All-aboard Landolt & Brown’s public-spirited West Hampstead Thameslink station.
Landolt & Brown’s modest yet thoughtfully designed West Hampstead Thameslink station in London provides gating and ticketing facilities, staff and passenger support accommodation, as well as a small retail concession. The two-storey structure is approached
from West Hampstead’s main thoroughfare, West End Lane, along a new linear public space that provides direct views of the station from the town centre.
The key design generator is an avenue of protected lime trees that runs along the northern side of Iverson Road. Retention of the trees necessitated locating the station around 100 metres west of West End Lane, moving it back from the main street frontage and potentially obscuring it from the town centre.
In order to provide a generous walking route along this narrow side street and to make it clearly visible for passengers approaching on foot from the Jubilee Line and overground stations further south, the sloping railway embankment on the north side of Iverson Road was leveled to bring it in line with the existing pavement. A sheet piled retaining wall was then used to create a generous public space leading to the station.
On its primary public frontage, the retaining wall is lined with glazed bricks incorporating a distinctive saw-tooth profile. The undulating surface provides visual interest, while also discouraging graffiti, fly- posting and unauthorised signage. Inspired by the foliage of the protected trees, and to aid wayfinding and orientation, the colour of the bricks varies from dark green at West End Lane to lime green at the station entrance. Luminaires concealed within a projecting pressed steel parapet, illuminate the public space and provide subtle wall washing.
The measures taken to safeguard the lime trees include the use of root protection membranes, lightweight aggregates (as back-fill), and permeable reconstituted stone paving to ensure adequate root aeration and irrigation.
The new concourse canopy is folded to form the northern elevation of the building, extending down to overlap the railway retaining structures. Fenestration and construction detailing are kept to a minimum along this frontage to reduce maintenance above the railway and to reflect the functional, monochrome character of the embankment.
The glass and steel envelope is predominantly naturally ventilated; only the staff areas are climate controlled and independently insulated. An overhanging roof canopy used in conjunction with high-performance thermal glazing minimises heat gain and reduces heat loss.
The primary structural frame is steel, with a combination of I-section columns and castellated roof beams to facilitate high level services distribution. Junctions between the columns and roof beams are portalised to reduce wind-load deflection. The double-height structure sits on stepped, piled foundations which accommodate the steeply sloping geometry of the embankment. Pre-cast concrete planks form the primary structural slab.
The vertical envelope on the public facades is a steel-framed, double-glazed cladding system. Clear glazing encourages transparency and brightness in the public concourse, while the plant and operational support accommodation is concealed using an opaque, dark green interstitial coating applied to the glass. A band of fixed, powder-coated steel louvres located at the head of the wall provides passive ventilation and connects to a corresponding band of internal louvres at the perimeter of the internal suspended ceiling system.
Comprising a profiled steel- sheet cladding system, the envelope treatment is deliberately different on the railway facade. In architectural terms, this allows the roof to ‘fold over’ and become the north elevation, deliberately engaging the form of the building with the civil engineering structures which retain the railway embankment. The fenestration is reduced to one opening window (to allow for cross-ventilation in warm weather), which minimises maintenance on the railway side of the site.
The roof is a standing seam aluminium system on rigid insulation and aluminium lining trays, supported off steel joists. The chamfered perimeter comprises bespoke pressed-steel, powder-coated profiles which are angled to give a blade-like appearance to the canopy edge, and to create deliberate ‘folds’ at the corners where the roof meets the vertical cladding along the railway edge. The profile in turn becomes the retaining wall parapet. The underside of the canopy is clad with colour-coated aluminium panels.
Architect: Landolt + Brown; civil, structural engineer, m&e: Hyder Consulting; project manager: Network Rail Thameslink Programme; contractor: Carillion; client: Network Rail; photos: Peter Cook.
Selected suppliers and subcontractors
Glazed, engineering brick: Ibstock; curtain walling, windows: Schüco Jansen; external glazing: Pilkington; aluminium standing seam roof: Euroclad; steel wall cladding: Tata; suspended ceiling: Armstrong; Halcyon Ceramic internal wall tiling: Zenith Mosaic & Tiles; internal floor tiling: Waxman Ceramic Tiles; external reconstituted stone, permeable paving: Charcon Stonemaster; external lighting: Bega Lighting.
First published in AT225, February 2012