Otago Boys’ High School redevelopment

We completed an extensive redevelopment project at Otago Boys’ High School, focusing on improving safety, compliance and accessibility while preserving the character of the historic campus.

The first separable portion was to build new external lift shafts, ramps and balustrades to improve access to the school’s three main blocks. With major excavations required next to existing buildings, our in-house engineering team worked closely with the consulting engineers to devise a safe, efficient methodology.

The second stage of works included the construction of a new Main Switchboard (MSB) room and MSB to upgrade the school’s electrical infrastructure.

Finally, we redeveloped the Shand, a two-storey heritage building. Carefully retaining the magnificent Port Chalmers breccia façade, we built new 200mm in-situ concrete walls within the existing structure, supported by significant structural steel upgrades, with the majority of the roof framing and roof replaced. Beneath it all, a completely new subfloor replaced failing piles and addressed contaminated ground. The building needed to be strategically weakened before we could strengthen it, a complex task involving extensive temporary works designed by our in-house engineers.

We’re always careful about asbestos in older buildings. A thorough survey of the Shand building showed Asbestos Containing Material (ACM) in the subfloor, window glazing putty and in the laps of the roofing slate, including friable (Class A) asbestos. All asbestos removal works were undertaken by a licensed removalist under strictly controlled conditions, including the implementation of an Asbestos Removal Control Plan, daily air monitoring and independent clearance inspections, with clearance certificates issued for each affected area before construction resumed.

A key component of the Shand building is the integration of the Kāi Tahu creation story throughout the interior. We worked closely with the client, Mana Whenua-owned consultancy Aukaha, and our carpet, Autex, window manifestation and ceiling subcontractors to find practicable ways to fully express the cultural narrative.

Sustainability was a focus throughout the project, with over 80% of waste by weight diverted away from landfill. We implemented practical initiatives to reduce waste and maximise reuse, including:

• SaveBOARD used for site hoardings, manufactured from recycled plastic.
• Existing concrete balcony removed and crushed for use as concrete fill.
• MEVA formwork systems used instead lieu of single use timber.
• EcoStar roof tiles installed on the Shand building, a lightweight alternative to slate containing 80% recycled material.
• Retex recycled textile matting used as durable corner protection.
• Careful on-site separation and reuse of materials, including lead repurposed into fishing sinkers for our site fishers.
• Surplus and reusable materials returned to the school for use in other areas, including doors and leftover ceiling tiles.

Now a performing arts centre, the Shand building incorporates practice rooms, a bathroom, kitchen, control room and multi-purpose spaces. Additional works included the construction of a new lift and an airbridge connection to the grandstand, plus the removal, reinstatement and refurbishment of the staircase.

We worked on all three separable portions simultaneously, carefully sequencing the work to avoid disruption in the busy school. The project stood out for the excellent relationships we fostered with the school, the client and the consultants, ensuring that the project proceeded smoothly throughout.