The price of failed cavity wall insulation – for homeowners and industry

Steve Hodgson, chief executive of the Property Care Association, on the epidemic of failed cavity wall insulation retrofits, with a photo gallery of failure here.  

As the lid slowly comes off the well intentioned but ill-conceived Green Deal and Eco schemes, we should try to consider the fallout and what this really means for those who have been sold the benefit of subsidised wall insulation.

The retrofit insulation industry has faced the same seemingly intractable problem many times: insulation providers struggle to convince people to spend their own money on good-quality, well-designed and properly installed energy saving measures.

So for almost two decades, the retrofit insulation industry has grown quickly and then contracted with the ebb and flow of government inspired subsidy. The promise of vast amounts of funding delivered as grants has created a “gold rush” mentality among speculative contracting organisations.

As one scheme starts, they know they must work hard to grab as big a share of the pot as quickly as possible. The latest scheme is likely to end on a fixed date and they will probably have to shrink fast, dump staff and hang on as one funding stream dries up and another goes live.

Quality of installation, the building’s suitability and the particular needs of the site become secondary considerations. Volumes, speed and meeting demand and making money quickly become the drivers – and the pursuit of volume sales is seldom a reliable driver of quality.

A lack of quality in both the installation and the design of retrofit insulation is inevitable in the circumstances. It is the result of the false market created by government intervention, the push to spend cash, grant systems that reward volume not quality, an almost total lack of verification and quality assurance.

Last year, we asked members to submit evidence on the kind of problems they’d encountered, to help update the wider membership on how they should be advising property owners – photos and details of three homes are posted here. 

But these systems came about despite the fact that customer care and quality were a primary consideration for the legislators when the Eco and Green Deal schemes were being built.

So where does the blame lie? In our view the underlying problem sits with the funding models. The push to spend, and the drive for volume, is never going to create a sustainable, quality-led industry that promotes trust, incentivises research and long-term investment, or the development of a sense of social and corporate responsibility. 

But let’s look in more detail at the problems our members are discovering when called in to properties. When retrofit cavity wall insulation is installed to a property that is located or built in a way that means it is not suitable to have the cavities filled, or if the work is undertaken incorrectly, the first and most obvious sign of a problem is almost always internal dampness.

Most homeowners will be blissfully unaware if cavity wall insulation has not been installed correctly. They will not know if it is over-packed, under filled, where it has slumped, where areas have been missed, vents have been blocked or obstructions missed. This is because even though the energy savings won’t be as advertised, there is no obvious sign of any defect.

But those that are aware of a problem will almost certainly have been put on notice by the appearance of dampness within their home. Cavity wall fills should generally be part of a suite of measures to improve thermal performance. However, all too often it’s the only measure used. Where cavities are discontinuous, or are crossed by solid elements such as floor slabs, or parapets, “cold bridges” can be left.

Before the insulation was installed the temperature difference between these bridges and the wall may have been relatively small. After the cavities within the walls are filled with insulation, these uninsulated elements may be significantly colder than the surrounding walls. This, coupled with the effects of a draughty house, can create the right conditions for condensation and mould, often where it’s not been seen before.

We have also seen a growing number of properties where no defects exist with the building or the new insulation, but owners are reporting new problems with damp. In these instances, it has been found that the insulation has stopped both warm air and moisture escaping. Without reintroducing air exchange through controlled ventilation, the wet air has nowhere to go. Subsequently the humidity levels rise and mould growth is almost inevitable.

Nothing set out in the examples above is particularly insightful. Every link in the chain of events has been fully understood for decades. In fact, a great deal was done to try to promote responsible and accountable cavity insulation work. Registration and certification schemes became a requirement for many contractors, warranty schemes became a mandatory requirement of the consumer offering and codes, protocols and standards were written to offer a framework for governance.

Unfortunately, however, many of the schemes grew too fast. They were unpoliced, unaccountable and in some cases inadequate for the situation.

In 2010, the PCA published a “white paper” that identified the total absence of design liability in these retrofit insulation schemes. It was our view then, as it is now, that too much emphasis is placed on the theoretical performance of the insulation. What is needed are professionals to assess the property and design the best possible energy saving measures that are commensurate with the style, condition and occupation of the building – not salesmen with computer models motivated by the need to secure a job.

Another pitfall that the legislators attempted to close out was assuring the quality of the technicians installing the product. Unfortunately, no one stopped to ask if the building and style of occupation was right for the kit the firm could sell, or what happens if good technicians, paid on results and with little by way of quality control, are released to do a job that is all but invisible when it is finished.

The rise of opportunistic, insulation removal companies is another symptom of a developing problem. It is true that in some circumstances the removal of cavity fills is the right thing to do but this conclusion must be based on fact, evaluation and knowledge. It is often possible to fix the building, the ventilation or the insulation. Removal of insulation can only be justified if the evidence dictates it.

We take no satisfaction from the fact that we predicted the current situation. In fact, we now think that we massively underestimated the scale and speed at which problems would develop. That said, we have not sat back. We have worked hard to promote the skills, knowledge and understanding that will be needed to inspect, diagnose and remedy the damp problems that are now being reported by homeowners, tenants and landlords across the country.