Currently under construction, Te Ao Nui is a three-storey commercial development (with a total gross floor area of 5200m²) by Manawatū-Whanganui Regional Council Holdings Ltd (MWRC Holdings Ltd) which has been designed with resilience and sustainability in mind.
On a day to day basis, the building will provide office space for its anchor tenant, a 200-staff government agency, along with retail and cafe spaces on the ground floor. Importantly, in the case of a natural disaster — including during a one in 500 year seismic event, the top level of the building will serve as an emergency operations facility for both Palmerston North City Council and Horizons Regional Council with the capacity to operate off the grid for 48 hours through its own supply of drinking water, wastewater storage and power. Designed to Importance Level 4 (IL4), Te Ao Nui is the first and only IL4 office building in the Palmerston North area, providing critical infrastructure for the region.
"In addition to resilience, sustainability was a key requirement for both MWRC Holdings Ltd and the lead tenant. MWRC Holdings Ltd were keen to embrace sustainable technology to demonstrate and ensure efficiency gains were achieved for the people of the Horizons (Manawatū-Whanganui) region,” says Hugh Evans, Senior Mechanical Engineer, WSP.
To provide sustainable hot water for the building, the project team looked for a solar hot water system, ultimately selecting the Apricus ETC30 system due to its excellent efficiency. “What Apricus offered that was beneficial for the space was the evacuated tube compact ETC format — a highly efficient tube configuration for transferring heat to the water in the circuit,” says Hugh. “It takes solar gain and transfers it into hot water. It’s a very efficient set up.”
A commercial solar hot water system comprising twelve Apricus ETC30 evacuated tube solar collectors on pitched frames was specified to meet hot water demand for the building’s 200+ tenants. New Zealand made Apricus duplex stainless steel solar preheat and gas reheat hot water cylinders were also provided as part of the specification, ensuring sufficient supply should there be extra demand on the system. A full control system with building management system (BMS) integration and remote monitoring has been set up to help MWRC Holdings Ltd track energy performance.
With performance modelling and engineering expertise from the Apricus design team, the specification and design process has gone very smoothly. “Apricus have given good input all the way through the process,” says Hugh. “We’ve received good insight to the technical capabilities of the ETCs, and feedback on our design integration and the design build. We’ve also had good feedback so far from contractors working with Apricus.”
The Apricus solar hot water system will continue to provide hot water if there is a break in the gas supply, such as potentially during a natural disaster. The solar system controls will operate on the emergency power supply, concentrating all solar heated water in to the smaller reheat cylinder. This will be backed up by a small electric water heater in one bathroom block for emergency staff. The Apricus system improves the building's resilience by delivering up to 24 kilowatts of water heating whilst using only 100 watts of electricity.
The Apricus solar hot water system is complemented by a host of sustainable features which work together to minimise the environmental impact of the building. These include sensors and daylight harvesting, provision for photovoltaic cells for electricity and electric vehicle charging capability.
Set to open in October 2019 — just 18 months after initial groundworks by the main contractor McMillan Lockwood began — the balance of sustainable and resilient features of Te Ao Nui make it a significant addition to Palmerston North. The ability to reduce reliance on energy in the day-to-day, while maintaining functionality in cases of emergency make the building a pivotal investment for the region.
Architects: WSP New Zealand Limited
Engineering: WSP New Zealand Limited
Solar Hot Water System: Apricus
Main Contractor: McMillan Lockwood
Mechanical Contractor: Air Dynamics
Developer: MWRC Holdings Ltd.