A symbol of the 1960s commercial property boom, Space House is a rare Grade II-listed brutalist building designed by Richard Seifert and Partners. Completed in 1968, it is recognisable by its cylindrical tower, precast cruciform facade supported on Y-shaped columns, rectilinear block, and connecting bridge.
A brutalist icon reimagined
The building was refurbished in 1996 and 2003 and occupied exclusively by the Civil Aviation Authority until 2019, when it was acquired by developers Seaforth Land and QuadReal Property Group. Squire & Partners’ retrofit removed layers of subsequent intervention to reveal the original architecture, while introducing rooftop extensions, 255,000 square feet of workspace, ground-floor retail spaces, and an improved public realm. The strongly articulated facade has been restored in a manner that preserves the building’s brutalist character while adapting it for contemporary use.
Restoring and extending the concrete structure
Around 90 percent of the original structure has been restored and retained, saving an estimated 10,000 tonnes of carbon emissions. An early example of hybrid in-situ and concrete construction, Seifert’s design employed precast cruciform concrete blocks arranged in a grid, enabling rapid and relatively low-cost assembly. This system also allowed additional floors to be introduced with limited impact on the overall appearance of the facade through the insertion of a new layer of replica cruciform units.
Two additional office floors have been added to the Tower, with a further storey added to the Block. The Block’s new eighth floor accommodates meeting rooms and a Club House comprising a bar and a 5,000-square-foot terrace accessible to all tenants.
The rooftop extension to the Tower reinstates Seifert’s intended clean roofline while increasing the lettable office area by 12 percent and providing a 3,600-square-foot roof terrace. It also conceals a new and efficient building services installation incorporating air-source heat pumps, replacing the air-conditioning units previously accumulated at roof level.
To construct the extension, the original T-shaped units forming the building’s crown were carefully removed, cleaned, and repaired. A new section was then formed using forty-eight replica cruciform units, whose concrete composition was closely matched to that of the original 1960s elements, before the restored T-shaped structures were reinstated above.
Reworking car-centred infrastructure
Designed during the rise of private car use, Space House originally incorporated extensive vehicle infrastructure. One of its three basement ramps has now been retained as dedicated cycle access, while the former underground car park accommodates storage for 600 bicycles, alongside showers, lockers, drying rooms, and changing facilities.
Elsewhere, an opening created through the two-storey basement provides 16,500 square feet of flexible, double-height event space. The former petrol station canopy at the base of the Tower has been enclosed to create the Filling Station restaurant, bringing activity to street level.
Connected workspaces and shared amenities
The Tower is entered through a spacious double-height lobby and reception area. Its 10,000-square-foot circular, column-free floorplates receive high levels of natural light, with the upper ten floors providing unobstructed 360-degree views across the city. Workspaces feature long sightlines, offering high levels of visual connectivity and supporting collaborative working.
Designed with a loft-like character, the offices feature polished concrete floors. New terrazzo flooring has been installed throughout the common areas, while original mosaic tiling has been retained within the stair cores.
Within the Block, a more intimate lobby leads to eight levels of workspace, each measuring approximately 8,000 square feet. The sky bridge connects workspaces across the first and second floors and supports a garden terrace at third-floor level.
Improving environmental performance
Space House is the largest Grade II-listed building in the UK to achieve BREEAM Outstanding. As external insulation would have altered the historic character of the facade, the environmental strategy instead prioritised high-performance glazing and operable windows as part of the building’s cooling approach. The deep articulation of the existing facade also provides passive shading, reducing direct solar exposure.
Heating and cooling are provided by bespoke chilled beams integrated within the existing radial ceiling coffers. Daylight sensors reduce energy use for artificial lighting, while low-flow fixtures limit potable water consumption.
The refurbished building achieved NABERS UK 4.5 Stars, supported by the integration of key architectural, MEP, and lighting solutions. The design also incorporates an upgraded digital infrastructure, achieving a Fitwel 2-Star rating and WiredScore Platinum certification.
