Masterton Courthouse
Performance Based Design

Masterton Courthouse

Location: Masterton, New Zealand
Project Duration: 2013
Client Team: Ministry of Justice, NZ Government

In November 2011, the 101-year old Masterton Courthouse was closed. It was deemed unsafe to the public due to the risk of collapse in the event of an earthquake. The 900m2 building required strengthening to 100%NBS and re-roofing. General reconfiguration and refurbishment was also needed to bring the building up to modern standards and allow it to reopen for public use. A structural design had been proposed.

In January 2012, the Ministry of Justice began working with Miyamoto International NZ (formerly Miyamoto Impact) to project manage the building’s earthquake strengthening and refurbishment.

When appointed, we recognised that the structural design being proposed was a very costly option – almost on par with demolishing the existing building and constructing a new courthouse. A peer review was recommended to assess if the proposed design represented the best solution for the Ministry. This review resulted in a new design that would half the cost and complete the work in a shorter time-frame. The Ministry approved the budget for the project and we proceeded with appointing the full design team.

A part of our role was to collate the requirements from the different Ministry stakeholders into a brief that clearly articulated all their requirements. This brief meant the designers were fully informed from the outset. In addition, a clear scope of services and appointments for all consultants was provided, avoiding the need for additional fees.

Seismic technologies deployed to upgrade the building included a seismic retrofit. This used fibre reinforced polymer (FRP) for both in plane and out of plane unreinforced masonry. Performance-based methods (alternate analysis methods) were used to justify existing unreinforced wall

out of plane capacity. This eliminated costly wall strengthening. Learnings from New Zealand and Miyamoto International’s Los Angeles and Milan offices were used in the project’s analysis and retrofit to deliver added value to the Ministry.

Throughout the project, we provided clear leadership. This saw the right design team being appointed, costs controlled and a tender process that got the best outcome for the Ministry. By suggesting a peer review, Miyamoto International NZ’s initiative allowed the Ministry to save 50% on the previous design and saw the Courthouse reopen in early June 2013, ahead of the original time-frame.