How to Give Your Home an Eco Makeover

Owning an old house has long been an excuse for using up lots of energy – and money – in keeping it light and warm. Not any longer. More and more renovators are taking advantage of a growing range of features that can be installed just as well into an existing house as they can be a new one — meaning that the traditional benefits of owning a new home, such as greater warmth and comfort – and lower energy bills – are now available to all. If you know what features make environ­mental as well as financial sense, modest investment at the planning stage of a renova­tion project can transform the way you enjoy the house for many years to come.

Eco makeovers, as they are known, range from simply adding extra insulation into the existing structure, to generating energy on site (usually through solar or wind power). They are also very much in the news thanks in part to higher prices, and also the fact that some pretty high-profile renovators are considering them. Perhaps the most well-known house on the receiving end of an eco makeover is the one in West London belonging to the new Conservative leader David Cameron. The redesign is being handled by architect Alex Michaelis (0207 221 1237), with a brief to make it perform as ecologically as any large brick Edwardian house can. “In a sense, David Cameron’s house is no different from any large five bedroom unlisted house of its generation,” says Alex. On the following pages we examine, with Alex’s advice, the best options.

Insulation: walls and loft

Around 40% of the heat that is lost from a home is lost through walls and the roof (the rest is lost through the floor and openings). This figure can be significantly reduced through the installation of simple loft insulation, which will cost between £130-200 to install and save around £150 a year in energy bills. Cavity wall insulation costs from around £135 to install and can save around £100 a year, while other forms of internal and external wall insulation cost a little more and have slightly longer payback times. Grants are available to further increase the financial incentive to undertake this type of project (see www.est.org.uk). “Insulation takes many forms,” says Alex Michaelis. “In my own house I have used insulation on both the inside and outside of my solid walls. With David Cameron’s house, because it will be a retrofit, I shall look at the possibility of adding insulation to the exterior of the walls. This might be possible on the back as it is in a terrace. At the front it is most unlikely because it will almost certainly be necessary to preserve the façade to keep the unity of the street. Therefore I shall probably look at ways of insulating the front of the house from the inside. Because the house has large sliding sash windows, they too will need to be insulated. Windows such as this can be insulated using brush seals as a means of achieving further air-tightness.” Most renovators, however, will want to install double glazing to reduce heat loss through windows, although timber would be more preferential from an environmental perspective than PVCu.

Other basic measures 

Lighting accounts for some 15% of an electricity bill. As each energy-saving light bulb saves some £7 a year, the benefits are potentially significant. On an even simpler level, ensuring that the new appliances you install are approved by the EST (look for the logo) means that, for example, on a fridge, you can reduce its energy consumption by two thirds — saving you £35 a year. A high-efficiency condensing boiler – particularly one that uses weather compensation control – will save you around £180 a year, while simply adding a jacket and lagging to the hot water cylinder and pipes will cover its outlay in a year. In particularly dark areas of the upper storeys of homes, a lightpipe might be an effective alternative to constant artificial lighting — light is captured from the roof and channelled down a mirrored tube. They cost between £200-700, depending on size and distance from roof.

Energy generation 

PV cells are perhaps the best known form of renewable energy and operate by turning solar radiation into electricity. The average UK home could generate around half of its own electricity through this method, providing it is used effici­ently and the home has a large south-facing roof. The greater the intensity of the sunlight, the greater the amount of electricity produced. The grant situation is currently confu­sed by the closure of the Clear Skies scheme in England and Wales, although in Scotland and Northern Ireland, grants of up to 50% are still available. Payback times on PV systems vary but are usually considered to be at least 10 years. Straightforward solar panels, which simply use the sun to heat water, tend to offer a much shorter payback period but do not enjoy the same grant status. Alex Michaelis is a great advo­cate of solar panels, particularly the evac­uated tube type of system. “With straight­forward solar thermal panels of this sort, I find that for a few hundred pounds you can easily get your money back in a few years because of the energy saved in heating your hot water,” he says.

Air circulation systems

The more substantial the structural elements of the renovation project, the more possible it is to install new, more energy-efficient central ventilation systems with heat recovery. The key to such systems is a heat exchanger, usually installed in the roof. This unit draws air from the moist areas of the house – the kitchen and bathrooms – and expels it through the heat exchanger. At the same time cold air from the outside is drawn in and warmed by the heat in the outgoing moist air. This warm air is then transferred to the bedrooms and living areas. The best heat exchange units claim to be able to recover about 90% of the heat that would otherwise be deposited outside. Installing all the ducting necessary to make systems like this work can be tricky and messy when the job is a retrofit. However, when this takes place in a period house that is having a total refur­bishment, it is unlikely to cause more distur­bance than there is already.

Reducing water consumption

Although water bills are still relatively cheap in the UK, last winter’s drought and this summer’s imminent water shortages have brought the focus back on to the way domestic properties use water — they currently account for up to 1,000 litres a day. All new builds are now required to install a water meter rather than pay a flat rate charge — and renovators interested in cutting their consumption would do well to follow this measure, as well as installing low-flush WCs and simple showers, rather than power showers — which use around 20 litres of water a minute. Even when compared to a bath which uses around 100 litres in total, power showers look very high in usage and those interested in conserving water should consider avoiding them. Fitting flow restrictors might be an alternative.

For those contemplating a more significant renovation scheme, the installation of a rain­water harvesting system should be consid­ered, as it can potentially reduce a household’s water consumption by around half. Rainwater harvesting systems, which cost around £3-3,500 installed, recycle rainwater and use it to flush toilets, water gardens and for the washing machine (www.freerain.co.uk).

Wind generators

Using the wind to produce energy is becoming a viable option for individual dwellings. The Swift Rooftop Wind Energy System is just 1.6m in diameter and costs around £1,300 — it generates around 1.5kWh of energy every time it turns. An alternative is the Windsave, which operates from the ground and requires a pole, but the manufacturers claim the £995 (plus 5% VAT) system can save a third of your annual electricity costs, giving a payback time of around five years.

Ground source heat pumps

The temperature at around 5-10m underneath the ground surface is at a constant level of around 10˚C. This heat can be extracted using the same technology as is used in domestic fridges to provide up to four units of energy for every one unit of electricity used to power the system. Installation costs are between £8,000-12,000, which is reduced somewhat under grants available on the new Low Carbon Buildings Programme. Most experts give the payback time at around ten years, and for renovators installation of a heat pump is only really practical if a significant amount of renovation work is taking place.

CASE STUDY:  Karen Hughes renovated using recyled materials

Karen Hughes stumbled upon her oak framed house, which had lain empty for 17 years, while walking in the woods. When she bought the property there was no running water, electricity or proper road access.

Eight years later and Karen has managed to retain all the character of her cottage – despite being advised by the builders to knock it down and start again – whilst adding numerous ecologically friendly features, as well as a new bedroom and a small extension for a new kitchen and bathroom.

Karen was keen that the cottage would be able to ‘breathe’ and says she “didn’t want to use materials that would end up getting into the soil”. Instead, she relied on natural, organic or recycled materials such as limewash and earth pigments.

An Italian cedar from the garden was felled and reused for stairs, kitchen worktops and interior window ledges, whilst another tree from the garden was planked up and used as flooring in the kitchen, the upstairs landing and as a surround for the bath.

ECO FACT: £271 million and 2.5 million tons of carbon dioxide are being wasted every year because 40% of the UK’s housing stock does not have cavity wall insulation.

CASE STUDY:  Remodelling with eco materials

Whilst renovating and remodelling her tired 1960s home, Donna Gray took the opportunity to incorporate a whole range of low-energy features.

Not only did Donna, a freelance designer, want to turn her home into a showcase for some of her designs, but she also wanted for the overall structure to be made energy efficient and to incorporate sustainable, eco-friendly materials.

Donna commissioned architect Duncan Baker-Brown for the project after being impressed by his approach to low-energy sustainable architecture.

Donna has chosen eco-friendly materials wherever possible, including non-toxic paints and Homatherm cellulose thermal insulation, made from recycled paper and jute sacking, which is treated with borax to make it resistant to decomposition and fire. This insulation also absorbs and diffuses moisture and therefore moderates humidity as well as temperature variation. A solar panel on the roof now warms water for the underfloor heating pipes, with a boiler providing back-up should it be required.

ECO FACT: 27% of the UK’s carbon dioxide emissions are accounted for by private housing.