Rees Farm

Rees Farm - Eco House

Ground source review: Rees Farm

Owen built the high tech, eco house of his dreams in rural Gloucester, complete with Kensa’s market-leading ground source heat pump technology seamlessly linked to innovative smart controls.

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Ground source review: Rees Farm.

Owen Stinchcombe had been in property development for a number of years, so was used to purchasing and renovating houses. He searched for a suitable plot for five years, and eventually found a site in rural Gloucester where he could build the ‘Grand Designs’-esque home of his dreams. Owen built his eco-house, complete with a 15kW Kensa Evo ground source heat pump which is seamlessly linked to innovative smart controls to keep his home at an optimum temperature at all times. The system is integrated with a 6kW Solar PV array on the roof linked to battery storage, which generates and stores supplementary electricity which Owen can use to run the ground source heat pump.

It was important to Owen that the house was as environmentally-friendly as possible. He said:

We designed the build as close to Passiv-Haus standards as possible to provide maximum energy efficiency. This is my ‘forever home’, and I wanted it to be comfortable and cost-effective to run in the future. I’m practically self-sufficient in terms of power and heat – all good quality self builds are going this way.

There was gas in the area, but not directly to the property and it would have cost Owen thousands to get the infrastructure in place. When he compared the efficiency of gas to a ground source heat pump, the latter returning 300% versus 90%, he knew this was a better route to go down. Owen had researched renewable heating options and met Kensa at a self build show. He said:

I liked Kensa because they were helpful and informative, and knew what they were talking about. I changed my mind several times about what I wanted from the heating system and Kensa were always accommodating – nothing was an issue.

As he decided early on in the project that he would use ground source technology, he designed a plantroom in the basement specifically to house the heat pump unit.

There was a field on site which was perfect for slinkies. Owen wanted to be hands on with the build and decided to do the groundworks himself to save on labour costs. Kensa recommended an installer for the internals who worked with him on the project. Owen took advantage of Kensa’s MCS Umbrella scheme, which meant that the sizing and design of the heat loss and ground array were done by Kensa’s technical team to ensure that the project is fully eligible for funding from the Renewable Heat Incentive (RHI). He said:

Getting seven years’ of quarterly payments from the Government for the renewable heat definitely swayed my decision to go ahead with the system.

Owen was keen to have simple and seamless heating controls but with maximum control. The ground source heat pump is integrated with a whole house management system, which is also controllable by an app. By leveraging best of breed systems to monitor: temperature, occupancy, MVHR, energy and weather conditions, the set up maximises comfort whist keeping energy use and cost to a minimum. It runs autonomously, learning trends and providing data to assist future projects.

Not only the heating runs on this system, but every light in the house and garden is centrally controllable utilising occupancy sensors in every room and ambient light to adjust the brightness of each space. Having the whole house on one system allows for things such as hot water return loops to be run on actual room usage, rather than timers, further saving energy.

The plot had a little Cotswold stone cottage on site which Owen built directly on top of with a cleverly designed cantilever, which allows the second floor to overhang the original dwelling without any external support; this means from a certain angle the new build appears to be floating. A grass sedum roof adds an additional layer of insulation.

Although glass has been used frequently throughout the build, Owen compensated by installing high levels of insulation, and the original stone walls of the cottage heat up and retain warmth very well. Underfloor heating was specified throughout the property which works very well with the ground source heat pump to provide a constant and comfortable low-grade heat throughout the house.

Owen is very happy with the ground source heat pump. He said:

Although I can see how ground source heat pump technology might seem complicated to some people that really couldn’t be further from the truth. It works exceptionally well and it really is a simple and effective technology. I’m very pleased with how easy it is to maintain a comfortable temperature in my new home.

I would certainly advise people to speak with Kensa, as they gave me the right support I needed for my project and even recommended an installer who knows how the technology works.

Key Facts

  • 400m2 new build property
  • 15kW Kensa Evo ground source heat pump
  • 4 x 50m slinkies under field
  • Integrated with Solar PV & battery storage
  • MCS Umbrella service
  • Uses innovative smart controls