Space House – Masterclass in Sustainable Heritage Retrofit
Squire & Partners has sensitively retrofitted and extended the iconic Grade II-listed Space House for Seaforth Land, creating 255,000 sq ft of high-performance workspace and retail. Originally designed by George Marsh and Richard Seifert in 1968, this brutalist landmark is now one of the UK’s largest BREEAM ‘Outstanding’ listed buildings, sitting six years ahead of the RIBA 2030 Climate Challenge targets.
The Architectural Vision
The project sought to reinstate Seifert’s original design intent by “unstitching” previous interventions. By retaining 90% of the original structure, the project saved an estimated 10,000 tonnes of carbon.
The distinctive cylindrical Tower and rectilinear Block were vertically extended using a hybrid in-situ concrete method. This involved a painstaking process of removing the original precast T-form structures, renovating them, and reinstating them atop new cruciform units carefully matched to the 1960s concrete composition.
Bespoke Craftsmanship by MASS Concrete
Inside, the material palette honours the building’s mid-century concrete soul. MASS Concrete worked in close collaboration with Squire & Partners through an extensive sampling process to ensure the internal elements met rigorous sustainability and aesthetic standards.
Our contributions across both the Tower and Kingsway (Block) buildings include:
- Feature Wall Panelling: Custom fluted and polished concrete panels across the Ground and Mezzanine reception spaces.
- Reception Desks: Bespoke cast furniture that serves as the focal point for the main entrances.
- Planters: Integrated concrete greenery solutions that bridge the gap between the internal architecture and the revitalized public realm.
Sustainability & Performance
- BREEAM Outstanding: The largest Grade II listed building in the UK to achieve this rating.
- Net Zero in Operation: A fully electric building utilizing air source heat pumps and
- smart cooling via operable windows.
- Certifications: Targeted NABERS 4.5 Stars, Fitwel 2-Star, and WiredScore Platinum.
Project Team:
- Client: Seaforth Land, QuadReal
- Architect: Squire & Partners
- Principal Contractor: BAM
- Bespoke Concrete: MASS Concrete
Photo Credits:
Gareth Gardner
Recognition & Awards
- 2026 Regional Finalist – Civic Trust Awards
- 2026 Creative Retrofit (Shortlisted) – The Pineapples
- 2025 Sustainable Renovation of the Year (Winner) – Dezeen
- 2025 Inside Out (Winner) – Mix Interiors Awards
- 2025 Workplace Interiors (Winner) – Mix Interiors Awards
- 2025 Major Projects (Winner) – Camden Design Awards
- 2024 Commercial Buildings (Bronze Award) – WAN Awards
- 2022 Future Projects: Commercial (Bronze Award) – WAN Awards
- 2022 Future Projects: Office (Shortlisted) – WAF Awards
- 2022 Retrofit (Shortlisted) – NLA Awards