This small new build cottage has been constructed to a high standard of energy efficiency. The space heating and a proportion of its hot water requirements are supplied by a ground source heat pump (GSHP) located in an external plant room that adjoins the house.

We installed a Kensa 6kW compact heat pump with a 210 litre unvented DHW storage cylinder. The ground collector consists of two 50m slinkies in a vertical trench connecting to a 2-way manifold in the plant room. Heat is distributed by underfloor heating throughout the ground floor, supplemented by a duct heater that pre-heats the supply air from an MVHR system.

A ground-mounted 4.0 kWp PV array has been located about 70 meters from the house. It is shielded from view by a purpose-built earth bund. It helps to offset the electricity consumed by the heat pump, both by generating power at times when the heat pump is operating and financially through Feed-in-Tariff payments.

During late spring, summer and early autumn the majority of the hot water requirement will be met by an Immersun PV switch which diverts surplus PV to twin immersion elements in the hot water cylinder, firstly to the top of the cylinder, and subsequently to the lower part of the cylinder.