The DETR is consulting on proposals to radically upgrade the energy efficiency of every building in the UK. What will the effects be of the Building Regulations' new Part L?
The DETR is set to back its tough stance on green issues with regulations that could revolutionise energy conservation in construction.

The plan is to reform Part L of the Building Regulations to make the industry and its clients improve energy-efficiency. If the DETR proposals make it through the consultation process, the beefed-up Part L will come into force next year.

The proposals include measures to introduce energy efficiency standards for air-conditioning and lighting for the first time, stiffen insulation standards, introduce mandatory airtightness testing and – most controversially – extend the regulations to cover existing buildings.

The extension to Part L would involve increasing insulation levels, installing double glazing and making buildings airtight. Experts agree that this will cost owners hundreds of millions of pounds – and provide plenty of work for contractors and surveyors.

Although it is not yet known how the regulations would be applied to existing buildings, one theory is that an energy audit would be carried out during rent reviews or building sales. The audit would reveal how much and what type of work needs to be done, and the upgrade work would have to be carried out before the sale or review was completed. The DETR's Ted King, who is marshalling the Part L consultation, has studied a similar programme instigated by the Danish government in Copenhagen. He says: "It costs about £300 for the survey alone." Michael Woodman-Smith, who is working on the Greenwich Millennium Village for architect Hunt Thompson Associates (now known as HTA Architects), is concerned that the move to include existing housing could have dire aesthetic consequences. "We have to be careful that old and beautiful buildings aren't lumbered with inappropriate PVCu windows," he says.

Woodman-Smith is also worried that more regulations will mean less freedom for the architect. "Our experience of refurbishing housing estates tells us that with limited funds, the architect has to choose the energy-saving measures that are most cost-effective. Regulations like these take the choice out of our hands," he says.

We have to be careful that old and beautiful buildings aren’t lumbered with inappropriate PVCu windows

Michael Woodman-Smith, Hunt Thompson Associates

Housebuilders have welcomed the move to include existing buildings as it will show that the houses they produce are energy-efficient. However, the powerful mortgage lenders lobby will probably try to block the move.

A spokesman from a leading building society said people may be prepared to pay for the work in the good times, but would be unwilling to foot extra costs in a recession.

Housebuilders are less supportive of moves to increase levels of insulation. A source in the DETR's Part L consultation group says a U-value of 0.28 W/m2°C for walls has been mentioned. This is a significant increase on the current target of 0.45 W/m2°C and could mean increasing insulation layers by 200 mm – double the best current insulation levels. Wimpey's chief architect, Martin Stamp, argues that the money would be better spent on upgrading the efficiency of domestic appliances.

Plans to stop builders sidestepping new insulation requirements are also causing concern. When regulators introduced the 0.45 W/m2°C standard in the 1995 Part L revision, builders achieved the target by installing low-energy condensing boilers and low-emissivity glass instead of tackling insulation. New proposals will aim to limit these trade-offs, says the DETR's King.

The DETR’s proposals to crack down on energy-wasting buildings

The procedures that may be brought into force by Part L Extension of Part L to existing buildings This move will raise the insulation standards of existing buildings. It is proposed that existing buildings undergo an energy audit to assess what improvements are required. Improvements could be carried out under maintenance or repair contracts. New rules for commissioning building management systems DETR-backed studies have shown that these are often badly commissioned and never fine-tuned to the needs of users. For instance, lights and heating are left on when the building is empty. Energy efficiency standards for air-conditioning, mechanical ventilation and lighting Although many users already consider the energy efficiency of powered equipment in their feasibility studies, this would be formalised in the regulations. Substantial increase in insulation standards Walls are to have U-values of 0.28-0.30 W/m2°C, and lofts 0.2-0.25 W/m2°C. The proposed U-value for windows is 0.20 W/m2°C – about half the current value. Compulsory tests for airtightness of buildings Airtightness is currently tested by leading clients such as Asda, but such testing procedures will be new to most of the industry. Using whole-building CO2 performance to show compliance with energy requirements This will encourage developers to take a wider look at energy efficiency, perhaps even including embodied energy (how much energy is used in the production of building materials). A public register of buildings’ energy performance A method of putting the worst performers to shame, and praising those that set the best examples.