British Museum Tender for £9m Reading Room Roof Conservation

The British Museum is seeking to appoint a principal contractor for £9 million roof repair and replacement works to its famous Grade I listed Round Reading Room.

The Round Reading Room was designed by Sydney Smirke and completed in 1857. It is a structure of exceptional national heritage significance.

Raised panels, gilded mouldings and its iconic dome are the surroundings associated with such Victorian thinkers and writers as Darwin, Dickens, Marx and Woolf.

Nex-Architecture, which is overseeing the roof works, comments: “The building was as technically ambitious as it was beautiful. Spanned in wrought and cast iron, its original ventilation system drew fresh air up through vaulted brick tunnels under the floor and out through desks to the lantern above, an act of environmental ingenuity well ahead of its time.”

By the turn of this century, that system had fallen dormant but Nex plans to renew the ventilation system using discreet automated controls.

The original ventilation grilles in the readers’ desks at floor level will be upgraded, restoring and enhancing the stack-effect strategy Sydney Smirke had originally devised.

Reading Room Roofs

The roofs comprise three elements:

• Snow Gallery Roof – a perimeter flat roof
• Copper dome – in batten-roll standing seam
• The 20-sided glazed lantern incorporating patent glazing, timber sidelights, and a decorative internal laylight.

The tender’s works span four main areas:

• Snow Gallery Roof: Removal of an existing membrane and mineral wool flat roof build-up down to the concrete deck. Installation of a warm roof with cold-applied liquid waterproofing membrane, including upstands, penetrations, and new lightning protection.
• Copper Dome Conservation and Repair: a close-quarters condition survey is needed before conservation-led repair from a temporary scaffold, including localised copper panel replacement, seam and flashing repairs, and full replacement of the lantern base apron. Works must be carried out by a heritage-accredited metal roofing specialist.
• Lantern Glazing, Windows and Refurbishment: Full replacement of the existing patent-glazed lantern atop the dome with a bespoke tiered steel glazing bar system; repair and redecoration of external windows and internal sliding sashes; installation of BMS-linked actuators; and in-situ conservation of the historic internal laylight.
• Maintenance Access and MEP: Upgrade of permanent access provisions including fall-arrest and restraint systems, internal walkway refurbishment, replacement heating, LED lighting, and BMS integration.

The project includes a number of contractor’s design portion (CDP) items, including scaffold and temporary works, tiered patent glazing, access systems and mechanical, electrical and plumbing (MEP) systems.

Project Challenges

Access will present a challenge for the contractor as the Round Reading Room is entirely enclosed, with no direct external crane access.

The British Museum also hopes to keep the Round Reading Room open to staff and public for the maximum time possible during the works. Noise and vibration limits apply.

Protection of the Reading Room interior and collections is also critical. A Stage 4 design for a cable-restrained scaffold system and temporary roof has been developed.

Asbestos and lead-based paints are both confirmed present within the lantern and on historic ironwork.

Architect image of the renewed copper roof and lantern glazing (courtesy of Nex-Architecture)

Procurement Programme

The project will be procured via a single-stage traditional tender under a JCT Standard Building Contract 2024 with Contractor’s Design Portion.

A contractor will be selected on capability, heritage experience, and commercial submission, with appointment aimed for November 2026, a start on site in January 2027 and Practical Completion targeted for Q1 2028.

Contractors will be required to demonstrate CDP and construction experience across: conservation of Grade I or II* listed structures; heritage metal roofing; liquid-applied roofing; bespoke patent glazing fabrication; heritage window joinery and ironwork; works within live occupied public buildings; and complex temporary works in constrained environments.

Tenderers must be registered as suppliers on the Find a Tender system.

Submission through the Delta eSourcing portal by 15:00, Monday 19 October 2026. The estimated award date is 30 November 2026.

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