easi-joist® helps achieve 'outstanding' BREEAM accolade

Wolf Systems’ easi-joist metal-web joists have played a crucial role in the design of one of the UK’s most energy-efficient new buildings, the Shrewsbury centre of animal welfare charity Dogs Trust. The project is one of only six buildings in the UK ever to have received an “Outstanding” rating under the BREEAM (Building Research Establishment Environmental Assessment Method) energy rating method.

Dogs Trust is the largest dog welfare charity in the UK and its mission is to bring about the day when all dogs can enjoy a happy life, free from the threat of unnecessary destruction.

The single-storey building which houses the reception area, training barn, kitchen, offices, vet suite and re-homing kennels, incorporates a timber-frame and pitched tiled roof constructed using highly-insulated cassettes made from easi-joists supplied by a local Wolf Systems manufacturer.

“We needed to build 220mm of thermal insulation into the cassettes to achieve the optimum level of thermal resistance” says the building’s designer, Peter Napier of Shrewsbury practice Napier & Co. “The metal-web joists enabled us to produce a deep system with a continuous layer of insulation.”

The cassettes achieved a U-value of 0.14 – 0.15 W/sq m K and were designed for maximum air-tightness. The finished building has an air-tightness value of 2.5m3/m2/hr at 50Pa.

Energy-efficiency was a primary concern for the client, says Peter Napier. “Their previous buildings had all been conventional structures and their energy bills were massive” he says. “’Traditional’ meant putting heating and ventilation into a building and letting them fight it out.”

Press OutStanding BREEAM Accolade 1

After meeting Dr David Strong of sustainable building consultancy David Strong Consulting Ltd., Peter and his Dogs Trust client decided future centres had to be designed around a low-energy envelope.

“We had no previous knowledge of sustainable building techniques, so this was all new to us” says Peter. “All credit must go to the Dogs Trust for taking such a bold decision” he adds.

The Shrewsbury centre uses a combination of sustainable technologies besides the high performance timber frame envelope. These include a 30kW photovoltaic installation, a 56kW biomass boiler, a green roof over part of the building and a rainwater harvesting system.

The building was assessed by the BRE against its Environmental Assessment Method (BREEAM) and achieved an “Outstanding” rating – one of only six projects (and so far the only ‘bespoke’ project) ever to achieve this. With a score of 94.44%, the building can boast the highest level of credits ever awarded under BREEAM.

Peter hopes to repeat the success of this project with the next Dogs Trust centre, now nearing completion in Loughborough. He is also keen to improve the construction process through the use of Building Information Modelling (BIM).

The Shrewsbury Dogs Trust centre was designed using Autodesk’s Revit Architecture software – and Wolf’s Horizon software is the first timber frame design suite to be built on a Revit platform.

For further information please contact

Email: sales@wolfsystem.co.uk.
Tel: 02476 602303

Wolf Systems Ltd
Shilton Ind Est, Shilton,
Coventry CV7 9QL