The Government’s Green Homes Grant Scheme is turning from a headlining grabbing announcement from high profile politicians, into a scheme whose detail is being ground out by civil servants, regulators, and industry gurus. There are a group of very 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 irreparably stuff people’s homes up. I say good luck and best wishes to everyone involved.
Homeowners must understand the implications
This blog is not aimed at applying further pressure to the architects of the emerging scheme. Our reservations in regard to moisture and retrofit and the need for quality are well covered in previous articles. Instead, we want to start to highlight the need for homeowners and the recipients of the vouchers to be engaged and understand the implications of what they are about to do to their homes.
Insulation is designed to very significantly reduce the rate of uncontrolled air movement through a building. This has the effect of preventing both the escape of heat and just as importantly, moisture from the occupied building.
Moisture imbalance can lead to expensive complications
This is all good as long as the insulation does not cause a building or elements of the building that were in moisture balance, to become imbalanced. Moisture imbalance results in rot, mould, failing wall finishes and the deterioration of the buildings’ fabric. Things that can be complicated and expensive to fix.
We have written before about how cavity, internal and external wall insulation changes a building and how it deals with water. An understanding of this is important not only to the designer of the retrofit insulation scheme, but also to the building surveyors who will subsequently inspect insulated buildings, and to the people who own and use buildings.
Dealing with moisture generated within the building is relatively simple. Improving the ventilation system is acknowledged by almost everyone as a fundamental element of any retrofit insulation scheme. What must also be understood is that these augmented air extraction systems must be maintained for the lifetime of the building. Failure to repair service and renew ventilation systems over time will result in expensive and unhealthy moisture imbalance.
Understanding the principle of ‘fabric first’ is key
The principle of ‘fabric first’ when considering retrofit insulation is taken from the highly regarded PAS2035. The principle being that insulation must never be applied within or over defects in the underlying building fabric. This mantra is hugely important, and we would urge homeowners to insist on detailed pre-installation checks on the property before any insulation is applied.
Moisture related issues, blocked cavities, defective guttering, high ground levels, etc., should never be overlooked. In our experience the risks of calamitous, costly, and highly damaging issues with damp and timber decay are hugely increased when underlying defects are ignored or covered up.
It must be remembered that retrofit insulation introduces new layers of material that can mask dampness, conduct, or hold water, or even prevent the transition of moisture by drying. This is fact and though it should not put people off insulating their homes, we have to understand the increased importance of maintenance and keeping water out of the structure.
Take cavity wall insulation for example. Cavities filled with air are good at stopping internal walls getting wet even if the outside leaf of masonry is in poor condition. Fill it with insulation and even the best product installed by the most diligent installer can become wet and allow moisture transfer. This sort of direct correlation between what once may have been considered minor defects, and the greater significance of water ingress to the retrofitted buildings can be seen in all forms of retrofit.
We must take caution and not get swept up by the Green Homes Grant
So, what is the answer? The Green Homes Grant is coming, and it will hit us like a tidal wave. We must try not to get swept up by it, take time to ensure that buildings are in a fit condition to accept insulation and that owners and occupiers understand the long term implications of what they are doing to their homes.
Experts know the consequences of poorly designed, badly executed, rushed, and ill-maintained retrofit, so let’s make sure this is communicated to the hundreds of thousands of people that will soon be applying for a voucher. Good clients that understand what they are buying is good for everyone.
Educate and inform the public
We urge Government, industry, regulators and the media to start a campaign of public education and help them understand that energy saving measures are to be embraced, but retrofit affects the way the building works forever and the way we look after them must also change forever.
We all want greener homes, but that greenery must not be allowed to grow on the walls of our kids’ bedrooms.
Note for PCA members
We would implore members to consider the very important role that we can play to ensure buildings are not adversely affected by retrofit measures. Make contact with insulation companies, contact clients, and promote good moisture diagnostics and ventilation improvements that are based on need and compliance with Part L.
No insulation should ever be applied to a damp building. We can all help get this message across to our domestic and commercial clients.
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