IS IT POSSIBLE TO SELF BUILD A

Sustainability expert Nigel Griffiths investigates how to build a house that generates little to no energy bills and technology to invest in to achieve this

Tesla’s (tesla.com) Powerwall 2 is a solar battery that can be floor or wall mounted, and is suitable for installation both indoors and out. Multiple batteries can be used in tandem to suit households with a high-power demand. It also features an internal inverter to simplify installation

If asked whether it’s possible to build a completely off-grid home, for the vast majority of self builders, the answer to the question will be no. Okay, perhaps that’s a bit harsh. There are some ways around the problem, depending on where you live and what sort of plot you own, but we’ll come back to this later in the article. It might instead be possible to build a home which has zero (or almost zero) energy bills – noting that this is a slightly different question.

Space heating & other power needs

Almost every new home is connected to the electricity grid; as most readers will know, gas is being discouraged for new homes. And that’s not in itself a problem, because electricity can be used for heating, as long as the dwelling doesn’t require too much heating in the first place (in other words, if it’s airtight and super insulated). The modest amount of power needed to heat a modern home can therefore be provided costeffectively by using some kind of heat pump.

Homes constructed to modern building standards already have a low demand for space heating, but to get anywhere near zero heating bills, you’ll need to construct something significantly in advance of current Building Regs and more like a Passivhaus home.