One Exchange Square

Retrofit beats demolition on the embodied carbon math, and One Exchange Square is the highest-profile London office project staking its commercial case on that argument. The 13-story scheme at Broadgate retains 90% of the existing 1990s structure, adds 430,000 square feet of premium Class A workspace plus 17,000 sf of retail, and is targeting BREEAM Outstanding, NABERS 5*, and WELL Platinum across one delivery.

LaSalle Investment Management is the developer and asset manager. Fletcher Priest Architects led the design. Multiplex Construction Europe is the main contractor under a design-build delivery model awarded in early 2024.

Project Scope

The scope is structural retention plus a comprehensive re-skin. Existing concrete frame and core get kept and reinforced. The entire facade, MEP, vertical circulation, and tenant-floor layout get replaced. The completed building fronts both Bishopsgate to the south and the recently re-landscaped Exchange Square public realm to the north, a configuration that turns what was a single-aspect 1990s tower into a building with two equally weighted commercial frontages.

Staticus is delivering the unitized facade under one of its largest UK sub-contracts to date, working directly with Fletcher Priest and structural facade engineer Eckersley O’Callaghan on the design, fabrication, and installation. The new envelope is the single largest contributor to the project’s operational energy performance, and the geometry of the building’s column-free office floors only works because the facade is doing significant structural work.

• 13 floors above ground, with floors 1-13 office (typical floorplates roughly 33,000 sf)
• 430,000 sq ft Class A office plus 17,000 sq ft retail
• Ground-floor retail and lobby plinth animating the Exchange Square edge
• Unitized aluminum and glass facade by Staticus

Why It Matters

By retaining 90% of the existing structure, LaSalle and Fletcher Priest are claiming roughly 50% lower embodied carbon than a new-build equivalent, a comparison that’s becoming the central benchmark for City of London commercial schemes as the Greater London Authority tightens its embodied-carbon disclosure rules.

Three things make this project a particularly visible test case. First, it’s full retrofit but at premium rents. The leasing assumption is that BREEAM Outstanding and NABERS 5* command the same rent as a new tower, not a discounted rent for a “refurbished” asset. Second, the WELL Platinum target sets a high bar for indoor environmental quality on a building whose structure pre-dates modern ventilation design. Third, the project is a near-term comparable for every Broadgate-area landlord weighing retain-or-rebuild on similar 1990s assets.

If the leasing case holds at handover, the embodied-carbon retrofit thesis stops being a sustainability story and starts being a rent story. That’s the version of the argument that actually moves the next round of decisions across the City office market.

Project Team & Details