The parliamentary office building Portcullis House requires a “complete overhaul” of its roof and has “severe structural failings” in its atrium glazing, warns an official parliamentary report obtained by the Observer.
The new study, commissioned by the parliamentary authorities, warns that rain is leaking into MPs’ offices and recommends roof works likely to cost tens of millions pounds. It suggests an interim measure of adding netting to the underside of the atrium roof “to prevent glass from falling on to people” in the event of cracked panes. The House of Commons said this weekend that netting was being installed in the atrium.
The report, by the architecture firm Purcell, with input from specialist contractors, reveals that the building was not designed with access to the roof for maintenance. It is now likely to require extensive works, despite only being completed in August 2000 at a cost of £235m.
“There is water ingress in many areas, including members’ offices,” says the report. “The main roof needs a complete overhaul in terms of waterproofing and safe access.”
In addition to the works required to the main roof, concerns over the spectacular atrium roof were highlighted when a pane of glass cracked last July, spilling a deluge of water below. The report says the double-glazed unit filled with about 100 litres of water after its seals failed.
MPs have already been told that the building’s electrical and mechanical systems need replacing at a cost of up to £143m. A budget for the roof works has not yet been agreed.
A National Audit Office report in 2002 said Portcullis House had been designed with a lifespan of 120 years. It reported that it had been constructed to a “high standard of architectural design, materials and workmanship”.
It now appears that the building was constructed without providing easy access to the roof for workers. Maintenance requires abseiling teams, and a drone has been used to help visual inspections. “The original design of the building did not fully consider the need for safe access on the exterior of the main roof,” says the report dated August 2023. “Over time, this has led to the lack of maintenance of the main roof and current poor state.”
When the building was constructed, a “track and cradle” maintenance system was installed for cleaning and replacing glass panes. It was only used for a short period and its tracks are now warped. It is recommended that it be replaced.
Sir Charles Walker, chair of the House of Commons administration committee, told MPs in July there have been 12 recorded leaks related to the glass atrium roof and three breakages. The report advises against the continued “ad-hoc” replacement of any cracked glass panes.
It warns: “It has been shown that the rate of breakages and deterioration has increased through time and that it is no longer viable in terms of efficiency to replace these on an ad-hoc basis.” It says that the parliamentary authorities should research the option of replacing glazing in the atrium roof with an “enhanced specification”.
The report states: “The client team may wish to consider interim measures that could be taken to prevent glass from falling on to people within the atrium space below.
“One temporary option would be to add netting to the underside of the roof. Alternatively, a less lightweight solution would be to add a crash deck to the underside.”
The report says glass breakages peaked in summer months. One option to reduce overheating and glare from the sun in the atrium, it says, would be to install a retractable canopy over the roof, similar to covers deployed in sports stadiums.
A House of Commons spokesperson said: “Portcullis House is one of the most heavily used areas of the parliamentary estate. The building remains safe to work in, though as it is now over 20 years old, essential works are required, including repairing and replacing services and systems.
“The feasibility study into the main roof and glass atrium of Portcullis House supports our existing knowledge of the building and the challenges it poses. We have already begun scoping the wider programme of works that will also deliver the necessary improvements to the roof.
“In the meantime, Portcullis House can continue to provide safe, secure, and serviceable facilities that provide sufficient capacity to meet the long-term needs of the House, with parliament’s in-house maintenance team regularly undertaking work to keep the building running.
“External experts have advised that the roof is safe. To provide further reassurance, and as an additional safety mitigation, netting is being installed under the atrium roof ahead of the longer-term and wider programme of works.”
