The Senedd building (Welsh pronunciation: [ˈsɛnɛð]) in Cardiff houses the debating chamber and three committee rooms of the Senedd (Welsh Parliament; Welsh: Senedd Cymru, formerly the National Assembly for Wales). The 5,308-square-metre (57,100 sq ft) Senedd building was opened by Queen Elizabeth II on 1 March 2006, Saint David's Day, and the total cost was £69.6 million, which included £49.7 million in construction costs. The Senedd building is part of the Senedd estate that includes Tŷ Hywel and the Pierhead Building. After two selection processes, it was decided that the debating chamber would be on a new site, called Site 1E, at Capital Waterside in Cardiff Bay. The Pritzker Prize-winning architect Lord Rogers of Riverside won an international architectural design competition, managed by RIBA Competitions, to design the building. It was designed to be sustainable with the use of renewable technologies and energy efficiency integrated into its design. The building was awarded an "Excellent" certification by the Building Research Establishment Environmental Assessment Method (BREEAM), the highest ever awarded in Wales, and was nominated for the 2006 Stirling Prize. The Senedd building was constructed in two phases, the first in 2001 and the second from August 2003 until it was handed over to the then National Assembly for Wales in February 2006. Between phases, the National Assembly changed contractors and the project's management structure, but retained Lord Rogers of Riverside as the scheme architect. The building was nearly six times over budget and four years and 10 months late, compared to the original estimates of the project in 1997. Total costs rose due to unforeseen security measures after the 11 September attacks, and because the National Assembly did not have an independent cost appraisal of the project until December 2000, three years after the original estimate. Phase 2 costs rose by less than 6% over budget, and that phase was six months late. From Wikipedia
