Town Hall restoration takes 4 years
Restoring the Town Hall to its former glory will take four years and cost an estimated $127.5 million.
Christchurch City Council staff today presented four options for repairing the Town Hall to councillors but made it clear they preferred option one - maximum retention and restoration.
Under that option the outside of the building would remain visually unchanged apart from some angle bracing which would be installed around the Boaters Restaurant.
The Limes Room would be retained and restored, and Boaters and the Cambridge Room rebuilt. New lighting, audio visual and sound systems would be installed, the size of the entrance foyer increased, and the acoustics upgraded in the James Hay.
Project director Liam Nolan said the main damage to the Town Hall was caused by liquefaction beneath the building rather than ground shaking.
Engineers proposed increasing the resilience of the building by constructing a new foundation using jet grout columns and a concrete raft.
The auditorium, James Hay and kitchen buildings have strong structural systems and only require relatively minor strengthening works to significantly improve strength.
However, the Limes Room and foyer strengthening is more significant as repairing it needs to address excessive flexibility in existing structural systems. Likewise, the Cambridge Room was significantly damaged and will be demolished and rebuilt.
Nolan outlined option one, which was designed for "maximum retention and restoration".
Nolan said this option included increasing the size of the foyer, new lighting, audio-visual sound systems and upgrading the acoustics in the James Hay.
The preliminary cost was $127.5 million.
The following options were also outlined:
Option 2: Part Retention
Option 3: Full replacement
Option 4: Full replacement
The first two options were considered to maintain the original identity of the Town Hall, while the third and fourth do not.
Council major facilities rebuild manager Mike Hannaway said the only external visible intervention was some angle braces to strengthen the whole block.
Hannaway said all four of the options focused on safety and making the building structurally sound, with heritage and function also taken into account.
"While we are doing this work, and it is a major job, what opportunities are there to tweak and make the building function better?"
Whichever option was chosen, Hannaway said there was other work that would apply.
Hannaway said the first three options were all of similar cost, but the fourth option was a "radical departure" and would save about $2.5m.
Councillors have committed $127.5m towards saving the Town Hall but have yet to finalise the scope and design of the repairs.
They need to do that by the end of this month so a decision can be reached on whether the council will proceed with building a performing arts precinct in the Colombo St-Armagh St area.
The performing arts precinct was one of the anchor projects in the Christchurch Central Recovery Plan, but the Government handed over responsibility for its development to the council in late June as part of their cost-sharing agreement.
The size and the scope of the precinct will depend on what decision the council reaches on the Town Hall because if the repairs cost as much as estimated it will only have $38m left to spend on additional facilities for the performing arts.
Councillors will be doing a walk through of the Town Hall next week Tuesday.
It is expected they will make a decision on the design and repair at a council meeting August 29.