on builders to prove compliance. Last summer’s consultation suggested that they should be obliged to pressure test either two units of each building type or 5% of each building type, whichever is the greater.