STRUCTURAL ENGINEER'S REPORT
The structural concepts which make up the Pier Arts Centre presented different engineering challenges of conservation, renovation and new build, but none greater than the integration of all three to create the linkages necessary for the centre to function effectively. The existing Pier gallery building is an early-19th-century B-listed stonebuilt pier warehouse converted in 1978 by Levitt Bernstein.
Conservation focused on essential structural repairs and timber-truss adaptations to form openings for links to connect with the new-build adjacent gallery. The Victoria Street buildings, consisting of two stone-built 18th-century town houses, were combined to provide the entrance, reception, administration spaces and accommodation for meeting rooms. Structural works comprised substantial demolition and rebuilding to accommodate the new building extension; a full-width opening connecting the street buildings at ground oor by permanent removal of the dividing gables; and rebuilding the original first-floor - replace, ue, chimney stack and ridge stonework, all suspended on a steel frame. Large openings in front and rear elevations were framed out with in-situ concrete.
Floors, originally constructed using timber-pole joists and sagging alarmingly, were replaced with new timber joists on steel UC section beams to minimise depth and maintain headroom. The new gallery building provides galleries, circulation space and back-of-house functions. Timber and steel-frame structures with timber or light steel walling were all considered until the need to create varying volumes, clear spans, large openings and cantilevers with very limited slab depths and wall widths informed the decision to use in-situ concrete construction. This in turn contributed to the architectural finishes in the form of board-marked columns and ceilings sculpted to minimise the impact of lighting tracks. Concrete walls and oors provide lateral stability, but also distribute the building load to concrete piles bored to bedrock through loose rock-fill behind the original pier walls. Constrained as the site is by Victoria Street to landward and the harbour to seaward, with minimal space between, site access was a challenge which was eventually met with the help of local contractor Casey Construction. The concept of creating the site compound and access by temporarily infilling a section of harbour was realised using second-hand large-diameter steel tubes to build a new temporary harbour wall.