Brunel Building

Brunel Building, a 17-storey new-build workplace building, overlooks the Grand Union Canal and Paddington Station, the London terminus to Isambard Kingdom Brunel’s Great Western Railway, and is next to the site of Brunel’s first ever bridge. The elevated A40 expressway runs past and the Elizabeth Line, the new cross-London railway, stops near-by. One hundred-year-old cast-iron subway tunnels run beneath the site. This unique context sets the tone for the design of Brunel Building. The brief called for innovative workspace which would attract occupiers, as well as highlighting the significance and amenity of the area. The solution was technically driven by the presence of the canal and two underground tunnels running across one corner of the site. The steel diagrid exoskeleton is not only visually arresting but allows the building to span the tube lines. The building is pulled back at this corner to reduce loading, while a line of piles between the two tunnels helps to distribute foundation loads. Pushing the superstructure to the outside delivers column-free internal floor space, offering maximum flexibility and unimpeded views. The external structure also shades windows, allowing larger areas of glazing and deep daylight penetration. This impression of light and space is further enhanced by the high floor-to-ceiling dimensions. The floor structure and services are integrated into as tight a zone as possible to further increase ceiling heights. Building services have been left on display to reveal how the building has been constructed. This strategy is most emphatically revealed through the exposed external structure, while vibrant orange, inspired by waterside safety equipment, was chosen to highlight mechanical and structural elements and canal-side public lifts. Materials such as concrete, steel and sawn oak have been left exposed internally, and service ducts and pipes are visible. Environment and social sustainability were central to the ambitions of both design team and client. The external diagrid structure provides 20% shading to the facades, helping to reduce energy demand. An Aquifer Thermal Energy Store, with two forty-storey deep boreholes, provides low-carbon heating and cooling. Exposed undersides of the structural precast concrete floor panels help to deliver comfortable interior thermal gradients and more volume per person. Leaving the ceilings exposed also saved more than 540 tonnes of embodied carbon. More than 90% of construction waste was recycled and ground blast-furnace slag (a waste product from iron and steel production) was used in the concrete. The existing building on the site spanned this section of the canal blocking access and views along the canal. The canal-side walk is now publicly accessible for the first time in more than 200 years. Motorized hangar-sized glazed sliding doors can be rolled back to provide an extension to the new tree-lined towpath walkway. Passers-by can visit the canal-side restaurant café and bar and view the public art in the triple-height reception concourse. Meanwhile, occupiers have access to two expansive roof terraces with views across London. Soft landscaping, planters with wildflowers, trees and nesting boxes all contribute toward re-establishing the local ecology in what was previously a light-industrial area. All workspace was oversubscribed long before completion by a remarkably diverse ecology from many sectors; Sony Pictures, the Premier League, Alpha FX, Splunk, Hellman & Friedman, Coach and Paymentsense.