SUSTAINABLE REFURBISHMENT
There are 2 ways of going about energy efficient refurbs: scientific and intuitive. The science is usually done on larger scale developments or by larger organisations such as social housing providers or government agencies. So individuals do not have to get involved in much science. For example, studies show that 270mm is the optimum thickness for loft insulation, but the manufacturers are supplying this thickness and it is readily available at builders merchants and diy stores, so use the science sparingly
Consider how much premium you are prepared to pay for materials with sustainable credentials-locally sourced, low embedded energy, recycled or recyclable materials. For example again taking insulation, you can pay a premium to use natural, sustainable products such as sheep’s wool or recycled newsprint, or go for the industrial product.
Consider capital cost vs cost-in-use. Grants and feed in tariffs can skew the decisions.
Priorities: It may not be possible in a single dwelling to provide for all the energy needs on site, but increasing insulation and airtightness and installing diversity will reduce dependence on fossil fuels. Micro generation delivers energy from renewable sources, but also reduces dependence on centralised supply from the grid which is subject to market forces and sometimes political interference. Also consider whether you want to be an eco warrior or just have a comfy life!
Here’s the thing though: keep refurbishment measures as simple as possible: maximum insulation, attention to airtightness and controlled ventilation, together with straightforward heating equipment and easy-to-use controls, are the priority.
TEN THINGS TO CONSIDER:
DOUBLE GLAZING: double glazing units fitted into timber frames without proper attention to drainage and ventilation cannot be expected to last as long as they should. Locally made ‘joinery shop’ timber sashes do not usually have sufficient rebate depth. To have a reasonable life expectancy, sealed double glazed should be properly fitted in the appropriate frames, ventilated and drained.
LIGHTING: Use low energy lamps of course!. Choose LED fittings carefully-some have poor colour rendering; consider a sun tube on an internal landing to bring in free sunlight; consider switching lights separately so that you can mix and match lighting for different situations.
AIR TIGHTNESS AND VENTILATION: “Build tight-ventilate right”. In practice it is difficult to make an old property airtight. Extract moisture at source in kitchen and bathrooms; use humidistat to control bathroom ventilation; open a window to get rid of smells; heat recovery is not cost effective for small domestic situations. Extract fans with mag lev bearings do not make the noise conventional fans make when the bearings start to wear out.
INSULATION; Make sure electric cables are not buried under loft insulation. Insulated curtains increase comfort and reduce heat loss especially on large areas of north facing glazing. If you have slid external walls, it may not be possible to insulate them all, so insulate what you can.
RAINWATER HARVESTING: a full scale rainwater harvesting installation is probably not appropriate to a small refurbishment but water butts and diverters are cheap.
SOLAR AND MICRO-GENERATION: Solar thermal will almost certainly make sense. You may not have enough roof area in a small house to make photovoltaics worthwhile, but consider the new feed in tariffs. A multifuel stove will provide diversity and is a really nice thing to have! Combination solar and PV panels called PV-T are apparently more efficient . Wind power-check the Energy Saving Trust’s calculator of their website to see if it is feasible in your location.
HEATING If we apply high standards to refurbishment, we would have to be looking at space heating and domestic hot water from renewable sources. Solar thermal on its own could over provide hot water. Consider underfloor heating with a ground source heat pump or PV-Ts.
PORCH: reduce air changes when opening and closing external doors.
DRAUGHT PROOFING seal gaps in floorboards and skirtings and insulate suspended ground floors.
WATER SAVING: use aerating shower heads and taps
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