Replacement of the existing windows and external doors with Option A new aluminium-d, thermally-broken argon-filled, low-emissivity double-glazed units, including all necessary mullions/support structure to suit the existing window openings and including all associated restrictor & teleflex winder-opening mechanisms, along with upgrade to reveals including; insulation / air-tightness, making-good to cill boards and new reveal/head liner panels and new black out blinds to all windows in teaching spaces. Tenderers are hereby requested to submit an Option B tender for the supply and installation of a Upvc double glazed windows (only) in place of the specified thermally broken aluminium system. It is intended to issue letter of intent for the works in late May 2022 so that the windows can be measured on site, manufactured and available for installation commencing end of June 2022 with full project completion of all works by 19 August 2022. All tenderers are advised to include for all necessary resources to complete all aspects of the project during the 2022 summer holiday break period. Contractor shall note works cannot take place during normal school hours and Contractors must allow sufficient resources to allow the works to be completed within the programme time constraints.