Demolition of existing late C19th closet wing (c.1890) to the south facade and construction of a new, traditionally designed and detailed closet wing to provide wheelchair and ambient disabled access to the Master's Lodge, with an accessible lobby, storage for coats and an accessible Part M compliant wc and the landscaping of the existing Hostel Yard to provide level access to the new closet extension with provision for a refuse store behind the Peterhouse Hostel.

Demolition of existing rear extensions and replacement with single storey link element and one and a half storey extension with associated hard and soft landscaping, alterations to main house including removal of roof lights to front elevation and changes to windows, replacement of garden gates and garden shed