Legendre picked for Mayfair project: low‑carbon office design notes for engineers
Reviewed by Joe Ashwell
First reported on The Construction Index
30 Second Briefing
Legendre UK has been appointed main contractor for Berkeley Estate Asset Management’s 135,000 sq ft redevelopment of 50 Stratton Street in Mayfair, designed by Stiff + Trevillion as an all-electric office building. The scheme targets BREEAM Outstanding and LEED Gold, with a stated zero embodied carbon approach using lightweight steel and four new cross-laminated timber floors. Works include new stone-clad façades with aluminium-framed windows and curtain walling, with construction due to start in June 2026 and complete by mid-2028.
Technical Brief
- New stone-clad façades will integrate aluminium-framed windows and curtain walling, affecting thermal and acoustic performance.
- Cross-laminated timber floors over lightweight steel demand careful vibration, fire and differential movement design checks.
- Curtain wall and stone interfaces require robust fixings into existing or new primary frame, with strict movement-joint detailing.
- Targeting both BREEAM and LEED will necessitate dual-compliant material sourcing, commissioning, and building performance verification regimes.
Our Take
Legendre UK’s role at 50 Stratton Street follows its involvement in the Grove House retrofit in Hammersmith (approved April 2026), signalling a deliberate push into complex London refurbishment and repositioning projects rather than new-build alone.
With construction at the Mayfair site not starting until June 2026 and running to mid-2028, Legendre UK is effectively locking in a medium-term London workload, which can help smooth resource planning and subcontractor relationships across multiple central London schemes.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
