In November 2015, the chief construction adviser to the government Peter Hansford published his recommendations aimed at restoring the credibility of solid wall insulation (SWI). The report “Solid Wall Insulation – Unlocking Demand and Driving Up Standards” provides a roadmap for the way the industry needs to go to improve standards and quality of work, embracing best practice and restoring consumer confidence that will stimulate the uptake of these measures leading to improving comfort, health and well-being as well as carbon reduction benefits.

The UK has a legally binding commitment to reduce carbon emissions from 1990 levels by a massive 80% by 2050. Accordingly, the Construction 2025 strategy has set the ambition of achieving a 50% reduction in emissions across the built environment by 2025.

Given that there are around 26 million existing homes in the United Kingdom and over eight million of these with solid walls, adopting solid wall insulation as a solution for much of  existing UK housing stock makes good business sense. The UK Green Construction Board commissioned Peter Hansford to carry out this review. Its purpose is to leverage the latent possibilities in the construction industry to unlock innovation and increase demand for solid wall insulation.

Benefits derived from treating properties with SWI, in addition to the carbon reduction benefits, include -improving comfort, health and well-being; supporting fuel security by reducing overall energy demand; addressing fuel poverty;improving fabric and reducing maintenance costs; regenerating neighbourhoods; and contributing to GDP and tax revenues. The economic case for the energy efficiency of the UK housing stock is also strong.
However, current demand for SWI is depressed for a variety of policy and technical reasons. At the same time, SWI has developed somewhat of a poor reputation due to numerous examples of inadequate installation and poor workmanship. The report considers that if  SWI is to be promoted as an effective retrofit solution, these areas need to be addressed with urgency. The Green Construction Board is therefore keen to see increased demand for SWI and better standards of design and installation, so as to significantly reduce carbon across the domestic sector of the built environment.

With so many property archetypes existing, there is no single solution that would apply to all properties. This adds to the confusion by householders of what is the correct solution for their individual properties.

To make matters worse, the building physics for some types of property is not widely nor perhaps fully understood. This has resulted in many instances of an incorrect solution having been applied, which in some cases has caused damp, mould or poor air quality. Little wonder then, the reluctance of homeowners to spend money retrofitting their properties if the outcome cannot be assured.
To overcome these problems, a higher level of expertise is needed in assessing the correct solution for a particular property and in ensuring that it is installed properly.
The top 12 domestic property archetypes in the UK account for approximately 15.5 million homes. They represent around 60% of the total UK housing stock and 57% of its greenhouse gas emissions. Of these 15.5 million homes, around 3.5 million (some 23%) are suitable for SWI. SWI therefore has the potential to benefit a significant number of homes and play a key role in reducing greenhouse gas emissions from the UK domestic housing stock.
From this group of 3.5 million homes suitable for SWI, 75% are owner occupied (2.6 million); 10% are owned by Local Authorities or Housing Associations (340,000); and 15% are private rented (550,000). Nearly 1.2 million of these homes (34%) are categorised as containing ‘vulnerable households’.
The report offers recommendations to address the issues above, and proposes:

• Taking a co-ordinated and holistic approach to insulating solid wall homes;
• Policy measures which Government may wish to consider;
• Focusing research on areas that are not fully understood;
• Review and revision of standards and measures for statutory compliance;
• More robust accreditation of assessors and qualified installers;
• Development of guidance for assessors, designers, supervisors and customers, in language appropriate to themselves;
• The role of a Retrofit Co-ordinator;
• An awareness campaign with a simple message, so as to increase uptake;
• The creation of a Retrofit Hub as a technical centre of excellence; and
• Leadership arrangements for making these recommendations happen.

The report also contains a number of case studies of different property archetypes.

Get the full report

Additional article “Retrofit Coordinators to be mandatory for all SWI projects” – CoRE