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The Cow Shed

Ground Source Heat Pump Case Study

The Cow Shed

A delightful new build property on the edge of the South Downs is a shining example of a building created with the future in mind. Moving from a draughty old Victorian property which was heated by a central oil fire system, the homeowners were keen to create a self build property which was utterly environmentally responsible and had sustainability at its heart. The Cowshed, which is home to Ruth and Mark Segal, was completed in 2016 and incorporates energy efficient elements into all aspects of the build to ensure it was sustainable. The four bedroom family home is of I-Frame timber construction and has 500mm thick walls clad in green oak shiplap. The way in which the walls are constructed has resulted in a staggeringly low U value, the walls are 0.111 W/m²K compared to the maximum allowed by the building regulations for new buildings of 0.3 W/m²K.

In addition, to the thermal insulation properties, heating and hot water is provided by a NIBE F1145 8kw ground source heat pump. Installed with its collector loops in two boreholes, the heating system delivers an ambient temperature using minimum power and is connected to an underfloor heating network. The electricity used to run this is largely offset by the 4kW of solar panels on the roof, which generate over 4000kWh per annum. Furthermore, A NIBE VPB 300 litre hp cylinder and a NIBE UKV 200 litre buffer tank ensure hot water is also generated for the property. High performace double glazing which has a 20mm argon filled gap completes the eco-friendly, energy efficient specification of the property.

The Solution

“This was a dream installation and one which showcases the truest elements of sustainability in new build homes,” commented Nev Galvin General Manager A Greener Alternative, the NIBE VIP Installer on the project. “It is very eco-friendly and energy efficient and, because we were involved at the architect stage of the building, we were able to ensure the building worked alongside the heating and plumbing to deliver a system that was tidy, concealed wherever possible and efficient. There is a lot of technology contained within the home and it all works together perfectly, creating a lovely family home which is comfortable, sustainable and easy to maintain.

“Two 100 m deep vertical boreholes were drilled each containing a single loop of 40 mm polythene pipe. The borehole was backfilled with bentonite clay which was thermally enhanced with graphite. These deep vertical pipes, the NIBE heat pump which is extremely efficient and a high specification underfloor heating system delivers 5kW of heating from every 1kw of energy used to power the system. In addition, a wood burning stove is contained within the home and the heat pump also heats the hot water for the home which is reinforced with a back up immersion heater.”


The property demonstrates the way in which heat pumps can work individually or form part of a wider vision for a sustainable home.

Renewable Heat Incentive (RHI) payments have been realised with a payment due of around £620 each quarter for seven years, lower than some due to the energy efficiencies delivered by the entire building.

Ambient temperatures are realised at all time, whatever the external weather conditions and several others who have visited the property as part of the Lewes Eco Open House weekend have been inspired by the ground source heat pump technology and the quality of the installation by A Greener Alternative.

The open house weekend allows those who have eco-friendly homes to showcase them to other people in the area, a popular residential location where mains gas is not available. It highlights how other types of energy can be successfully installed and used either in new build homes or as a retro fit project replacing antiquated systems that are dirty, expensive and from unsustainable fuel sources. Last year the Segal’s welcomed over 140 visitors over the weekend.


Mark Segal owner of The Cowshed commented; “We are utterly delighted with our new home and the ground source heat pump system which provides our heating and hot water. We were never fans of the oil fired system at our previous home and, when we began to design this self build project, we knew that we wanted to make it as sustainable and eco-friendly as practicably possible, future proofing it for generations of occupants to come.

"Whilst the ground source heat pump was a more expensive option for us we were emotionally committed to the environmental ethos of the property and, with the support and diligence of the team at A Greener Alternative, our dreams have been realised. I believe, that all new build homes should have a building regulation obligation to encorporate renewable energy systems wherever possible. It’s our responsibility to drive forward the availability of these technologically advanced and more sustainable ways of heating our homes and I am still amazed as to how it works so perfectly in keeping the family warm, no matter what the weather conditions.

“It is a complete pleasure to live here and we are delighted to showcase our home to encourage others and hopefully offer some practical advice on how to execute a successful installation of renewable heat and hot water systems. Clearly, I would highly recommend the technology from NIBE and A Greener Alternative for installations in the Sussex area.”

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