A lot has changed in 40 years. Disco is now retro, flares are set off at football matches, and the Good Life is a vague aspiration, rather than a TV show. All this you already knew.

But did you also know that carbon dioxide emissions from heating, lighting, and electrifying an average UK house have almost halved in that time?

A new study by design consultancy Cambridge Architectural Research, done for the Department of Energy and Climate Change, sheds light on how household energy use has changed over the last four decades.

The analysis shows some interesting trends in home heating, gas and electricity bills, and carbon dioxide emissions. To try and make the figures a bit more real, we’ve put them in some cultural context:

– Figures refer to the year in question, not a decadal average.
– All monetary figures are in 2011 prices.
– Household temperatures are also affected by outdoor temperatures, which vary year to year.
– The images are not necessarily representative of average UK households.

As you can see, households are paying more for energy now than in 1970, and a lot more than they were 10 years ago. That’s largely because the amount companies pay for fuel to run power stations – mainly gas – has spiked sharply in recent years, with the extra cost passed on to consumers.

Higher energy bills mean households are having to tighten their belts, which could explain why people don’t crank up their heating as much as they did in 2000.

But at the same time, houses have become more energy efficient, meaning homes can be kept warm without using as much energy. Insulation improvements, advanced heating systems, and more efficient appliances mean people get more for their money, and reduces each house’s carbon dioxide emissions.

Gains in household energy efficiency are offset by population growth and a trend towards less cohabiting, however.

There are about 10 million more households today than there were in 1970. As such, UK households collectively use about 25 per cent more energy than 40 years ago. So while individual households are using less energy than ever before, overall demand for energy continues to soar – undercutting the effect of more efficient homes on the UK’s emissions.