This “impossible” house generates more energy than it uses

Alan Martin July 16, 2015

In 2006, the British government set itself an ambitious target: that all new homes should be carbon-neutral by 2016.

Last week the Conservative government scrapped the target, with the BBC noting that chancellor George Osborne once described a cost-efficient, carbon-neutral home as “impossible”.

With immaculate timing, a team at Cardiff University has proven once again that MPs regularly overestimate their expertise. The three-bedroom house pictured above cost £125,000 to build, and generates £175 in surplus electricity exports for every £100 on electricity used.

That’s an impressive statistic, but the real clincher is the cost of the house. At £1,000 per square metre, it narrowly squeezes into the price range for social housing, which is currently set between £800 to £1,000 per square metre. This could drop even lower if a number of houses were built at the same time and, according to project lead Professor Phil Jones, would potentially slash the overall cost by 20%.

How does the house accomplish its energy-saving feats? With a combination of photovoltaic – that’s solar, to you and me – panels and battery storage. These run the heating, ventilation and hot-water systems, in addition to the main electrics that power all appliances, LED lighting and a heat pump.

“We save money and space by making the roof itself of photovoltaic panels and by dispensing with radiators and making the air collector part of the wall,” explained Professor Jones. carbon_house

Since the house relies on solar energy, it still needs to “import” electricity in the winter months. However, the researchers found that even taking into account the variable Welsh coastal weather, the house would more than make up the difference in summertime.

We spoke to Kim Bryan from the Centre for Alternative Technology, who welcomed the low-cost breakthrough. He cited the project as proof that “housing can be affordable, built quickly, help reduce carbon emissions and save the inhabitants money”.

“The next stage for zero-carbon housing development is to ensure that, as well as being energy-efficient and generating energy through renewables, materials used in construction have low-embodied carbon and are of low toxicity – factors that are often overlooked in sustainable design,” Bryan added.

You’d hope that this news might spark a government U-turn and see the zero-carbon housing target reinstated – don’t hold your breath. A government spokesperson told the BBC: “The government is not proceeding with the zero-carbon buildings policy and will instead give developers the time they need to build energy-efficient homes required by recent changes brought in during the last parliament to building regulations to improve efficiency.”

Still, just because the UK as a whole is slightly backward-looking in this department, doesn’t mean devolved government can’t pick up the slack. Professor Jones remained upbeat: “It was disappointing to see Osborne scrap the plans. But the devolved Welsh, Scottish and Northern Irish governments can set their own building standards.”

“One reason we built this house was to demonstrate to builders that you can meet the standards at an affordable price with off-the-shelf technology. The housebuilders could do it too if they wanted to.”

Here’s hoping that the project has inspired them to do exactly that. You can watch the University’s own tour of the house in the video below.