Bowen Campus

Situated in the Bowen business district (Parliament) in Wellington, Bowen Campus was designed to house a mixture of commercial and public sector clients.

Services

• Three water and utility infrastructure upgrades

• Structural engineering

• Seismic systems

Stormwater infrastructure upgrade

A key challenge was the decommissioning of an existing 800mm diameter stormwater main traversing the site, which was replaced with a 900mm diameter pipeline. The alignment was complicated by limited cover due to upstream and downstream tie-in constraints, requiring flatter gradients in certain sections to maintain minimum cover and hydraulic performance.

To mitigate structural loading on the new pipeline, our civil and structural teams designed a reinforced concrete bridging slab at the northern end of Bowen Lane. This solution redistributed surface and structural loads away from the pipe corridor, ensuring long-term durability.

Structural and seismic engineering

Our structural engineers provided comprehensive design services beyond utility protection. This included seismic restraint systems for non-structural building elements, as well as structural design for landscaping features such as retaining walls and external staircases. These designs were developed in accordance with NZS 1170 and all other relevant structural and seismic performance standards.

Regulatory compliance and construction support

Harrison Grierson prepared all documentation required for building consent, ensuring compliance with local authority requirements. During construction, we provided ongoing technical support, site inspections, and certification services to verify that works were completed in accordance with design intent and regulatory standards.

Civil design and coordination

Our civil engineering scope encompassed detailed design and documentation for site-wide earthworks, stormwater and wastewater drainage, utility services, and sections of the hard landscaping. We worked closely with our HG surveying team to verify the location and depth of Wellington’s Main Sewer Interceptor (MSI), which exceeded five metres in depth in some areas. This information was critical for designing safe and effective lateral connections from both 40 and 44 Bowen buildings.

Strategic sewer connections

We coordinated a connection for 40 Bowen to an existing downstream manhole on Bowen Street, aligning with concurrent works by Wellington Water and Stantec, mitigating risks associated with connecting to a developer-installed manhole inside the property.

Initial plans to connect 44 Bowen via an existing lateral on Ballentrae Place were complicated by the absence of as-built records. Following CCTV inspection and site investigation, we developed an alternative solution within a congested service corridor. Our structural team also advised on the integrity of a core sample from the MSI and provided a safe structural solution to support lateral connection feasibility.

Risk management around critical infrastructure

Given the MSI’s fragility—highlighted by a collapse in 2019 and a drilling incident in 2022 at other sites - Wellington Water imposed strict controls. Our Surveying team helped established exclusion zones to prevent plant activity above the interceptor, as well as vertical movement monitoring of the MSI itself. LT McGuinness developed a robust construction methodology with multiple contingency plans to address potential MSI failure scenarios, of which the exclusion zone and monitoring formed an integral part.

Integrated design and digital coordination

Dunning Thornton’s bridging beam design ensured building loads were isolated from the MSI. Our team coordinated service alignments around these structural – and other disciplines’ - elements using IFC models from the structural and building services engineers. This digital coordination enabled real-time design adjustments, such as advising on required piles repositioning and bridging beams extensions to resolve clashes with wastewater laterals.

We also ensured precise placement of stormwater laterals through corbel walls, avoiding conflicts with adjacent infrastructure, including grease traps, ducting, and other pipework.

Quality assurance

Our team conducted detailed inspections of manhole installations and finalised all defect rectifications to ensure compliance with design and performance specifications.

Awards

• 2024 NZIA Branch Award

• 2024 Property Council New Zealand RCP Commercial Office Property Award - Excellence

• 2024 Registered Master Builders Master Builders Commercial Building Awards - Gold

Talk to our Structural Team today to learn how Harrison Grierson can help bring your next infrastructure project to life.