Mace Construct is returning to one of the most recognisable buildings it has delivered in London, beginning work this month on the reported £150 million transformation of the former City Hall at More London. The contractor originally delivered the wider More London development, including the riverside landmark, which completed in 2002. Twenty-four years later, Mace has been appointed by St Martin’s Property Group to expand and reposition the vacant building at 110 The Queen’s Walk as a modern office, retail and public-realm destination.
The project matters beyond its contract value. It demonstrates how London’s retrofit market is moving away from light refurbishment and towards deep intervention in existing buildings: retaining the recognisable structure while replacing the façade, renewing services, altering floorplates and changing how the asset works commercially.
Former London City Hall at 110 The Queen’s Walk, photographed by London Construction Magazine before the main redevelopment works began.
London Construction Magazine Insight: The former City Hall project shows what “retrofit first” increasingly means in practice: major structural, façade and services intervention inside an existing landmark, rather than a simple upgrade of finishes and plant.
Mace Returns to a Building It Delivered 24 Years Ago
Mace’s return gives the project an unusual continuity. The contractor delivered the original More London development over a ten-year period, creating a 13-acre commercial district containing six plots, public space, shops, restaurants, The Scoop amphitheatre and the former Greater London Authority headquarters.
The building became one of the capital’s most recognisable modern civic landmarks, positioned beside Tower Bridge and overlooking the Thames. The Greater London Authority left the site after exercising a lease break in December 2021, relocating City Hall functions to the Royal Docks. St Martin’s Property Group has since examined how the vacant asset could be returned to productive use while maintaining its significance within the London skyline and the wider More London estate.
The Project in Numbers
| Project Detail | Current Position | Construction Significance |
|---|---|---|
| Reported project value | £150 million | A major London commercial retrofit rather than a routine refurbishment. |
| Existing and proposed area | Expansion from approximately 18,000 sq m to 22,000 sq m | Requires more usable floor area to be created around the retained landmark form. |
| Client | St Martin’s Property Group | Long-term repositioning of a high-profile asset within the More London estate. |
| Main contractor | Mace Construct | The original delivery contractor returns to manage the building’s next major phase. |
| Design and engineering | Gensler, with Waterman providing engineering support | Architecture, structure and building services must be integrated around retained fabric. |
| Start | July 2026 | Moves the redevelopment from planning into physical delivery. |
The Building Will Be Retained, but Almost Every Major System Will Change
The redevelopment will preserve the building’s circular footprint and curved silhouette, but the intervention is extensive. Mace’s announced scope includes replacing the existing cladding and glazing, creating new terraces, changing the roofscape, infilling the atrium and fitting out the building to shell and core with new mechanical, electrical and plumbing systems.
Modern end-of-trip facilities will be introduced, while the ground floor will support a more open mixed-use offer. Gensler’s design is intended to bring cafés, shops and restaurants into the building and increase activity along Queen’s Walk.
This combination highlights a central truth of major reuse projects: retaining the building does not necessarily mean retaining its existing envelope, internal organisation or operational systems. The embodied-carbon benefit comes from preserving valuable parts of the structure, but the delivery risk moves into the interfaces between old and new.
Façade Replacement Will Define Both the New Appearance and the Programme
The existing glazed envelope is one of the building’s defining characteristics, but it is also central to the need for transformation. Full façade replacement means that architectural identity, thermal performance, weather protection, access, temporary works and structural interfaces all have to be managed together.
The project is therefore likely to involve significantly more coordination than the phrase “refurbishment” suggests. Existing geometry must be verified, interfaces opened and understood, new loads transferred safely, and temporary weathering maintained while the building envelope is progressively removed and rebuilt.
London Construction Magazine has previously examined why office retrofit strip-outs are exposing hidden building conditions. At 110 The Queen’s Walk, the prominence and geometry of the façade increase the importance of early investigation, accurate records and tightly controlled sequencing.
Expanding Floorplates Changes the Commercial Logic of the Landmark
The planned increase from approximately 18,000 sq m to 22,000 sq m is not only a design adjustment. It addresses one of the commercial weaknesses of distinctive civic buildings: an iconic external form does not always produce efficient, flexible workplace floorplates.
By extending the accommodation around the existing structure and infilling the atrium, the redevelopment aims to create more usable office space while retaining the visual memory of the original building. This is a recurring London retrofit challenge—how to preserve enough character to justify reuse while changing enough of the asset to meet modern occupational and investment expectations.
A similar balance between retained structure, additional area and high-performance office requirements is visible at 75 Davies Street, where McLaren is expanding an existing West End asset above live transport infrastructure.
Public Realm Is Part of the Construction Story
The scheme extends beyond the building itself. Improvements are planned around The Scoop amphitheatre, surrounding green space, the riverside walk and the southern edge of the estate. Project information indicates that approximately 10,000 sq m of public realm will be reimagined, with increased planting, new seating and lighting, and stronger green connections towards Potters Fields Park. That creates a complicated interface between private construction works and one of London’s busiest public riverside routes.
Pedestrian management, deliveries, hoarding, public access, event coordination and the continued operation of surrounding buildings will therefore be part of the main programme—not secondary considerations outside the site boundary.
Why This Project Matters to London’s Retrofit Market
The former City Hall redevelopment arrives as London’s premium office market increasingly favours high-quality, low-carbon space while older assets face pressure from occupier expectations, energy performance and inefficient layouts. In this environment, reuse is becoming a commercial survival strategy as much as a sustainability strategy. Owners are retaining structure where it creates value, but undertaking increasingly heavy intervention to achieve competitive floorplates, façades, services and amenities.
London Construction Magazine’s London Office Retrofit Master Guide identifies exactly this shift: the most important question is no longer whether an office can technically be upgraded, but whether the design, investigation, cost and construction sequence can make the upgrade commercially deliverable.
The Practical Test Will Be Delivery Certainty
The architectural proposition is compelling: preserve a London landmark, create more efficient commercial space, improve public access and reduce the need for full demolition and replacement. The construction test is harder. Mace must coordinate retained structure, major envelope replacement, new MEP systems, floorplate expansion, atrium intervention and public-realm works inside an exposed and heavily used riverside location.
Its history with More London gives the contractor an unusual connection to the asset, but the building being returned to market is not the building Mace completed in 2002. Modern performance standards and commercial expectations require a deeper transformation. If delivered successfully, the project will provide an important London example of how a recognisable modern landmark can be adapted without defaulting to complete demolition. It will also show the level of technical and commercial intervention now required to make “retrofit first” work at the top end of the capital’s office market.
Sources and methodology: This article uses Mace Construct’s appointment announcement, Gensler’s published project information, London City Hall records concerning the GLA relocation, and publicly reported project-value and engineering information. The delivery-risk interpretation is London Construction Magazine analysis. Sources: Mace Construct project announcement; Gensler project profile; London City Hall relocation announcement; and B&CO project summary.
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Expert Verification & Authorship: Mihai Chelmus
Founder, London Construction Magazine | Construction Testing & Investigation Specialist |
