Part L compliance could add 5% to construction costs

Complying with Part L could add a hefty 5% to building construction costs according to new research from Gleeds and Hoare Lea.

The figure is more than double the 2% extra estimated by the ODPM, as revealed in the last issue of QS News.

Gleeds and engineering consultant Hoare Lea said the government's estimate was based on the cost of minimum compliance but in reality complying with the new Part L could add 5% to projects. This was thought to be because clients want buildings to conform to 2011 standards, the year pencilled in for an even tougher version of Part L to come into force.

Ashley Bateson, Hoare Lea associate, said it was a "grey area" at present because there were lots of different ways for a building to comply with the regulation, with varying costs.

For example, on a glass-fronted building with 12,000m sq gross internal floor area, complying with Part L could cost up to 3.8% more, depending on the approach taken.

If the 100% glazed front was fitted with motorised louvers, the cost would be 3.76% more than a building that complied with 2002 Part L. If motorised blinds were adopted it would cost 2.88% more instead, while a glazed front with fixed external louvers would add 2.39%.

Bateson added that the government's SBEM technology was over-simplistic and threatened to allow non-compliant buildings past the design stage. "You won't necessarily get an energy efficient building by using the government approved SBEM," he warned.