Green Homes Grant concerns over quality of work

Insulation in the roofspace of a house

The government’s new Green Homes Grant is due to be launched in England in September 2020. Under the scheme the government will fund between £5,000 and £10,000 towards qualifying energy-saving home improvements, which equates to around two thirds of the cost.

Details of the Green Homes Grant have not yet been provided but only accredited installers will be able to carry out the work. These installers will have to work to a specific standard and have robust consumer protection practices in place. 

However, there are some concerns over the quality of the work that might be carried out following on from previous failures to successfully upgrade cavity walls in homes.

As one of our surveyors, who is a qualified Eco-Surveyor, explains:

Cavity wall insulation is injected into the space between the inner and outer walls by drilling holes then injecting wool, foam or bead insulation. If the home insulation is done correctly, the home is made warmer and the homeowner can expect lower energy bills.

If it is done badly, it can lead to the walls becoming damp or even mouldy. This can often be the result of debris within the wall which should be removed before installation. Filling a cavity wall obviously means it no longer has a cavity, so damp can pass more easily from the outside leaf into inner leaf. 

Cavity wall insulation means installing a physical bridge between the inner leaf and outer leaf of the wall, upon which any moisture can be passed to the inner skin rather than fall down cavity, where it will escape through the ground or through weepholes.

The other main cause of damp following cavity wall insulation occurs if there are cold spots caused by the uneven distribution of the insulation. The resulting cold spots on the external walls where insulation is not evenly spread then attract condensation caused by internal moisture within the inhabited environment condensing on the cold spots of the external walls.

Homes may be covered by the Cavity Insulation Guarantee Agency (CIGA) which is industry-funded but not a regulator. The body says it provides a 25 year guarantee for cavity wall insulation fitted by the UK’s registered installers. However, some homeowners have found that the guarantee does not cover the full cost of removing the insulation and repairing any damage.

It is estimated that retrofitted cavity wall insulation has failed in at least 800,000 of the 13 million or more UK homes in which it has been installed.

Read more about cavity wall insulation: Cavity Wall Insulation – A Guide

Get in touch with a Property Surveying Chartered Surveyor if you require advice on condensation, damp or mould issues caused by cavity wall insulation within your home or are considering having cavity wall insulation installed.