Is your home in a fit condition to be upgraded by a government Green Homes Grant?

The government is rolling out the £2 billion ‘Green Homes Grant’ at the end of September, providing homeowners in England up to £10,000 to install insulation systems into their homes to save energy.

In principle, the scheme has been rolled out with good intentions. It has been designed by civil servants, regulators, and energy/insulation advisors. This is a group of well motivated experts who are working under intense pressure to turn an emergency job creation scheme into something that delivers energy savings, eliminates corruption and doesn’t result in irreparable damage to your home.

Photograph showing wet cavity wall insulation.

The ongoing issues due to incorrect cavity wall insulation, resulting in extensive dampness are still rolling on. Retro fit cavity wall is now common in millions of properties across England. So are the problems caused by incorrect specified schemes, due to the lack of correct surveying. This has resulted in mould, dampness and fungal decay affecting properties. Along with the health issues created by a poor quality internal enviroment.

The purpose of this article is not to dismiss or advise you not to improve the energy performance of your property. But to inform you of the implications of installing insulation and draught proofing without having a correct inspection undertaken, to ensure it is suitable both in construction type and condition. You will be changing both the design and enviroment within the property so there is no one stop solution. You may be fit and healthy, and able to run a marathon. But should you change the circumstances by placing a polyethene bag over your head, your run is likely to become short and result in complications. Your home is no different. Changing the way it was designed and adding additional layers without understanding the implications can result in your property becoming defective and you becoming unwell. The government scheme does not include a provision to correct the defects occurring to the structure and enviroment affecting your property as a result of the installed systems. Insulation is designed to significantly reduce the rate of uncontrolled air movement through a building. This prevents both the escape of heat and just as importantly, moisture from the occupied building.

When you take a shower, the walls become wet due to a combination of increased moisture vapour (steam) and the surfaces falling below dew point (temperature at which moisture vapour turns back to liquid). We all know how mouldy the bathroom can become if not effectively ventilated. Now imagine this through the whole of your property if it’s not effectively ventilated.

Photograph showing condensation on a surface at dew point

Photograph showing fungal decay (wet rot) under a floor as a result of blocked subfloor ventilation by cavity wall insulation.

The moisture vapour you see is not the danger as you can easily address this by opening a window. It’s the moisture vapour which has entered the voids of the property. Remember when you were at school and the science teacher informed you of Pascals law, ‘pressure is equal in all directions’. As the internal environment is heated, the air will expand and move the moisture vapour into the unheated voids, which have a lower pressure, presenting a risk of mould forming along with the decay of the installed timber.

The principle of correct inspection of the property when considering retrofit insulation is taken from the highly regarded PAS2035.

The principle being that insulation must never be applied within or to a wall with defects in the underlying building fabric. This is hugely important, and we would urge homeowners to insist on a detailed pre-installation survey on the property by a suitably qualified surveyor before any insulation is applied.

Moisture related issues can come in many forms. Blocked cavities, defective pointing, guttering and high ground levels, which should never be overlooked. The risk of doing so can result in costly and highly damaging  damp and timber decay which are hugely increased when underlying defects are ignored or covered up, by installing new layers which will prevent the structures drying down and in some cases introduce further water into the structure.

If you are considering taking up the government offer to install energy saving measures into your home through the Green Homes Grant, then have a survey undertaken beforehand and save your property turning green from mould!

Photograph showing fungal decay (wet rot) under a floor as a result of blocked subfloor ventilation by cavity wall insulation.