British Museum Round Reading Room Roof Oculus Works

Project Overview

The British Museum is seeking to appoint a Principal Contractor for a programme of essential roof repair and replacement works to the Grade I listed Round Reading Room, located at the centre of the Museum.

Building Context and Heritage Significance

The Round Reading Room was designed by Sydney Smirke and completed in 1857. It is a structure of exceptional national heritage significance, combining iron primary construction with brick masonry, a copper-clad dome, and a fully glazed central lantern. The roofscape comprises three elements: a perimeter flat roof known as the Snow Gallery Roof; the copper dome in batten-roll standing seam; and a twenty-sided glazed lantern incorporating patent glazing, timber sidelights, and a decorative internal laylight.

Scope of Works

The works span four principal 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: Close-quarters condition survey and conservation-led repair from temporary scaffold, including localised copper panel replacement, seam and flashing repairs, and full replacement of the lantern base apron. Works must be undertaken by heritage-accredited metal roofing specialists.

• 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 CDP items, including, but not limited to, scaffold and temporary works, tiered patent glazing, access systems and MEP systems.

Key Project Constraints

• Access and Logistics: The site is entirely enclosed within the Foster+Partners Great Court roof, with no direct external crane access, and the Round Reading Room is to remain open to staff and the public for the maximum time possible during the works. A Stage 4 design for a cable-restrained scaffold system and temporary roof has been developed by an access specialist and needs to be completed as a CDP item, alongside a full lifting, logistics and evacuation strategy.

• Operational Environment: Although temporary periods of closure and exclusion will be possible in the Round Reading Room, the Museum will remain open without restriction throughout the construction period. Noise and vibration limits apply, and protection of the Reading Room interior and collections is mandatory throughout.

• Hazardous Materials: Asbestos-Containing Materials and lead-based paints are confirmed present within the lantern and on historic ironwork. Safe methods of removal must be provided during the works.

Procurement and 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.

Due to the confidential/commercially sensitive nature of information that will be included in the associated tender documents we require that interested suppliers enter into a confidentiality agreement before they are given access to the tender pack. A copy of the confidentiality agreement is available by request via email to procurement@britishmuseum.org. The terms of the confidentiality agreement are not subject to negotiation.