Now that an evidence-based report has been published, both our industry and government have a structured review of how and where the performance gap occurs within the current house building process.

The report, "Closing the Gap between Design and As-built Performance", researched and developed by the Zero Carbon Hub, has to date been used to prioritise the issues that are considered to be the major contributors. The prioritisation process has been based upon the extent of evidence found, and the implications this evidence has on the performance gap.

This report may be new but the issues are not.

For the last decade innovators in the structural timber sector have been developing solutions to address areas of thermal bridging that occur when there is a gap between materials and the structural surfaces. By improving the airtightness of the building fabric and the thermal performance of the structure – cold bridging can be eliminated and thermal performance enhanced – reducing heat loss, carbon emissions and ultimately, offering vast savings on energy consumption to the home owner.

Widely known as the Fabric First approach, engineered timber, timber frame and SIP manufacture are all technologies looking to maximise offsite manufacture and have embraced these building principles. They are now gaining traction with the end users – home owners and developers – particularly in the self-build and social housing sectors, where sustainability and ‘whole life costs’ of the building are crucial to the specifying decision process.

Within the traditional masonry housing construction sector, the Fabric First principles equally apply but have not gained as much momentum. In the main this is because it is more difficult to control the process and workmanship with the onsite build, which are often subject to skills level deficiencies, out of sequence working and adverse weather conditions.

Quality control can be managed within factory conditions – hence the resurgence of the offsite industry. The structural timber sector, even during the recession, has invested in research to bring new innovative products to market and these products are now commonly performance tested. The terms, ‘cost certainty’ and ‘assured performance’, are now a fundamental part of our dialogue.
Factory fitted doors and windows with membranes to seal the gap to the structure further enhance performance and when combined with highly insulated, structural timber systems, eliminate the need for bolt-on technologies such as solar panels.

Architects, designers and specifiers now have a better understanding of the advantages of structural timber systems. Aside from wood being the most sustainable construction material, the benefits of speed, strength and assured performance, even up to Passiv Standards, if the brief demands, are now widely documented and understood.

The research within this Zero Carbon Hub report presents a great opportunity for those operating in the timber sector to further advance products and performance. More stringent building regulations play to the strengths of the industry, and with organisations such as the Structural Timber Association, planning activity programmes to share the learnings and advise members and clients on how to further address this national issue – the report is essential reading for all operating in the timber sector.

All aspects of the Zero Carbon Hub report will be addressed at the forthcoming Fabric First Event in Birmingham on 24 June, with Timber Expo sponsoring, and these issues will be further discussed in the Structural Timber Association seminar theatre at Timber Expo on October 7-8 at the NEC.

For those interested to find out more visit, or to join the Structural Timber Association visit