City Offices
83–85 Mansell Street
London E1
Client:
Eastmount London Limited
RIBA National Award
John Winter + Assocates, Elana Keats and Associates + Jonathan Ellis-Miller
Completed in 1991, 83–85 Mansell Street is widely regarded as one of the most significant office buildings constructed in London during the early 1990s—a rare example of a City-overspill speculative development that has been roundly applauded by the architectural press for its technical innovation and environmental foresight. It marked the first major independent commission for Jonathan Ellis-Miller, then aged twenty-five and newly qualified, who took complete control of the project when the existing consent and re-designed wholesale. Leading a team including ARUP, he obtained fresh planning and building consents, resolved every technical detail, and delivered the building on programme.
The result was a seven-storey, 35,000 sq ft speculative office development of exceptional clarity and technical ambition. An exposed in-situ concrete frame was deployed as a deliberate passive environmental device, exploiting thermal mass to stabilise internal temperatures long before sustainability became a regulatory requirement. The retained and upgraded basement minimised new construction, while the west façade – a six-storey crystalline prism of planar glazing suspended from a lightweight steel frame with Macalloy tension rods and bespoke spider fittings designed by Ellis-Miller from first principles – introduced om of London’s first significant double-skin façades. The rear elevation employed the capital’s earliest structural glass cladding, a solution that dispensed with conventional mechanically fixed glass and set a precedent for the transparent architecture that followed.
These innovations were genuinely pioneering: the double-skin system simultaneously reduced external noise and generated natural stack-effect ventilation, while the structural glazing achieved unprecedented spans and transparency for a speculative office building of the period.
Critical recognition was immediate and sustained. The building received a RIBA National Award and was selected for the Architecture Foundation’s influential City Changes exhibition (1991–92). Nikolaus Pevsner, in the Buildings of England series, described it as “like a draught of pure water”, a cool and crystalline jolt amid the prevailing polyester-suited blandness. Deyan Sudjic, writing in Blueprint magazine, declared: “Ellis-Miller has produced a building of quite exceptional clarity and restraint… a small masterpiece of crystalline modernism.” Catherine Slessor, in the Architectural Review, hailed it as “a technological coup de théâtre”, praising its audacious fusion of engineering and elegance that transformed a modest infill site into a beacon of modernist restraint. Richard Rogers later acknowledged its influence on his own work at Royal Mint Court.
More than three decades on, while many contemporaries have been demolished, 83–85 Mansell Street remains strikingly contemporary in appearance and performance – enduring proof of the vision and technical mastery that Jonathan Ellis-Miller has consistently demonstrated throughout his career.
