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Does Energy Efficiency Only Matter for New Build Properties

Clearly regulations for energy efficiency relate to both new build and refurbishment but should it? Regulations for acoustics take into account new build properties and the difficulties of existing buildings so why don’t we for energy efficiency?

When we get to the “other side” of Coronavirus the way we come out will be different, we will need to develop a “new norm” as we will unlikely go back to the “old norm”

The almost biblical effect of Coronavirus will have rebooted the way we think about various things such as- what’s important in life, the benefits of family life, appreciation of what we have, how we can do business more efficiently, not be as wasteful and the effects of climate change. We are already seeing the effects of the latter in the waters in Venice as we spend less on travelling.

So is it time for the government to look at the existing housing stock and how their efficiency can be improved? The same way as Part E and Section 5 recognise, instead of hammering the easy target of new build properties where the targets set provide the new minimum requirement to design down to as cheaply as possible rather than a worse case minimum.

As stated, Part E and section 5, acoustic regulation are considerate of the difficulties of trying to design existing buildings with its existing issues to the same as performance levels of new build built from scratch. With acoustics, even in refurbishment the acoustic measures will invariably be better than before but with thermal improvements there could be knock on effects such as structural damage due to hidden moisture issues from trying to improve the buildings energy performance. Therefore, a good understanding of HAMM (Heat, Air and Moisture Movement) are critical to get the balance of improved energy efficiency with moisture issues.

The government aim to reduce green house emissions by 80% by 2050 requires a change of emphasis which goes away from just new build to looking at existing housing stock. This would provide not just reduced emissions but potentially less burden on the NHS and lower living costs to heat homes. We must be considerate of what the placement of insulation would have in old homes, one issue being solid wall homes.

Solid walls have been a good choice through the years for a country that lives in a climate where there is a lot of rain. These walls can be built thicker depending on their exposure to rain to reduce the amount of water penetrating the external wall. These walls were traditionally built of stone work in such a way that they also “breathed”, thereby drying the walls when the climate allowed which can be effective but not very efficient thermally.

According to NIA (National insulation Association) the current housing stock in the UK stands at 24.5 million dwellings. Of these 6.6 million properties have solid walls which represent 31% of the total housing stock, 48% of the 326,000 high rise flats in England have solid walls. These solid walls are deemed hard to treat in that they cannot benefit from the easier energy efficient method of cavity fill. They can only be treated internally with internal wall insulation (IWI) or with external wall insulation (EWI). Both of these options come with the benefit of potentially improving the insulation levels in the dwellings but with more difficulties especially internally applied insulation.

With IWI, more does not always mean better and there is a real case for balancing energy efficiency with good moisture control and understanding. In its most simplistic form, more insulation (thicker) will come at the expense of space internally, in some cases making double bedrooms into singles and singles into box rooms. So, we strive for more energy efficient insulation to reduce the thickness required which can be an efficient option but this can compromise the vapour permeability of the wall and reduce its “breathability”. In most cases the strive for more efficient thermal insulation at a lower thickness needs to compromise the vapour permeability and the constant balancing of these factors becomes an ever-increasing conundrum, until recently.

Now you can balance improving the thermal efficiency, decrease water absorption and maintain the intended breathability with the introduction of nano technology called Spacetherm insulation. The Spacetherm® insulation from A Proctor Group gives high levels of thermal insulation with a low thermal conductivity of 0.019 W/mK while still being breathability and an exceptional levels of water repellence. Solid wall properties can be transformed with thin insulation in term of green gas emissions yet not at the vast reduction in room size.

The Spacetherm WL board comes in just 13mm thickness including the 3mm MgO hard wearing surface which is adhesively bonded to the wall. This can reduce a solid wall U value from 1.5 W/m2 K (and in some eyes 2.1 W/m2 K) to below 0.7 W/m2 K. This is halving the heat loss through a solid wall at around half an inch thick! If the government were to relax the conversion levels to this level then nearly a third of the UK existing housing stock can reduce its heat loss dramatically without major disruption to properties whilst still maintaining the structural integrity due to the breathing wall and less risk of built in moisture issues from vast changes in structures temperature and therefore in built condensation problems.

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