Responsible Retrofit of Traditional Buildings Report

The Sustainable Traditional Building Alliance has voiced strong concerns in its report, Responsible Retrofit of Traditional Buildings, which examines existing research and guidance on the retrofit of pre-1919 buildings.

Traditional buildings perform differently to modern buildings. This means we have to be careful not to assume that models, guidance and products used in current build will deliver the same predicted benefits. In fact, they may underperform, or worse, have unintended consequences.

The report raises some important concerns:

1) lack of quality research

“There is a general absence of literature surrounding the energy behaviour and performance of traditional buildings, including a lack of baseline data on which to base judgements relating to energy improvements.”

2) lack of a tailored retrofit delivery structure

“There are good opportunities for the development of safe, robust, energy-efficient and cost-effective retrofit measures for many areas of traditional buildings. However these will have to be developed on a different basis and structure from some current Green Deal proposals.”

3) lack of dependable guidance

“There is a lack of connection between high-quality research intelligence and the guidance documents which inform retrofitting procedures.”

The report explores the current understanding of the following with respect to traditional buildings:

  • Heat Loss
  • Moisture
  • Modelling and Monitoring
  • Ventilation and Indoor Air Quality
  • Overheating
  • Thermal Bridges
  • Airtightness
  • Existing Guidance (Regulations and Certitification)

It concludes that existing financial and energy payback models are flawed as existing heat loss through the fabric is often less than contemporary models assume for pre-1919 builds.

It calls for a more flexible Green Deal that would value repair work and less mainstream improvements too, such as the repair of shutters and addition of secondary glazing behind existing windows.

It recommends better models for traditional buildings that, for example, take into account the effects of driven rain, location-specific weather data and improved understanding of moisture mechanisms.

In short, the report suggests the current building industry is some way short of a full understanding of the performance of pre-1919 homes both before and after retrofit. More research is required.

Fortunately STBA have a tool in development which may plug some of the gaps in understanding. It is under trial use already and early signs are that it will enjoy the backing of both DECC and the Green Deal.

See the STBA website for more.

Also see:
Gap analysis study: Performance and Energy Efficiency of Traditional Buildings