The UK Technology Strategy Board launched a competition to help increase the capacity of the UK construction industry to carry out domestic refurbishments aimed at reducing carbon emissions in 2009. The team led by Metropolitan Housing Partnership and Anne Thorne Architects Partnership, won funding to carry out such a refurbishment on 10 Hawthorn Road in North London, UK. The general approach taken by the team was to insulate the external envelope to Passivhaus standard; to reduce the infiltration rate to as near Passivhaus standard as possible, and to install suitable low carbon systems to provide heating and hot water with an aim to achieve an overall energy consumption reduction of 80% compared to an estimate for the original house. The chapter covers the different systems installed in the house; namely a combined gas-solar unit, for domestic hot water and back up space heating, and Mechanical ventilation with heat recovery system for providing sufficient warmed fresh air.