In England and Wales there is a fair amount of steam being generated by the new Building Regulations for energy conservation in new homes.

The Approved Document Part L1A provides the latest standards for new dwellings. In line with current government thinking on climate change and sustainability, it sets challenging targets for the energy efficiency of new homes.

The new regulations are also markedly different in their approach from the previous regulations in the way compliance can be demonstrated. Gone are the “elemental” and “target U-value” routes. Developers and designers now need to adopt a “whole house” approach, combining a broad range of factors, including insulation, air permeability, the efficiency of the heating systems and controls, and primary fuel type.

Reduced U-values for the building envelope components such as the floor, external walls and roof all help to deliver a significant proportion of the 20% improvement that the regulations require – but they cannot deliver compliance in isolation from other factors. What’s worse from the housebuilder’s point of view is that all dwelling types are now subject to a mandatory airtightness test, checking whether the home “as built” really lives up to the promise on paper.

So how does this affect developers using timber frame construction? The news is good.

Adopting a 140mm stud depth in standard open frame wall panels allows a designer to achieve lower U-values with little or no change to the wider technical specification. Using the 140mm solution achieves U-values between 0.30 and 0.27 using readily available and standard insulation – and the use of higher performance insulation and insulating breather membranes can boost these figures even further.

No-brainer

Even ground floor flats with electric heating could still pass the regulations if they are built using the 140mm timber frame solution – something that the housebuilding industry would find a great advantage. And, as a housebuilder told me recently, if you can do that with this sort of house type, then the rest is pretty much a no-brainer.

The 140mm stud option is already the norm for more than half of all timber frame homes built today. It’s standard for multi-storey construction, and social housing developers have already largely embraced this solution as an easy way to achieve their energy and environmental targets. We anticipate the use of 140mm timber frame to become the overall industry standard as a direct result of the new Part L regulations.

Best of all, such a solution is comprehensively tried and tested. There are no nasty surprises waiting for housebuilders, homeowners or the likes of NHBC and Zurich arising from the use of riskier practices to meet the new standards. It’s also a highly cost-effective solution, as confirmed by the recent National Audit Office report into modern methods of construction.

Thermal qualities

The good thermal qualities of wood can help control thermal bridging. Similarly, getting the balance right with ventilation is something to watch – the new Part F gives important guidance. Recent tests commissioned by the UK Timber Frame Association (UKTFA) confirm that well-built timber frame homes can comfortably be relied on to achieve the latest airtightness standards, but are often capable of doing even better. Quality of workmanship is key. All timber frame design, manufacture and erecting companies should be quality assured to UKTFA Q-Mark standards.

So the new Building Regulations need not get you hot under the collar. Overall, the message for housebuilders is a simple one: if you want to comply without costing the earth, make the change to timber frame.