The staging process

The designers

While the DETR is mindful of the industry’s ability to deliver, the design professions are equally concerned that quantum leaps in energy efficiency are needed if the UK is to hit its carbon targets. The design group was therefore keen that the DETR sticks to its plans and does not allow future stages to slip.

In principle the airtightness values were thought appropriate. However, the designers were concerned that the BRE and BSRIA database does not include a wide enough spread of building types – particularly high-rise buildings – to implement the standard for all non-domestic buildings.

The staging of U-value improvements was supported, although it was felt that the values for non-domestic buildings were governed by the housebuilding sector. “Office buildings need not be dictated by the same factors,” reported session facilitator Chris Twinn, “so perhaps we can push for quicker improvements.”

The designers were also concerned that existing buildings presented a bigger threat than new build, and that by stage 4 the triggers that define ‘material alteration’ – such as change of tenancy – need to be more clearly and frequently defined for certain elements. “Existing buildings are the biggest problem,” said CIBSE President David Wood. “I would like to see a programme to improve the energy performance of a house every time it changes hands.”

As ECON 19 includes buildings of 1989 vintage in its database, the designers felt that the ECON 19 pass mark in stage 1 of Part L could either be raised from the median, or the ECON 19 database be updated by 2001. Existing buildings could be expected to perform no worse than typical. Best practice levels should be expected of new buildings by 2008, subject to consistencies with other assessment methods.

Logbooks and metering were regarded as important mechanisms for ensuring buildings deliver their energy targets, but until reporting is required they are not likely to be used. “Energy reporting should be brought forward to stage 2,” said Chris Twinn.

Slough Estates’ Peter Thompson wanted more guidance on where to put the energy meters, and for the logbooks to relate to the design of the building as much as to the installation.

Specific fan power values were welcomed, with the proviso that the values tighten to 1.5 W/litres/s for new buildings, and 2·0 W/litres/s for existing buildings at stage 4. “It will need to be categorised by building type,” said Twinn, “otherwise how will buildings with hepa filters meet the Regulations?”

The clients

The client and developer group was adamant that the 75% interim allowance should not go in the Regulations. By the same token the Regul-ations need to be underpinned by good technical details, and those details have yet to be published. The group agreed with the airtightness value for 2008, provided that the health and ventilation effectiveness issues are covered.

Again, the median value in ECON 19 was considered too lax for the Carbon Performance Index. But rather than rack up the value to the “best practice” level, it would be better to improve the ECON 19 database, said the clients.

Overall the clients demanded greater clarity from the Regulations, stating that they were simply too complicated in their presentation for people to understand all the issues. And if they can’t understand them now, how can they be expected to implement them?

“As they stand, the Regulations are not clear on how to deal with variations in building types,” said Peter Thompson. “Even among the experts there seems to be a lack of agreement as to what constitutes compliance. There is already a major problem in the interpretation of existing regulations across the regulating authorities, and to introduce more uncertainty is not something I would want to see.”

The manufacturers

Again, there was unanimity on the airtightness proposals. “The choice of windows and doors will become more important,” predicted Jack MacFarland, “but they won’t add much to the cost of the building.”

The U-values were also generally supported, although the manufacturers considered that the wall U-value of 0.25 W/m²K could be brought forward to 2002. The poorest permissible U-value was also thought too high, and the group suggested this be improved to 0.45 W/m²K for 2001, and 0.3 W/m²K for 2008.

Manufacturers also thought that the median value for ECON 19 was too lax, and that this could be raised to the upper quartile (‘good practice’) by 2005 or even 2003. Heat recovery should be covered in the Regulations, and Terry Seaward of Calorex suggested that heat pumps should be in the heating system efficiency section.

Conclusions

There was a general view that the proposals were good, that the technology exists to make them workable, and that there was good agreement across all sectors.

“It is important for industry to understand the political and parliamentary context,” explained Summit chairman, Graham Watts. “Some things can only be altered with a great deal of support and changes to primary legislation.”

There is clearly a big opportunity for the expansion of approved inspectors and the development of a competent persons register. The institutions seem keen and Graham Watts agreed that it was the role of the Construction Industry Council to reach consensus across the industry.

The main concerns of the Summit delegates were the lack of clarity in the technical guidance, the timing of some of the measures, and the absence of guidance for buildings other than offices and dwellings. “It is also clear that the industry has major concerns over the ability of building control to cope with these proposals,” said Watts.

BSRIA’s Chris Marsh echoed the concerns of the institutions at the Summit when he raised problems with the implementation of the regulations, despite the ready availability of technology and knowledge.

“The timing in the Regulations is achievable,” said Marsh, “but industry will have to invest in products and processes and testing equipment. No-one will do that,” he added, “until the timing is certain, and it won’t be certain until the training is in place and the competency is right.”

Building Services Journal would like to thank all delegates who took part in the Part L Summit, and extends particular thanks to the DETR, Graham Watts of the Construction Industry Council and the session facilitators. The Summit was also made possible by the kind sponsorship of Vent Axia.