Creative solutions to retrofitting one of London’s modernist icons

by Younha Rhee, Technical Director

Designed by Richard Seifert and Partners in the 1960s, Space House was initially home to the Civil Aviation Authority and added a dash of space-age glamour to London’s Kingsway with its distinct cylindrical tower and a bold concrete façade.

Its iconic status was cemented in 2015 when it received a Grade II listing, but changing environmental standards and tenant demands meant that an ambitious retrofit was on the cards. Spearheaded by Seaforth Land with architecture practice Squire & Partners, Atelier Ten took on the challenge of bringing this unique architectural landmark into the modern era and turn it into a state-of-the-art workplace building.

Our sustainability strategy considered approaches relating to energy, transport, water, health and wellbeing, materials and ecology. This informed our decision to install all-electric energy systems, with active chilled beams, extensive cycling facilities, efficient water systems, openable windows, a biodiverse green roof and landscaped entrance areas.

It is a testament to the original architects and their preference for natural light and ventilation that the team could use the existing floorplates to accommodate contemporary workplaces. The ability to retrofit a building is tied to its flexibility, which is limited by its floor-to-ceiling height. At Space House, the internal dimensions were just about sufficient, but combined with limited riser spaces, still necessitated bespoke solutions as some of the usual high-performance systems simply wouldn’t fit.

Exposed ceilings feature an active chilled beam solution and track lighting. These solutions help to maximise the feeling of spaciousness inside – the former makes most of the building’s thermal mass while the latter allows flexibility for users. Openable windows allow for natural ventilation during shoulder seasons.

Façades also required a custom solution, as external insulation on a Grade-II listed building was not possible without altering its modernist character. The parking in the basement, designed in the car-centric 1960s, has been converted to 555 cycle spaces along with end-of-journey spaces – with the car ramp now serving cyclists for easy access. Air and water source heat pumps, located on the roof will provide the necessary heating and cooling, resulting in a 46% reduction in carbon emissions in the newly extended parts of the building, and a 70% reduction within the existing fabric.

By far the biggest challenge was the absence of accurate data. The building had undergone at least two upgrades since it was built, and the team had limited access to information about their exact nature and the overall fabric performance. This required an agile approach during the design and construction phases to ensure accuracy throughout.

When the building opens later this month, it will be one of the first listed commercial buildings to receive a BREEAM Outstanding certificate under the current BREEAM scheme. The integrated sustainability strategy also means Space House will receive NABERS and Fitwel certifications.

Space House Environmental Strategies

This building will prove that designing a net zero carbon building does not necessarily mean that you have to demolish and build anew. Honest, open and constructive lines of communication between the partners about the potential benefits and trade-offs helped us navigate the process and maintain the heritage value while optimising environmental performance.

Space House demonstrates the importance of making beautiful, user-friendly buildings. That is what drove Richard Seifert and Partners in the 1960s and ultimately allowed our team to extend their legacy into a new millennium. To truly make the built environment more sustainable, we must do all we can to make heritage assets tread more lightly on the planet and take inspiration from them by making sure that as much of what we build today can become a heritage asset of tomorrow.

Space House Interior. Photo: Squire & Partners

Explore more of Atelier Ten’s commercial projects here.