How energy efficient can you make an existing house, without spending the £150,000 typically needed to achieve Zero Carbon or passive House?
Very is the answer, if like at Clive Place you use all the grants available to reduce the heat loss and the draughts, put in a very efficient heating and distribution system, and install very good controls. At Clive Place all the energy used is renewable, either from the Solar PV panels on the roof or imported from a Good Energy, (who guarantee the renewable origin of every kW of electricity that they sell), and as a result you could argue that this is a zero carbon house.
It's won a Green Apple Award, and was awarded Superhome status in 2015. The thermal modelling predicted an annual energy cost, (for everything), of £500, which was accurate looking at the first years energy bills.
Whilst the grants last there's also payments back of about £250 from the Feed-in-tariff for the solar PV and over £1000 a year for the Air Source Heat Pump.