The Brunel Engine Shed
Posted on 17.12.2021
The structural timber extension to an historic railway building by Brunel in High Wycombe has now topped out.
When Studio Multi launched in September 2021 we posted a piece on the refurbishment of the historic Brunel Engine Shed in High Wycombe for Buckinghamshire Council. The focus was on preserving as far as possible the original timber roof structure and brick and flint walls. The original roof coverings had long since decayed and so a new slate roof, with insulation and waterproofing has been installed. Now the curtain walling is being installed to fill the shed with natural light and provide a connection with its surroundings.
The focus since mid-October has been the erection of the structural timber extension. The beauty of the original shed was the efficiency of the Brunel designed timber structure- the Queen post truss providing a wide span across the shed. The new timber structure uses modern technology to provide a clear span, using a Glulam timber portal frame and Cross-Laminated Timber (CLT) infill panels.
As the entire building envelope, the mezzanine and the rooms within are constructed in timber from the same supplier and sub-contractor, the speed of construction was very quick- 6 weeks in total. As there are no wet trades it has been a quick and clean process.
The portal frame is tapered; wider where there is a heavier load and slimmer where the load is lighter. This has resulted in an elegant form with some beautiful triangular junctions.
The new space is honey- coloured and bathed in natural light, even on a grey, December day. The use of timber in construction is celebrated for having low embodied energy and being renewable; it is also very beautiful with natural variances in grain and colour.
The CLT panels and Glulam beams are joined longitudinally with finger joints and the Glulam posts and rafters are connected with steel flitch plates and dowelled joints. Contrasting with the visible steel bolts and brackets (and now carbon fibre rods) in the original shed.
The mezzanine in the new extension provides a new vantage point to view the original building and provides additional space for the incoming tenant.
Next steps are the installation of the zinc cladding and installation of remaining windows.
The main contractor on this project is Quinn, with their sub-contractor Constructional Timber Manufacturers supplying and installing the Glulam and CLT cassettes that form the structure and envelope to the new extension. The beautiful timber structure was designed by Heyne Tillett Steel alongside Hawkins\Brown, where Nicola Rutt was project partner prior to starting Studio Multi, which is retained as client architect.