New Part L software under fire

The software used for assessing compliance with Part L2A of the Building Regulations on energy efficiency is still causing problems for some in the industry.

John Tebbit, industry affairs director at the Construction Products Association, said: “Our view at the moment is that there are still some major issues with the SBEM (simplified building energy model) software. Some inspectors are still saying they won’t use the new software to approve a building.

“There still isn’t a ‘dummies guide’ to the new software, and we’ve been asking for nearly a year now. The Department for Communities and Local Government (DCLG) just hasn’t put the money up for it. We’re still arguing that the money for training is not sufficient.”

Bill Hawker, technical chairman of the National Association of Rooflight Manufacturers, said: “I’ve not seen the latest version of the SBEM software that was issued three weeks ago, but I do have concerns over the previous versions.

“I’ve seen 20% to 30% swings in the results from one version of SBEM to the next.

“When you consider that the new regulations are looking for a 28% saving in CO2 emissions and we are getting swings of that magnitude just by using a different version of the SBEM software, you can’t have much confidence in the results.”

His view was echoed by Clifford Dyer, director of the Metal Cladding & Roofing Manufacturers Association, who said: “The latest version of SBEM is still not user-friendly and there are quite a number of issues that need resolving.

“We’ve worked as part of a team with the Building Research Establishment (BRE) and so had some idea of how the new version would work, but some of the changes that have been introduced just seem to have made it more confusing.”

However, Ken Francis, principal engineer at the Steel Construction Institute, was more positive. He said that the latest version was producing better results and that buildings that should pass were now passing. “I’m not as anti as I was three months ago. It gives slightly different results to other packages, but talking to the BRE, I now understand that they have done that deliberately by emphasising elements such as a good lighting control systems. That’s because BRE thinks that lighting is an area where energy-saving measures are more easily achievable.”

He added: “I don’t think some users really understand the SBEM system, but there is good training and an exam available from the Low Carbon Consultants Register, which is run by the Chartered Institute of Building Services Engineers.”

José Ortiz, associate director of the Sustainable Energy Centre at the BRE, which developed the SBEM software, said: “We have had a lot of feedback from the industry on the functionality and user-friendliness of the software and we are being very reactive to industry concerns.

“We and the DCLG are very keen that people know we are using this information to improve the package, although some areas have to take priority.”

[Contract Journal, 1 November 2006, p13]