Green building measures are providing substantial benefits in the United Kingdom’s housing sector. From 1970 to 2011, the average energy use per household in the U.K. has dropped nearly one fifth despite a massive expansion in central heating and appliances, according to the U.K. Housing Energy Fact File 2013, published yesterday by London’s Department of Energy and Climate Change and commissioned from Cambridge Architectural Research. In addition, the average internal temperatures in U.K. homes are 4 C (7.2 F) warmer than they were 40 years ago, offering residents better comfort.
The report shows that overall household energy costs in the U.K. rose by less than 0.4 percent per year on average, for a total increase of 16 percent over the past four decades. However, during this time more than 8 million homes were added to the U.K.’s building stock, and the average household size diminished. This increase in stock but decrease in home size produced an 18 percent decrease in average energy use per home, dropping from 23,800 kilowatt hours in 1970 to 18,600 kilowatt hours in 2012.
How does the United States compare? “We are seeing the same pattern here in the U.S.,” says Ed Mazria, founder and CEO of Architecture 2030. “Even though we’re adding approximately 3.5 billion square feet to our building stock each year, our energy consumption has actually gone down since 2005 thanks to the combination of better building strategies and greater efficiency in materials and equipment.”
Mazria credits increased insulation, better glazing, and new efficiencies in heating and water equipment and appliances for part of the turnaround. Lighting is significant too, as compact fluorescents and LEDs use only a fraction of the electricity used by incandescent bulbs. Building design that incorporates passive strategies such as solar orientation, natural ventilation, and appropriately colored roofs are also critical. “We are getting smarter across the board in how we design homes and buildings, and in more efficient materials, building shells and equipment,” Mazria says. “To obtain the kind of reductions in energy consumption and emissions we have today, we are getting better at everything.”
Although carbon dioxide (CO2) emissions were down overall in U.K., the study acknowledges there was an uptick in coal-fired power in 2012 that is not included in the emissions statistics (which were compiled from 1970 to 2011). In 1970, two-thirds of the U.K.’s power came from coal, but by 2010 it had dropped to one-third of the supply while natural gas became the main source for electricity. However, when the price of coal recently fell, the U.K. increased coal-fired power to 44 percent of its 2012 electricity generation.
Mazria saw this dynamic also play out in the U.S. “The reason we saw a 2 percent rise in CO2 emissions in 2013 was fuel switching in the power plant sector: when natural gas prices went up, plants switched back to less expensive coal to generate electricity for heat during the harsh winter,” he explains.
With 27 million households in the U.K., housing accounts more than a quarter of the country’s total energy consumption–costing £34 billion ($56 billion) a year—so the report’s positive findings about green measures are welcome news. Energy and cost projections are also bright for the more than 115 million U.S. households. Although the U.S. is projected to add 60 billion square feet of building space from 2005 to 2030, efficiency measures are expected to save consumers $4.6 trillion from original 2005 projections, according to the U.S. Energy Information Administration’s Annual Energy Outlook for 2014. That’s not all, says Mazria, who adds that “if we simply use the most efficient off-the-shelf technologies available today, we could save an estimated $6.7 trillion, and reduce fossil fuel energy consumption incrementally to achieve carbon neutrality by 2030.”
All data provided by U.K. Department of Energy & Climate Change, the United Kingdom Housing Energy Fact File 2013.