Acton Real Estate Blog – Net Zero Homes

Wind turbines (Vendsyssel, Denmark, 2004)

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Housing in the News

By Victor Normand
Published: May 2011

This fall a group of student from area colleges and universities will be among 19 other collegiate teams competing to build the most innovative energy efficient solar-powered house in the US Department of Energy’s Solar Decathlon competition.  The event began in 2002 and is held every two years in Washington D.C. The goal is to build a house that is energy efficient, low cost, and of good design.  The most intriguing aspect of the effort is the idea that all these houses will produce as much energy as they consume, hence net zero homes.

Most of us spent considerably more zero? on our energy bills last year, over $6,000 for my household.  So how is net zero possible?  Basically, it is practically impossible to achieve it efficiently in most existing houses, though of course there are many ways to reduce energy consumption, but not to net zero.  New construction is a given.

The power company has been sending me comparison information lately that tells me my household is a bit lower in electricity usage than my neighbors, and I keep my oil burner tuned up.  Nevertheless, the two parents, two adult children and one adult dog who live there manage to consume over $6,000 on energy, which comes out to about $2.26 per foot for our 2,650 square foot house.

In the “Green” world, we all are all becoming more familiar with, there are certain fundamentals.  When it comes to housing, the first rule is to build a house no bigger than you really need.  The first step toward net zero is to recognize that the most efficient space is the space you do not build.   The size of new homes has been on the decline in recent years, so let’s pick 1,600 square feet as the size of our hypothetical not so big house (I am assuming the children do eventually move out and the dog stays).  Using my current energy cost of $2.26 per square foot, we get $3,616 in savings annually if the replacement house is a net zero house.

Using a 5% interest rate and a 30 year amortization, we have over $56,000 to invest in this house to achieve net zero.  Even with the high cost of photovoltaic panels (somewhere between $20,000 and $40,000 for our imaginary house depending on the availability of rebates and tax credits) and super-insulated building envelopes (double studded walls stuffed with ground up newspapers), this seems to be an adequate amount to cover costs.

Builders are indeed coming to market with net zero houses at competitive prices.  Most of the technology to accomplish this is not new, though it is continually improving, what is new is the trajectory of energy costs and the unlikely event that anything will happen to reverse that trend in the global economy we live in.

Expect to hear more about net zero homes.  Buildings represent 40% of all energy consumption in the US.  Making all buildings, including our homes more efficient will be an industry priority.