The historic Graythwaite Estate in North Sydney has been redeveloped as an extension of the Sydney Church of England Grammar School (SHORE) adjacent campus. The project comprised the conservation and adaptive reuse of the Heritage-listed Graythwaite House and its outbuildings, the construction of new educational buildings and the enhancement of the site’s parkland setting. Graythwaite Estate Stage 1 forms a major part of implementing the 15-year master plan being undertaken by SHORE with the opening of Graythwaite House in 2014 marking the 125th anniversary of the school.
ACOR Consultants was commissioned to assist in the detailed investigation and design of structural elements and the stormwater (surface and sub-surface) drainage system to prevent ongoing water damage to the substructure. Structural engineering input was provided to bring the superstructure up to current standards of design and safety. All the civil and structural engineering works were successfully completed in sympathy with the heritage aesthetic. A key challenge was to upgrade the buildings and facilities to meet current standard and code requirements but still maintain the heritage fabric.
The technical aspects of the engineering investigation and design included groundwater investigations and design of a surface and subsoil drainage system to protect the building, basement and foundations from further water damage and deterioration. This involved elements of deep curtain ground drains coupled with perimeter French-drains and enhanced surface runoff capture and conveyance around the house.