Boundary House, City of London – Projects

The redevelopment of Boundary House will add a new social focus to the Fenchurch Street area, taking a constrained infill site and adding a mix of leisure, entertainment, cultural and educational spaces. The building will almost double in size, from 8 storeys to 15, and create 11,221sq m of floor space for a 311 key hotel for the Ploberger Hotel Group.

We explored multiple options with the project team to try and retain as much of the existing building as possible. The 1950’s reinforced concrete frame was in poor structural condition, with carbonation and reinforcement cover issues. Shallow floor to ceiling heights with only 2.2 metres headroom below the numerous downstand beams would have required significant column removal to create the hotel’s room layout and ensure the curvature of the façade aligned with the street.

Structural investigations showed that the existing core was inadequate for additional wind load and for increased vertical transport requirements, meaning that we needed to balance elements of reuse with creating a new core. The basement and ground structure have been retained and the new superstructure frame in steel has demountable metal deck composite floors to allow the frame to be deconstructed and optimised for reuse of materials. While the existing superstructure was no longer fit for reuse in situ, the aspiration is to apply circular economy principles as far as possible, including the use of second hand steel for parts of the frame, to reduce embodied carbon. The proposed greening strategy will also see 45 trees planted at roof level and includes green and blue roofs, targeting a BREEAM Excellent rating.

The hotel will have spaces that are open to the local community and public, created in consultation with local stakeholders, producers and education organisations. These include 456sq m of workspace focused on education, skills and training, free meeting rooms for students and free room hire for the wider community.