The works require individual, often purpose made, locking solutions for all types of doors and also purpose made constraints to limit the extent windows to suit a range of windows in the Palace of Westminster. The new locking solutions may require interfacing with the existing automatic fire alarms. Redundant fire escape walkways are to be removed and replaced with safe access measures to allow maintenance and security access. All works ensure that existing means of escape are maintained where necessary. Whilst respecting original materials and construction methods used careful design, specification and installation are required in keeping with the surrounding heritage. The contract will be undertaken in two stages with the second stage not commencing until satisfactory completion of the first. The scope of the second stage may be modified or omitted in whole, or in part, to suit operational requirements.