Brockholes Visitor Centre
Project Title: Brockholes Visitor Centre
Location: Preston, Lancashire
Building Owner: Lancashire Wildlife Trust
Architect: Adam Khan Architects
Builder / Main Contractor: Mansell/Balfour Beatty
Structural Engineers: Price & Myers
Joinery: B & K Structures
Wood Species: Austrian engineered timber, British timber oak shakes, Structural Insulated Panels (SIPs) made from Orientated Strand Board (OSB)
This RIBA competition winning project for a new visitor and education centre at Brockholes was awarded the new BREEAM Outstanding rating for sustainability at the interim stage, in large part because of the extensive use of timber throughout.
The project, on an area of national environmental importance at Brockholes Wetland and Woodland Nature Reserve in Preston, sits on a site made up of redundant gravel pits and ancient mixed woodland. The site is owned and is being developed by the Lancashire Wildlife Trust with funding from the Newlands Programme; an initiative of the North West Development Agency and the Forestry Commission.
This is a highly unusual project in that the entire centre is built on a large concrete pontoon on a lake within the reserve. This was the imaginative response by the architects to deal with the difficulty of building on an area prone to flooding. The pontoon was made by casting concrete around large polystyrene void formers, forming a solid yet buoyant raft foundation for the buildings. The pontoon is kept anchored in place by four piles embedded in the lakebed and accessed via articulating bridges, which allow it to rise in flood conditions: a model that could potentially be applied to many buildings constructed on flood plains.
The centre itself is made up of a cluster of large and smaller timber framed oak clad buildings housing various facilities – from bustling public areas including a café, conference facilities, and a shop, to quieter, more reflective areas for learning about and viewing the surrounding wildlife habitats.
The timber buildings are built from glulam portal frames under a timber Structural Insulated Panels (SIP) ‘skin’ that provides racking resistance to the buildings while ensuring a high level of insulation and air tightness. The splaying V-shaped glulam rafters are up to 10m long, joined with steel flitch plates due to their complex geometry and high connection forces. Sustainably sourced in Austria, they were precision engineered to reduce on-site time and eliminate wastage. The buildings are clad in oak shingles: rough tiles formed from tree stumps that would otherwise have been discarded. Internally, a recycled newspaper insulation was sprayed on to the underside of the SIPs, providing an excellent low-cost and sustainable acoustic dampening in public areas.
The project aimed for zero-carbon both in use and production, using materials of low embodied energy, high levels of thermal insulation and building airtightness, natural ventilation, and off-site prefabrication as well as on-site energy generation and waste treatment. The sourcing and durability of the materials used, potential for recycling, and the distance to site were all considered within the design.
The buildings really celebrate timber as an ancient and versatile building material that, through modern application and construction techniques, creates an inspiring and welcoming environment.
Value: £8.6m (£9m including landscaping and habitat creation)
Completed: May 2011
Opened: May 2011 by wildlife cameraman, author and presenter Simon King
Funding: North West Regional Development Agency.
Quote: ‘it is rare that the stuff of a building, as well as its relationship to nature, gives so much pleasure.’ Rowan Moore, The Guardian