It is understood that the specialists were called in three weeks ago to establish the root of the problems.
One project source said: 鈥淕lass panels have popped out of their frames. It is not known whether the design of the atrium, the glazing or the movement of the building is causing the problems.鈥�
It is understood that the building, which was designed to withstand a bomb blast, was built on a bed of rubber. This means that it moves more than other buildings, and this could be the cause of the problems. 鈥淭he movement of the building could be the cause of the glass panels coming loose because this leads to vibration in the frames,鈥� said the source.
Project director Andrew Makepeace said: 鈥淚 am unaware of any problems with the glazing at Portcullis House.鈥�
Experts say that one remedy could be to install a multilayered film and battening system. A source said: 鈥淏attens could prevent filmed glazing from leaving the frame by trapping the film to the frame.鈥�
Portal, which installed the 拢3m atrium, was unavailable for comment.
Portcullis House was due to be completed in January 2001 but this has been put back to spring. The project has been dogged by controversy, most notably its high cost, at 拢1.2m per MP. It has also been hit by technical difficulties and a high-profile legal wrangle.
Delays on the building, which sits above Westminster Tube station, were caused by London Underground handing over the site late after it had problems building the station. The failure of concrete stitches connecting sections of precast concrete arches caused further delays.
The building also ran into trouble and extra costs when US curtain-waller Harmon successfully sued the House of Commons for picking a more expensive rival to clad the building. The case is thought to have cost 拢8m.
Portcullis House鈥檚 problems are the latest in a series of glazing failures on high-profile projects.
The Health and Safety Executive ordered London Underground to take extra safety measures at the Jubilee Line Extension stations after a panel crashed on to the concourse at Stratford and another cracked at Canary Wharf. Defects have also occurred at Waterloo International Terminal and the National Glass Centre in Sunderland.
