55 Great Suffolk Street
Project summary: Retrofit of a historic Grade 2 Listed warehouse building in Southwark, London
Location: Southwark, London
Project type: Commercial
Size: 1412 sq m
Completion: Expected in 2024
Hawkins Brown (architect)
Symmetrys (structural engineer)
AKT II (engineering consultant)
Exigere (cost consultant)
CBRE (sustainability consultant)
Opera (Project Manager – 55 Great Suffolk Street)
Gardiner & Theobald (Project Manager – reclaimed steel initiative)
Sir Robert McAlpine (main contractor on 1 Broadgate)
Cantillon (demolition contractor on 1 Broadgate)
Cleveland Steel and Tubes (reclaimed steel stockholder and supplier)
- 55 Great Suffolk Street is a 15,000 sq ft historic Grade II Listed warehouse in Southwark distinguished by its Victorian architecture. This project seeks to create a highly-sustainable modern workspace, while minimising embodied carbon and preserving the building’s unique heritage.
- Committed to sustainability, Fabrix purchased reclaimed steel from demolition contractor Cantillon, from a site being demolished in the City (1 Broadgate) for reuse across two projects: Roots in the Sky and 55 Great Suffolk Street. As a UK first for a developer, the exercise is intended to serve as a proof of concept for steel reuse in real estate projects.
- Reused steel will make up the structure for a new external core. The building has 20.98 tonnes of steelwork overall, of which 97% (20.35 tonnes) will be reused. Around 43% of reclaimed steel (8.3 tonnes) was procured from the demolished site, and the remaining 57% of steel (11.1 tonnes) was procured from stockholder Cleveland Steel and Tubes.
- The upfront embodied carbon of the building (modules A1-A5) was estimated to be 386kgCO2e/m2 owing to steel reuse, representing a 36% reduction compared to the LETI 2020 design target of 600kgCO2e/m2.
Key drivers for steel reuse
Clients were driving steel reuse in this project as a low carbon solution.
Reclaimed steel procurement route: Around 43% of reclaimed steel was procured from a demolition contractor, and 57% of steel was procured from Cleveland Steel and Tubes.
Information available on reclaimed steel: The demolished (donor) building was erected post-1970s. The plans of the building were available, and grades of steel were known. In some cases, there were original certificates for materials.
Quality of reclaimed steel, testing and certification: The quality of the reclaimed steel varied from clean good quality steel to painted steel with shear studs that had to be removed. Cleveland Steel and Tubes coordinated testing via testing centres. CE marking for the reclaimed sections was achieved through conformance with EN 1090.
Warranty issues: No issues with warranties as the steel was CE/UKCA marked.
Cost of reclaimed steel versus new steel: The cost of reclaimed steel was lower than that of virgin steel.
Economical implications of steel reuse: The steel costs were marginally cheaper than new but there are associated costs with reprocessing and aesthetics. The project did not result in economic savings despite the impact of the Russia-Ukraine war on supply chains and steel availability, partly because it was the first time such a project had been undertaken.
Implication of steel reuse on project timelines: No implications on the project timeline. The reused material was sourced in advance of production requirements and was available when required.
Photo credits: Fabrix
Lessons learned, challenges and critical success factors
- Fabrix entered into an agreement with demolition contractor Cantillon, who were demolishing the British Land-owned 1 Broadgate in the City and had initially intended to recycle it. Concrete casings were removed and steel sections were hot-cut at each end.
- Stockholder Cleveland Steel and Tubes was engaged in the project to provide a solution for the storage, restoration, and recertification of steel. Steel sections underwent initial processing, with attachments removed and holes filled, and then tested and CE marked. Additionally, 11.1 tonnes of steel were procured from Cleveland Steel and Tubes to be reused in the project.
- The design of the building with steel reuse was relatively straightforward. The early procurement of steel by the client allowed the design to be based on the available steel sizes and sections. While the design process went smoothly, a few minor design iterations were necessary. For instance, certain beams were found to be deeper than anticipated, requiring additional coordination with the architect and resulting in changes to the layout. The depth of some steel sections caused issues with putting services through. Despite these challenges, the design team was able to navigate the reuse of steel without significant problems.
- Early engagement is critical. The designers engaged with steel reuse across RIBA stages 2 and 3 in this project. Ideally, this should be done earlier, at stage 0 or 1, when formulating the brief.
- Strong client support helped to drive steel reuse in this project. This is one of the first projects in the UK of its kind to reuse structural steelwork recovered directly from a demolition site. As the project progressed, processes had to be reinvented, and the success of the project was contingent upon the team’s positive attitude towards the challenge.
- Reusing steel requires the demolition of existing buildings, which in some cases is not warranted, and those buildings could be retrofitted instead. Steel for reuse should be targeted only when demolition is really required, and it should be reused as locally as possible to minimise emissions from transportation. The timing of demolition of existing developments needs to align with the construction of new buildings. Currently, there is no central register for this process, which makes the market for reused steel very illiquid.
This case study was compiled based on interviews with Cleveland Steel and Tubes, Symmetrys, and Fabrix, and published data, as part of the DISRUPT project (Delivering Innovative Steel ReUse ProjecT).