Millfields Cottage, Rowhook, West Sussex. A house with the top ranking in the government’s energy-efficiency ratings. It has air-source heat pumps, solar panels and a mechanical ventilation with heat recovery system. The garage has a charging point for electric cars. 4 beds, 3 baths, 2 receps, 10 acres. £3.25m Strutt & Parker 01483-306565.
Bayham Hall, Lamberhurst, Tunbridge Wells, Kent. The west wing of a restored, 1870s, Grade II-listed mansion, situated in an Area of Outstanding Natural Beauty. It has a geo-thermal ground source heat pump, solar panels and a thermal insulation system. 8 beds, 4 baths, 2 receps, gardens, 5.35 acres. £3.95m Hamptons 01892-640316.
Villa de Palmas, Double Bay, Eleuthera, Bahamas. An ocean-front estate powered by a solar farm and underground water system. There are three two-bedroom, air-conditioned houses with…