The method of dealing with poor performing homes without cavities to fill with insulation has come under scrutiny after a number of high profile projects have had to be extensively modified to cope with moisture and ventilation problems.
Sub-standard installation can create ‘thermal bridges’, which result in condensation. In a recent study of 2,000 SWI installations, all had at least minor issues – and on some they were extremely concerning. A range of 126 types of ‘unintended consequences’ were identified, with 27 of them being classed as ‘severe’.
Claire Curtis-Thomas, chief executive of construction product certifier BBA, said a ‘significant percentage’ of SWI inspections have revealed a technical failure of insulation. ‘We haven’t found a product that fails, but we do find lots of installations that fail,’ she said.
The event, organised by Sustainable Homes and hosted by Shadow Energy Minister Dr Alan Whitehead at the House of Commons, saw a consensus emerge after a vote was put to attendees, from social housing and the supply chain. Most, mainly from housing associations and the supply chain, agreed that assessments of SWI installations should cover one in 10 homes. The group also felt that Energy Company Obligation (ECO) funding should only be released following such checks. ECO is currently being reviewed by the Government.
The input comes as Peter Bonfield reviews energy efficiency policies on behalf of Ministers, and in the light of the Hansford Review, also commissioned by the Government, which looked specifically at solid wall insulation.
Curtis-Thomas advised organisations commissioning the installation of SWI to focus on the quality of work and make sure guarantees were in place and carry out a stock inspection before they expired.
The event benefited from expert contributions from others including Lynne Sullivan, co-founder of sustainableBYdesign, who chaired the discussion and sat on the expert panel for the Hansford. ‘We have one of the most difficult housing stocks in Europe,’ she said. ‘People’s health and wellbeing is at stake as well as national carbon emissions.’
Andrew Eagles, managing director of Sustainable Homes, said that SWI ‘has great potential to improve energy efficiency’, as walls contribute to a third of a home’s energy inefficiency, compared to 14% for a boiler.
Also on the panel was Noel Brosnan, director of asset management at Octavia Housing, who urged social landlords to ‘get out there and do something’ about retrofitting their homes with SWI. ‘What is the point of sitting there and wringing your hands?’ he asked. ‘Are the technical solutions 100% risk-free? No – but what is?’
Following feedback from this event, Sustainable Homes is organising a workshop aimed at housing providers and the supply chain – please get in touch to register your interest.