A curvilinear arts building in Slough by Bblur and CZWG is constructed from steel and aluminium

Buildings.

Photos
David Butler, Hufton & Crow

Slough Cultural Centre is a flagship community building forming part of the £450m Heart of Slough regeneration scheme. Designed by Bblur Architecture (shell and core) and CZWG Architects (interior) with engineer Peter Brett Associates, it is conceived as a covered street linking two new public squares. The three-storey structure is fully glazed at either end and features a concave northern elevation that is curved in two directions. The internal accommodation includes a library, gallery, multi-purpose performance space and classrooms.

Buildings.

Belying its complex fan-like shape, the building employs a regular 7.5-metre structural grid, with only the double-curved north facade constructed ‘off-grid’. ‘We chose to build in steel primarily for reasons of cost and speed’, says Bblur partner Matthew Bedward. ‘Steel also allowed us to achieve a sculptural form with relative ease and within a reasonable time-scale.’

The primary structural frame comprises 273mm-diameter CHS columns supporting 406x178mm universal steel beams, with 350x127mm joists at 2.5 metre centres. The north elevation, which follows the curving perimeter of St Ethelburt’s churchyard, adopts a ‘long arch’ solution to minimise the number of columns that can be seen through the ground-floor curtain wall. The aim is to strengthen the visual connection between inside and outside, while giving the structure an elegant lightweight appearance.

Buildings.

Taking the place of the ground-floor columns are a series of primary, curved steel I-sections, which are supported by a propped, single radius, 324mm-diameter CHS arch that spans almost the entire length of the facade. Closely spaced at alternating vertical centres of 1.1 metres and 2.2 metres, the 152x152mm facade steels form a rigid ladder frame that facilitates fixing of the external metal skin and double-glazed units with minimum need for secondary steelwork. The 3mm-thick polyester powder-coated aluminium cladding panels are curved only in the vertical plane. The horizontal curve is achieved through faceting, with the shallowness of the radius ensuring a smooth, unbroken appearance.

Buildings.

The project was procured using BIM, with Bblur coordinating the master 3D CAD model and assuming responsibility for setting out, (including the steel structure), and CZWG taking responsibility for services co-ordination with their interiors. The model was supplied to Caunton Engineering relatively early in the detail design process. Liaising with the architect and engineer, steelwork contractor Caunton developed its own fabrication-based model, which was subsequently fed back into the master model and used for clash detection. Bedward describes the process as ‘seamless’, resulting in a high degree of co-ordination between the steel structure, services and external skin.

Buildings.

The steel frame was erected in three sections, starting at the east end of the plan and working west. Resembling a ‘kit of parts’, the frame was bolted together using a crane and cherry picker over a period of four months. The 60-metre- long CHS arch comprises three separate sections, which were spliced together on site and temporarily propped while the curving vertical I-sections were bolted to flanges welded to the top face.

Download Drawings

Credits

Architect
Bblur Architecture
Interior
CZWG Architects
Structural engineer
Peter Brett Associates
Steelwork contractor
Caunton Engineering
Contractor
Morgan Sindall Construction