The design & build project, led by Passivhaus firm Green Building Store, will transform the barn into an all-purpose, flexible educational centre and space. A super-insulated timber frame structure will be built into the existing stone building, preserving the outward appearance of the barn, whilst offering EnerPHit* levels of performance. As well as working to high insulation and airtightness requirements, the project is developing some innovative solutions to supporting and working with the original stone barn structure, offering lessons for similar low energy retrofits in the UK.
In addition to the usual Passivhaus considerations of super insulation and airtightness, minimisation of thermal bridging and use of mechanical ventilation with heat recovery, the project will be tackling issues such as structural stability of the original barn structure, and prevention of water penetration from the stone walls and rising damp. In order to support and shore up the stone walls, the inner frame will brace the original barn fabric through a purpose-designed tie system, developed by the Green Building Store team and structural engineers. To minimize thermal bridging with this system, the tie connection to the inner timber structure has been carefully detailed to ensure it is fully insulated.
Clients Yorkshire Wildlife Trust have embraced the Passivhaus ‘fabric first’ approach of maximising the energy efficiency of the building fabric to reduce energy use to an absolute minimum. The EnerPHit ‘Cre8 barn’ will complement well what the Trust is trying to achieve at the Community Farm.
Rob Stoneman, Chief Executive at Yorkshire Wildlife Trust said:
“The greatest threat to wildlife across the globe is now undoubtedly a changing climate which is estimated to lead to the extinction of 90% of Earth’s biodiversity. This is why Yorkshire Wildlife Trust must play its part to avoid climate catastrophe as part of its work to conserve wildlife here in Yorkshire. The design of the EnerPHit Cre8 barn, will ensure that its heating requirements are tiny – a public example to show how good design can be used to retrofit low carbon living into old buildings; breathing new life into derelict buildings in more ways than one.”
The Cre8 barn is being built using funding from Veolia Environmental Trust and will be an education centre for the many volunteers and visitors to the farm. With a communal kitchen, demonstration area and meeting space planned the barn will accommodate both formal and informal education sessions, from school kids to trainees working towards accredited qualifications.
Green Building Store Director and Project Leader Bill Butcher will be writing regular blogs following the progress of the build and sharing detailing and lessons from the project at: www.greenbuildingstore.co.uk/enerphit
* EnerPHit is the Passivhaus Institut ‘s standard for retrofits and recognises the difficulty of achieving a full Passivhaus standard in existing buildings, by having slightly relaxed requirements for airtightness and space heating demand. The space heating requirement for EnerPHit is 25 kWh/m2/year (as opposed to 15 kWh/m2/year for Passivhaus) and airtitightness requirement is 1.0 (rather than 0.6 air changes/ hour).
Developed in Germany in the 1990s, Passivhaus is a quality assured standard and methodology for low energy building, which can help create buildings which use around 90% less energy than standard UK buildings. Passivhaus design is based on the principle that reducing heating loss to the minimum is the most cost-effective way of creating a low carbon building. Passivhaus is the leading international low energy, design standard, with over 37,000 units of houses, schools, offices and other buildings designed, built and tested to the standard across the world.
Green Building Store
Green Building Store has been at the forefront of introducing Passivhaus products and design into the UK. Its construction division Green Building Company built the pioneering Denby Dale Passivhaus, the UK’s first Passivhaus built using traditional British cavity wall construction. Green Building Store won a Queen’s Award for Enterprise: Sustainable Development 2009 for its “pioneering approach to sustainability” and for delivering “cutting edge sustainable products to the market”.
Tel: 01484 461705, www.greenbuildingstore.co.uk
Yorkshire Wildlife Trust
Yorkshire Wildlife Trust is a local charity working for a county rich in wildlife. The Trust looks after over 95 of Yorkshire’s best places for wildlife, and encourage people to visit and get involved with their care. The Trust stands up for Yorkshire’s wildlife wherever it is under threat, and work with others to find solutions that benefit both wildlife and people. They inspire thousands of children, families and others every year, reconnecting them with their local environment and wildlife. With the support of these people, the Trust is restoring and recreating a Living Landscape in Yorkshire and raising awareness of, and fighting for, Yorkshire’s Living Sea.