Grade Two Listed Theatre

Domestic Install Building
Domestic New Build
26th October 2016

Grade Two Listed Theatre

The Mill at Sonning


  • To replace a thirty year old gas boiler and radiator system with a modern, renewable energy solution
  • To reduce the properties running costs and obtain the commercial RHI


Installation of a 120KW Viessmann ground source heat pump (GSHP) system, replacing the thirty year old gas boilers, along with a new 50+ radiator system installed over four floors. The GSHP system is powered by a micro hydro system, producing electricity from the River Thames situated below the property.

The ground source heat pump system takes energy from an open loop borehole system, which abstracts water from the underground aquifer. The water is passed through a heat exchanger where heat is taken and used by the heat pump. The cooled water is then returned back into the River Thames.

Hot water is produced by extracting warm air from the commercial kitchens. This is then run through an inbuilt air source heat pump that is sited above a large hot water cylinder, which converts the warm air into hot water. The cooler air is then pumped back into a different part of the kitchen, making it a far more favourable place to work.

The property also has its own water supply. Therefore, heating, hot water, electricity and water are all produced from natural renewable sources, making this grade two listed building fully sustainable.

The team were nominated for Commercial System of the Year (2015) for this project.

The Details

  • Project Type: Commercial (retro fit)
  • Technology: Ground Source Heat Pump
  • Location: Berkshire
  • System Size: 120KW
  • Additional Works: New 50+ radiator heating system over 4 floors. Dedicated hot water system for commercial kitchens.
  • Cost of Installation: £102,000
  • Bill Saving (P/A): £12,000
  • Income (P/A): £15,000
  • Payback: 3.7 Years
  • ROI: 26%