The Building

DEVELOPER THE WOOLSTORE GROUP

ARCHITECT CMA+U, MACKAY CURTIS

SERVICE ENGINEER 335

STRUCTURAL ENGINEER DUNNING THORNTON CONSULTANTS

QUANTITY SURVEYOR ORTUS

CONSULTANTS HOLMES FIRE; TONKIN + TAYLOR

Kai Tahi is a new symbol for Porirua to re-orientate and connect the town to the sea. The building comprises a 600sqm arcade linked to a 1700sqm retail market hall that initiates a new urban pedestrian system.

The project is a combination of two design strategies. 

  • The first involved the transformation of the existing commercial building, respecting the industrial sheds material and spatial qualities to improve its performance and sustainability. 

  • The second is a new approach, utilising renewable materials
    and sustainable systems such as renewable energy, water harvesting and digital fabrication. 

Reuse of the existing building envelope was a key aspect of the overall design, which minimises the carbon footprint of the building.

Kai Tahi’s services were designed from the initial concept to be driven by sustainable design principles, which resulted in the building having sensor-monitored actuator passive cooling and ventilation systems, retro-fitted insulation together with thermal mass within the arcade, and water harvesting to tanks fixed like saddle bags to the existing concrete boundary wall. The system provides grey water to toilets and roof gardens. 

With the quality of water in the harbour being Porirua’s most pressing environmental concern, the flow of stormwater into the harbour has been attenuated by storage tanks and any concrete removed (to allow the installation of new ground beams) was cut out in clean slabs and repurposed for use on the harbour-restoration project being undertaken by Porirua City Council. 

The large spans of the repurposed market hall provide an expansive space, uninterrupted by structure, that lends itself to a very flexible, multi-tenant environment with few spatial constraints. A clerestory and lanterns bring more sunlight and fresh air to the interior, while the service lane, with a 60m mural by local artist Michel Tuffery, has been transformed into a vibrant, light-filled arcade.