The design brief for Ukaria Cultural Centre, an impressive concert hall located just 40km from the Adelaide CBD, sought an intimate venue for chamber music incorporating exemplary acoustics.
Designed by Anton Johnson Architects, the multipurpose auditorium is a musical instrument in itself. The roof employs the structural principles of the ancient reciprocal frame, featuring composite solid timber rafters with a steel web plate. Externally, the sweeping composite timber and steel veranda rafters fan up over the deck to embrace the rising mountain views. Every timber rafter, floor finish, wall surface, shape, element and plane work together to create the interior acoustic.
All timbers were selected for their sustainable qualities. The auditorium has a spacious and enveloping sound with musicians acknowledging its fullness, clarity, richness and warmth.
Floor system: Reinforced concrete raft footings finished with solid Blackbutt timber floorboards on battens make up the flooring on 80 per cent of the area. The Blackbutt floorboards are 130mm wide, glued and secret nailed to a 20mm structural plywood underlay fixed over timber battens at 450mm centres. This is a sprung floor designed to have rigidity while having spring for the acoustics.
Vertical support or wall system: This consists of a primary structural steel frame with timber framed walls and stepped bulkheads. The wall framing is completely timber. For acoustic purposes, the inner wall framing to the auditorium is required to be very stiff with linings of 25kg/m². Wall framing is 120mm x 45mm at 300mm centres for the inner wall frames to the auditorium supporting 32mm thick plywood linings made of 20mm structural plywood and 12mm hoop pine plywood. Outer wall frames are 120mm x 45mm at 600mm centres supporting external linings of corrugated COLORBOND and 9mm Ecotec FRC panels on steel.
Roof system: Composite solid timber and steel rafters using the reciprocal frame structural system make up the entire roof. Solid Oregon timber beams are bolted on each side of a steel web plate to form a composite timber/steel rafter. Solid Oregon secondary rafters span between the primary rafters. Structural plywood is used as a bracing sheet over the top of both rafters and secondary rafters. Hoop pine plywood panels, set at variable depths for acoustic sound diffusion, are fitted into the reciprocal pattern of the roof to complete the acoustic enclosure of the auditorium.
Cladding: Vertical tongue-and-groove jarrah boards are used for the exterior cladding.
Deck: The external decking is made of 130mm x 30mm forest red mahogany left to silver naturally. The deck is wide with gradual steps down to the gardens. The auditorium opens directly onto the deck, which is used to host additional functions or for alfresco dining, linking the interior with the outside.
Pergolas: Solid Blackbutt beams on CHS steel columns clad with solid Blackbutt boards stained jarrah red. The alfresco space has an extended pergola covered area and pizza oven for outdoor dining.
A glass wall faces the summit and garden. Blade walls of rammed earth frame views of the vines. The auditorium has been designed for fine acoustics with the space serving as an extension of the musical instruments. The acoustics are recognised, with commentators stating that there is no comparable chamber music space in Australia.
Every timber finished wall and bulkhead surface in the auditorium is detailed to have an acoustic function. The ceiling design features timber and steel composite beams interlocking at the crown. The reciprocal frame structure distributes load from rafter to rafter, each supporting the next in a continuous transfer of load. The ceiling embodies energy, balance and visual rhythm – all at the same time. Each segment is divided into smaller panels with varying depths for sound diffusion.
Tongue-and-groove solid Blackbutt timber floorboards on battens make up the floor on 80 per cent of the building area. The utility areas are finished with tiles.
Internal panelling: Hoop pine veneered plywood with yellow cedar framing boards, battens and trims is used for the interior panelling. Additional trims are red gum. Bulkheads are lined with solid yellow cedar boards of varying thicknesses. All the wall and ceiling planes are designed for the concert hall's acoustics.
Architrave: Tasmanian oak and jarrah.
Doors: Tongue-and-groove expressed joint, ship lapped, solid yellow cedar boarded doors.
Joinery and cabinetry: The greenroom joinery features silky oak veneers and solid Tasmanian oak trims and frames. The alfresco bar features joinery in solid red gum boards with silky oak veneers and local granite benchtops.
Rails and balustrades: Stainless steel handrails and frameless glass balustrades.
Photographer: Randy Larcombe
Builders: Harrold and Kite
Architects: Anton Johnson Architects