Colonial House Seismic Strengthening

Following the earthquakes in Wellington in 2013, Government tenants vacated Colonial House in Lower Hutt and it became high priority for Oyster management to strengthen and repair the building so tenants could re occupy.

Colonial House situated in High Street, Central Lower Hutt is a three storey office building constructed in the 1980’s under previous building codes and it was assessed to have a seismic performance of approximately 20% of National Building Standard (NBS). Tenants, Accident Compensation Corporation (ACC) and Ministry of Social Development (MSD) had vacated the property, follow the earthquakes in 2013, although these earthquakes only resulted in minor damage.

Oyster Management Ltd appointed The Building Intelligence Group as the project manager to manage the Colonial House seismic upgrade project with the aim to get the tenants back in the building as quickly as possible, and to secure them as long term quality tenants. The tenants required that building must meet a minimum of 67% NBS and 70% NBS was achieved.

Scope of Work:

  • In-situ concrete foundations and steel frame bracing on ground floor.
  • Steel frame bracing to 1st / 2nd floor.
  • Steel collector and tie rods on 1st / 2nd floor.
  • Bracing/strengthening the pre-cast wall connections on ground floor.
  • Bracing/strengthening the pre-cast and steel column connections on 2nd / roof level at each corner of building.
  • Bracing/strengthening the pre-cast wall steel tie connections on ground to roof (at stairwell).
  • Removal and reinstatement of internal walls, ceilings and services to allow access for the strengthening.
  • Repair of cosmetic earthquake damage.

The 2014-2015 seismic strengthening work on Colonial House has brought it up to 70% NBS as required by the Government tenants and they reoccupied in June 2015. TBIG’s deep understanding of seismic strengthening works ensured that a significant issue with ground quality was resolved quickly by an innovative approach to problem solving that produced a cost-effective solution.