Project details
- Project name: Holbein Gardens
- Location: Belgravia, London
- Project type / Sector: Commercial
- GIA: 38,000 m2
Project team
- Client: Grosvenor
- Structural engineer: Heyne Tillett Steel
- Architect: Barr Gazetas
- Project manager: Capital & Provincial
- Cost consultant: Leslie Clarke
- MEP engineer: HDR – Hurley Palmer Flatt
- Main contractor: Blenheim House
- Steelwork fabricator: Eurban
- Steelwork supplier: Cleveland Steel and Tubes
Project description
Holbein Gardens is a retained and extended 1980s concrete-framed commercial building, refurbished with Barr Gazetas for Grosvenor, to deliver a modern sustainable workplace with increased floor area. The scheme adds a two-storey upward extension, with a roof terrace over an existing four-storey building and basement.
Sustainability and circularity drove the development, reusing most of the existing building fabric alongside low-carbon engineered timber extensions. The project pioneers the direct reuse of structural steel in London, incorporating 25 tonnes of reclaimed steel, and marks the first of several initiatives being developed and implemented across Grosvenor’s portfolio.
Reuse facts
9 tonnes of steel was sourced from Grosvenor projects across London, with a further 16 tonnes of reclaimed steel sourced through Cleveland Steel and Tubes (CST).
CST undertook all testing, following guidance set out in SCI P427.
The decision was taken very early in the project to use reclaimed steel as part of the low carbon design strategy.
The reclaimed steel was sourced from a donor site and stockist.
Success factors
Grosvenor, together with Heyne Tillett Steel and Barr Gazetas, championed the reuse of steelwork to meet their ambitious Sustainable Development Brief targeting net zero in construction and operation.
Circular principles were discussed early in the project which allowed the identification of a donor site within Grosvenor’s portfolio which was due to undergo demolition.
Challenges
The required floor to ceilings heights dictated shallow, heavy sections, which in this case precluded the use of reused steel.
The single-stage D&B procurement route made achieving cost certainty difficult as the main contractor lacked experience with reclaimed steel. Early engagement with CST (acting as stockist and fabricator) was beneficial.
Coordinating removal from the donor site into fabrication and then installation was complex and relied on contractors with direct contractual links to work together.