The Energy Information Administration has just released two compelling statistics on housing and efficiency. As the chart below shows, U.S. homes built between the year 2000 and 2009 were 30 percent bigger than before 2000. But those households only consumed 2 percent more energy. 

That's both a good thing and a bad thing, depending on how you look at it. On a positive note, it shows that efficiency efforts are working. On a more pessimistic note, it means that our love for big homes is cancelling out any net gains.

As EIA points out, homes built between 2000 and 2009 use 21 percent less energy for space heating. That's because heating equipment is getting more efficient, building codes are getting stricter, and construction techniques are keeping pace. It's also due to geographic shifts as more than half of new homes are built in the South.

However, those Southern homes are creating more demand for air conditioning. They're also more likely to host a range of new gadgets and appliances -- increasing energy use by 18 percent over older homes. The result is a very slight increase in total energy consumption in new houses, even though homes are one-third bigger than they were a decade before.

After the collapse of the housing market in 2008, many experts predicted that the era of the McMansion was over and that the size of new homes built in the U.S. would continue shrinking. Indeed, after the peak in 2006 and 2007, the size of new homes did fall slightly -- mostly because it was harder for Americans to pay for them. 

However, that trend is reversing as very wealthy Americans who can afford to build new homes start building them. Even though builders were putting up fewer houses in 2011, those residences were bigger on average than homes built during the peak of the housing bubble. If that continues, efficiency gains made through technology improvements and building standards aren't going to make a major dent in the new housing sector.

Tags: construction, energy, energy efficiency, housing, housing bubble, recession