Seismic strengthening

Wellington Trades Hall is an important building in the history of the labour and union movements in Wellington. It is listed in WCC’s heritage inventory.


It was deemed earthquake prone in 2012.


The owner, Wellington Trades Hall Incorporated, asked us to co-ordinate the seismic strengthening to achieve 34% NBS or better. We worked with Don Thomson Consulting Engineers to design a sympathetic solution that considered the heritage fabric, adjacent heritage shopfronts and pedestrian traffic.

The main component of the scheme was the new shear walls at the main entry at 124 Vivian Street. Site work started with the partial demolition of foyer and façade nib walls, followed by excavation for a new concrete ground beam. Two anchor piles were drilled to 18 metres and 15.1 metres. Thick shear walls and PFC collector beams at ceiling level were installed in the foyer and two adjacent tenancies. Grooves were formed in the shear walls to match original concrete detailing.

Where the foyer walls were demolished, infill timber walls house the 1927 foundation stone and the Samuel Parnell memorial plaque, two important artefacts in the history of the Trades Hall. 


New reinforced concrete floor nib walls at the façade reinstate the original shopfront configuration. New painted timber windows and doors were installed in the two adjacent shops.


Lighting designed by Stephenson & Turner included LED strip up-lighting around the cornice and spotlights on plaques and new paintings in the foyer and lobby.


New floor tiles to match the existing were installed where we excavated for the ground beam. On the infill walls, modern, sympathetic handmade tiles are a match to the original main wall tiles. A fresh coat of paint on the foyer walls to the non-tiled area brightens the space.

The Prime Minister, the Right Honourable Jacinda Ardern, formally re-opened the building on 27 March, 2018. Trade unionists, building tenants, the mayor, WCC councillors, consultants and contractors gathered to celebrate the success of the project.

'Heritage Today' newsletter featuring Trades Hall project:


True Crime: The Trades Hall Bombing - Radio NZ - Afternoons with Jesse Mulligan 19 March 2020


heritage shopfront
heritage shopfront
heritage leadlights
Wellington Trades Hall Vivian Street