National Trust Hardwick Hall: Biomass district heating scheme

re:heat were pleased to be appointed as main contractor to deliver the biomass heating project to the stunning and historic Hardwick Hall located in Derbyshire.  This was our sixth project with the National Trust, and we are delighted to be such an integral part of delivering their Renewables Programme, supporting their drive towards producing 50% of their energy from renewables by 2020.

In addition to the extensive grounds and gardens, Hardwick Hall is home to a variety of properties including an architecturally significant Grade I listed 16th century Mansion and a range of Elizabethan era properties which are now used as holiday homes, a restaurant, shops, offices and staff accommodation.

At a site with such historic and cultural significance, changing to wood fired heating and removing all heating oil from the site was a particularly important move, as it eliminates the risk of leaks and any problems that could be caused by an oil spill, thereby protecting the site from any environmental damage.

Hardwick Hall already had experience of renewable heating, as a 240kW pellet boiler was already providing heating to the restaurant, but the National Trust saw the opportunity to replace this boiler and significantly extend the district heating scheme to incorporate other properties, thereby removing fossil fuels entirely from the site.

Following a lengthy tendering process, and several rounds of redesigning and re-engineering the project, re:heat were awarded the contract to install the new biomass boilers and extend the district heating scheme to heat every building on the site, even the commercial greenhouse where plants are grown for the grounds and gardens.  By the time we’d completed the redesign, only the buffer tank and a short length of heat main remained of the original installation, with the previous boiler carefully dismantled and packaged up for redeployment elsewhere on the National Trust estate.


The two new ETA Hack 205 wood pellet boilers were installed into the newly renovated plant room, along with a large fuel store.  To connect the properties to the new biomass system, over 600m of Rehau Rauthermex underground heat mains was installed, providing a highly efficient method of distributing the hot water around the site.  Such a large network required a groundbreaking design and an excellent control strategy, and this project is – we believe – the first in the country to feature fibre optic connections to ensure precise control over all system components.District Heating Control Box Featuring Fibre Optics