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Is cavity wall insulation the right energy efficient home improvement for my property?

Cavity wall insulation is getting the kind of press that the window industry used to.

Thousands of people up and down the country were sold cavity wall insulation without a proper assessment of their property and its suitability for it, as an energy efficient home improvement.

The net result is that cavity wall insulation failed to deliver the levels of claimed thermal efficiency for thousands of homeowners but also and far more seriously, left tens of thousands with major damp and condensation problems.

Findings from a survey of more than 250,000 properties by the thermal imaging company IRT, found that far from delivering promised cheaper energy bills, cavity wall insulation had failed to work in a quarter of cases, had caused problems in half the homes - and some home owners had actually seen bills rise!

With more than six million properties having had the treatment since 1995, this suggests that as many as 1.5 million are affected.

Why cavity wall insulation could be a source of damp problems

Cavity wall installation isn’t our specialism – we don’t do it – but it makes a point about how energy efficient home improvements need to be approached with an element of caution and sensitivity to the fabric of the building.

Buildings need to breathe and in some cases - although by no means all - cavity wall insulation doesn’t let them. It can also act as a bridge between wet external walls and what should be dry internal ones, causing damp, mould and all of the problems that go with it.

This doesn’t mean that all cavity wall insulation companies are cowboys.  As with our own industry there are those that are professionally run and responsible – others that are less so. As with so many things in life, it tends to come down to the fact that you get what  you pay for and if something appears to be too good to be true, it probably is.

It makes doing your research before investing in cavity wall insulation critical.

Alternatives to cavity wall insulation

So if your property isn’t right for cavity wall insulation, what are your options? New windows and doors are a good place to start. Most properties will already have an adequate level of loft insulation, and if your home isn’t suitable for cavity wall insulation (or you already have it), energy efficient windows can delivers some sizeable energy savings.

According to the Energy Saving Trust, heat lost through windows accounts for around 25 per cent of the total energy lost from your home. 

This means that double or triple glazed units both deliver significantly improved performance over and above single or even older double-glazed units, delivering savings of up to £200 per year dependent on specification of new energy efficient double and triple-glazed windows playing an important part in reducing your energy bills alongside loft and wall insulation.

Energy efficient windows and doors

KJM Group supplies an extensive range of low maintenance and energy efficient windows and doors, throughout Hampshire, Dorset, and Wiltshire. This includes casement, tilt and turn and vertical sliding windows and doors in PVC-U, timber and aluminium and energy saving triple-glazed windows with U-values as low as 0.66W/m².K.

At 0.66W/m².K you have a Passivhaus Scandinavian standard product. It offers 40 per cent better insulation over our Window Energy ‘A’ rated double-glazed products, which are already incredibly energy efficient products.

The importance of adequate ventilation

Energy efficient windows and doors are designed to seal your property, they block out draughts and prvent the transfer of heat from inside your home to the outside but you still need to make sure that your property is adequately ventilated.

If you don’t release it, you get a build-up of condensation. Although this isn’t a problem in itself, this can lead to the growth of black mould, which can come with some potentially serious health problems, especially if you have children living within your property.

At its most basic, simply opening a window in a bathroom after showering, can make a huge difference to the build-up of moisture within your home. If it’s doesn’t do the trick you might want to consider installing extractor fans in high moisture areas, for example bathrooms, showers and kitchens.

Window trickle vents provide another solution, these allow a controlled, consistent and low level air-flow within your home, bringing in fresh air and removing stale moisture filled air. Good window installation businesses will raise this with you as part of the window design process.

We’re experts in windows, not cavity wall insulation but we do know that homes need to be ventilated and energy efficient home improvements need to be installed responsibly. The window industry has gone a long way to clean up its act. We expect the majority of responsible cavity wall installation companies to drive a similar broom through their own industry.

For more information on our range of energy efficient windows and doors call or email the sales team on 01264 359355 or sales@kjmgroup.co.uk