News – A Green Upgrade for a 1990s Home

It goes some way to indicate how rapidly Building Regulations changes are improving the energy efficiency of new homes built in the UK, that one of the strongest advocates of green improvements to existing homes lives in a house that was built just over a decade ago.

Paul Moult and his wife Monica live in a house they describe as being “the sort of house that much of the population lives in.” Situated on a pleasant modern housing estate on the east side of Worcester, the three bedroom detached home, built in the late 1990s, wouldn’t be the first type of home one would think would need a green makeover. But Paul and Monica were keen to explore the energy efficiency of their own home as part of a look at the green nature of their whole lifestyle and, once Monica became pregnant with their first daughter, Rachel, three years ago, decided that they would do something about their contribution to carbon emissions. “We really became aware of the type of things we could do when we spent a year living in [Monica’s native] Germany,” explains Paul. “There, practically all new homes have solar panels as standard and their overall lifestyle was at the time so much greener than ours. It spurred us on to thinking about green issues more and how our own home performed.

“The very first thing I did was change the boiler. I checked out our existing boiler on the SEDBUK scale (see and found out that our existing boiler was D-rated. We decided to upgrade to an Arated system boiler and it’s much more efficient.

ABOVE: The introduction of a new condensing boiler and solar thermal system (from Worcester Bosch 0844 892 3000) has transformed the efficiency of the home.

“We then started looking at the insulation levels in the house. The house was built with an aircrete block/cavity/brick structure — which was more than sufficient to meet Building Regulations back then [the 2002 changes to the Building Regulations effectively meant that the cavity would subsequently have to be filled with insulation to meet thermal requirements]

It certainly surprised me to find that as little as ten years ago cavities were not being insulated, so that was the first task we undertook. It cost about £200. Likewise, the loft insulation consisted of a blanket about 6” (150mm) thick. I wanted to bring it up to modern standards [Building Regulations now require around 270mm of insulation] and the installer simply added another 250mm on top of the existing blanket. With grants, the loft insulation cost about £180.”

Having been spurred on to find out more about solar panels after their experiences in Germany, Paul and Monica decided to install two panels on their south/south-west facing roof. The kit, which fully installed cost around £2,500, works by running glycol through pipes which heat up a second coil in the hot water tank. As temperatures in the panel hit 6° above the temperature of the water in the hot water tank, the pump kicks in and the glycol is heated up, in turn warming the coil. On the day H&R visits, standard outside temperatures are 18°C, while the panel is recording a temperature of 31°C. “We tend to have our water warmed to around 67°C” says Paul.

“It’s been really useful to have,” he continues. “Over the summer, we have only had to have the boiler on four times to provide extra hot water, which has usually been due to excess demand from us, combined with three or four cloudy days on the run. It works best in sunny weather, of course, but is absolutely fine in cloudy conditions. Even in winter it provides a third of our requirements.

“If I’ve got any advice for people considering solar panels it’s to make sure you get a big storage tank. We initially had a 150L tank and were finding that our solar panel would switch off at midday having heated all the water it could. It was a waste and so we upgraded to a 300L, very well insulated tank and now find that the water’s heated up well into the next day.” Paul’s now done some detailed calculations as to the savings from the work they’ve done, and while they never really did it to save money – it was more about reducing carbon emissions – they’re undoubtedly pleased with the result. “Even with rising gas prices we’re saving £300 a year on our gas bills,” he says.

Paul and Monica’s attention has now turned to power. “We’ve replaced all our bulbs with energy efficient alternatives – you can get a much better choice off the internet than at your local DIY shed – and all the appliances in the house are now A-rated. I had a mate who bought a new fridge-freezer at the same time as me and he was delighted because his was £40 cheaper. I told him that I’d make that money back in under two years!” he laughs. “It’s great to show how houses don’t need to be unusual or even old to justify an eco makeover.”

How the Efficiency Regulations Have Changed — and Why Even ‘New’ Houses Need Upgrading

The table, below, shows the evolution of U-value requirements as part of the Building Regulations. U-values are the main measure of heat loss through a material – the lower the U-value, the better – and are used as an indicator of energy efficiency. U-value requirements were first introduced in 1965 for walls and roofs and were later introduced for floors and windows. The table shows how the requirements have got even tighter in recent guises of the Regulations. Whilst it is true to say that we are now at a stage where U-values are so low as to be almost impractical to improve upon (the new 2010 Regulations make no changes to the requirements), the change between 1990 and 2006 is noticeable, particularly in relation to windows, walls and floors.