Why we are doing this work
Wellington Town Hall is one of the city’s grandest, most important and well-used heritage buildings. Opened in 1904, it's a listed heritage building in the District Plan and has a New Zealand Historic Place Trust Category One, which means it has high cultural and heritage value for the city.
The Town Hall's main auditorium’s acoustics are known as among the ten best in the world, especially for symphonic and choral works.
Wellington Town Hall from Civic Square
The Town Hall is an earthquake-prone building, meeting just 20 - 25 percent of the current building code.
The two main factors that make the building earthquake-prone are:
- it was built in the 1880s on reclaimed land - mainly uncompacted fill from the cliff face in Lambton Quay, hauled to the site by horse and cart. In a significant earthquake, it would be prone to liquefaction
- its foundations are over 100 years old. Constructed from unreinforced masonry (brick) walls with a stone plinth around the base, the building sits on its original unreinforced concrete piles.
The strengthening project will rectify these two things.
Why we chose base isolation
We considered several options for strengthening the Town Hall and decided to go with base isolators - special pads that move and stretch, helping to absorb the impact of an earthquake and keep the building safe.
Base-isolation was chosen because:
- it will bring the building to 140 percent of the new building standard so:
- Wellingtonians and visitors can continue using it for events
- it can house the Council chambers and mayoral office
- it means less strengthening work is needed on the building itself, so we can retain its heritage features and value
- it will protect the hall's exceptional acoustics
- being so resilient, it could act as a safe venue for welfare or recovery operations after a major earthquake.
For more information on base isolators, see:
Town Hall Strengthening - Base Isolation
Plan of work
To install base isolators in the Town Hall, we will need to:
- remove and carefully store the grand organ (installed in 1906) before strengthening the wall behind it - for more information: Town Hall Organ
- remove some of the internal walls and ground floor
- install new foundations
- drill holes up to 20 metres deep for the sheet piles, which keep water and earth from the construction site
- remove 3,000 cubic metres of soil from the site
- install over 300 new reinforced concrete piles
- install 132 base isolators to reduce swaying, shaking and damage in an earthquake
- lay a new concrete floor with the original matai flooring and replica tiles re-laid on top.
When the work is finished, everything inside will be put back. The Town Hall will look just like it does now, but it will be stronger and safer.
Using scanning technology to determine accuracy and options
View the animation of the Town Hall created by Holmes Consulting:
Wellington Town Hall - Preserving History with New Technologies - Holmes Consulting Group
This demonstrates one of the best tools to get accurate building measurements. Once the building is scanned, the data is imported into 3D drafting software to determine strengthening options. The architects can then use the actual dimensions in their drawings to create 3D models.
Time frame and project budget
The project will take up to 3 years to complete.
The Council has a budget of $47 million to strengthen the Town Hall. This includes a NZ Lotteries grant of $847,900 towards organ restoration costs.
Alternative venues for use
While the Town Hall is closed for strengthening, alternative venues are available for public and civic use, including the Michael Fowler Centre and the newly upgraded Shed 6 on Queens Wharf. If you would like to enquire about alternative venues, contact:
Positively Wellington Venues
Council meetings - which usually happen in the Council Chamber upstairs - will be held elsewhere.
Phone: (04) 803 8203 or 021 227 8203