Hardman Square Pavilion, Spinningfields, Manchester

Introduction

Hardman Square Pavilion stands at the heart of Spinningfields, Manchester’s busy commercial district, yet this new building is utterly unlike the surrounding metallic and glass towers; the structure is timber, an exposed glulam frame which is clad with timber weatherboards overlaid with planting. This use of natural materials is enhanced and complemented by its setting in Hardman Square, a large public space which has been newly landscaped. Trees, plants and wildflower verges have created a ‘green oasis’ lined with paths and seats where office workers can pause to enjoy their verdant surroundings.

‘We were after a building that was different from the rest of Spinningfields and acted as a natural counterpoint to the glass and metal used on the adjacent blocks’, explains Neal Allen-Burt, partner at Sheppard Robson Architects. ‘The structure’s green skin underlines both physical and visual connections between the landscape and the building. Greened façades, including that of the roof, link views from both the low and elevated positions. Both those using the building or the public space are intrinsically connected and not mutually excluded.’

The Pavilion – four-storeys with a roof terrace – provides a permanent venue for The Ivy, a high-end restaurant and bar. The ground floor is a bar and brasserie, the first floor a private dining room, the second floor an Asian restaurant, and the roof is used for entertainment and events.

The design both echoes and contrasts with adjacent offices. Like the commercial buildings alongside, the structural frame is expressed on the façades as a dominant grid, but in this case the grid is of glulam timber and large diagonal steel bracing members. Within this grid the façade is a complex combination of glazing and horizontal larch weatherboarding, superimposed with planters of cascading greenery, designed as a ‘veil that wraps over and softens the urban form’. The use of timber creates a façade of warmth and variety in a business district dominated by a more sombre selection of façade materials.

In plan the building is an elongated rectangle with part of the long east elevation extending at ground floor level in the form of a glazed bay from which diners can look out over the square. On the gable ends of the building, the upper floors cantilever over the ground floor and on the north side this acts as a generous shelter for the main entrance to the restaurant. The cantilevered floors above are articulated at each level by the diagonal bracing.

The structure

The primary element of this four-storey structure is an innovative larch and spruce glulam frame on a regular six metre grid. The frame is exposed externally on all elevations so that the structural concept is clearly demonstrated, with visual connections to the locations of floor plates and columns. The exposed glulam members are of larch and concealed members are of spruce.

Diagonal steel bracing, fixed to the glulam frame and exposed in the same plane, helps to give rigidity to the overall structure, limits defection and has made it possible to create six metre cantilevers to the structural bays at the gable ends of the building. The complex junctions between steel bracing and glulam timber are exposed to highlight the importance of the connection.

Vertical steel bracing at the corners of the east and west elevations provides stability in the transverse direction while a series of cross-laminated timber (CLT) walls and cores provide lengthwise stability.

The upper floors and roof had to have a clear span of six metres yet match the relatively slim depth of the perimeter glulam beams. To achieve this, a system of pre-fabricated CLT and glulam rib deck floor panels has been used. The floors act as diaphragms which transfer lateral loads from the façade to the steel bracing and the CLT cores. The CLT and glulam rib deck floor panels provide generous and uncluttered floor-to-ceiling heights and when they are exposed the warm natural timber surfaces are revealed. The glulam frame and the CLT walls, cores and floor decks were manufactured by Stora Enso and designed, supplied and installed by B&K Structures.

The façade

The larch glulam frame members, at 480 x 280mm and 760 x 280mm in size, are clearly visible as the dominant element of the façade. They are also large enough to allow the walls to be set back 550mm within the structural depth of the frame, protecting them from excessive weathering.

The walls of the east and west elevations consist of solid CLT panels with prefabricated openings for double-glazed units. The CLT panels are clad with an insulated rainscreen of horizontal larch weatherboards. Timber was the clear choice for the cladding, harmonising with the glulam frame and with the landscape concept of the square. The larch weatherboards have been charred and heavily brushed to expose the grain. The charring controls the appearance and will contrast with the larch glulam members which, it is anticipated, will gradually silver with age.

The north and south gable walls and the ground floor extension to the brasserie and bar on the west elevation are all fully glazed.

The foremost element of the façade is a slender grid of dark powder coated steel set in front of the glulam frame and rising above the roof elevation. It is designed to reduce the scale and mass of the building to a more human scale. The grid supports a series of planters at the top and bottom of each structural bay, together with plant support struts and occasional panels of horizontal larch slats. The slats were charred and brushed to match the rainscreen cladding panels and are housed within prefabricated modules fixed in line with the front face of the steel grid. Their purpose is to provide shading and privacy to the building where required.

Sustainability

Timber is a renewable construction material and the timber manufacturer Stora Enso has calculated that the length of time required to grow the same wood again in the Austrian forest is 0.044 hours.

Stora Enso also calculated that a total of 289.64m3 of CLT and 172.42m3 of glulam was used for the rib-panels and frame of the building, which equates to 338 tonnes of CO2 being removed from the earth’s atmosphere.

The use of prefabricated timber components such as glulam and CLT for construction has other sustainable advantages. With prefabrication, material waste is minimised, construction time reduced and, as the building is lighter, less concrete is needed for foundations.

Awards

RIBA Regional Awards North West 2020 Shortlist
Wood Awards 2019 Commercial & Leisure Shortlist

Completion Date:

January 2018

Building Type:

Restaurant and bar

Location:

Hardman Square, Spinningfields, Manchester

Architect:

Sheppard Robson Architects

Structural Engineer:

engenuiti

Main Contractor:

BAM Construction

Timber Supplier:

B&K Structures

CLT and glulam rib panel manufacturer

Stora Enso

Timber Elements:

structural frame, walls, floors, cores, external wall cladding

Timber Species:

PEFC-accredited Austrian spruce and larch

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