In startling enviro-technology news, it has been reported that an ordinary 1950s house in California has been given a "green renovation" which has apparently made it a "Zero Energy House" and won its builders an award from the state government.

Not some nasty cold, dark hut for unwashed primitives, oh no

This is pretty interesting stuff, as the US Department of Energy says (pdf) that a "Zero Energy" building is one "with greatly reduced energy needs through efficiency gains such that the balance of energy needs can be supplied with renewable technologies".

In other words the Californian prototype house can supply all the energy it needs over time through its own renewable microgeneration equipment - if it uses external electricity supplies such as grid power at times, it compensates for this by providing surplus juice of its own back to the grid at others.

This sort of thing has always been possible, of course, but it generally means a dwelling without heating, hot water, cooking or air conditioning (the latter often seen as essential to life in much of California) and not a lot in the way of electrical appliances either.

But the Zero Energy ("Zenergy") House Prototype, created by Residential Energy Assessment Services ("Making Los Angeles Green") is no such primitive icebox/hothouse, suitable only for unwashed people in smelly clothes who eat their food raw and go to bed when it gets dark. It has heating, air conditioning, hot water, cooking, plenty of lights and appliances. Yet it is still "Zero Energy".

Eco-design news hub Inhabitat ("Green design will save the world"!) reported on the Zenergy House Protoype's opening this week in gushing terms:

The Zenergy House is a 1950’s [sic] remodel that delivers high on sustainability and low on energy use — net zero to be exact — thanks to the use of super-efficient green building strategies and solar panels on the roof ... The home is tricked out from head to toe with sustainable features and products, including a lot of the furnishings and accessories.

REAS themselves describe the remodelling process under the heading "Goal - Net Zero Energy".

But how did the technical wizards of REAS manage to deliver net zero energy with heating, aircon and all the trimmings in a 1950s house with nothing more than a few solar panels to power it?

We couldn't imagine how, so we asked them and company vice-president Ron Schwolsky promptly and courteously answered our questions. Unfortunately, the short answer as to how on Earth they made a house comfortable while using no energy from outside is that they didn't.