Britomart East, Britomart Precinct, New Zealand

Britomart East Buildings are located in the heart of Auckland's Britomart Precinct. The project is a premium office development located directly above Britomart Train Station, comprising two 15,000 square-meter (161,460 square-feet), high-grade office buildings with ground floor retail and a further three levels of offices above. At the time, this development had the largest office floor plate in Auckland. Both office buildings have a Green Star NZ – Office Design 5 Star Rating.

Britomart East includes enhanced public spaces with a central atrium complete with an Ethylene tetrafluoroethylene (ETFE) roof solution. EFTE is a transparent polymer, which is durable, highly transparent, and very lightweight in comparison to glass. This roofed area provides a covered retail experience on either side of Te Ara Tahuhu Lane and links Britomart East with the Central Post Office (CPO) in the West and Britomart car park in the East.

Interface with the Britomart Train Station
Six of the eight main structural grids are directly supported from the train station structure. As noise and vibration consultant, Tetra Tech undertook extensive precinct testing of rolling stock immediately above and at significant distances from the station and tunnel throat. The vibration study was utilized as the basis for the vibration isolation of the building via the introduction of elastomeric bearings between the ground floor support beams, the supporting column heads, and other bearing points.

The commercial space is built around two isolated train station exhaust discharges.

Exhaust and other noxious discharges were also carefully located so as not to contaminate the station’s outside air intakes.

The station escape, right of access, security, and continuity of operation of the East Buildings pedestrian entry/exit were not compromised by the development.

Efficient Systems
The office buildings are designed with a Variable Air Volume (VAV) air conditioning system incorporating high efficiency chillers and boilers, combined with a high-performance facade to provide energy efficient operation and maximize occupant comfort. Intelligent cooling controls maximize the free cooling provided by outdoor air to reduce chiller load.

Rainwater harvesting incorporated into East 2 Building is used for toilet flushing and garden wall irrigation, reducing both demand for mains water and stormwater runoff.

Green Walls
Green walls were installed in the atrium of the Britomart East Complex, and at three stories high, they are New Zealand’s largest living walls.

Computer Modeling
Modeling has been carried out throughout the design process to optimize the HVAC design through assessment of energy consumption and thermal comfort levels and advise the design team regarding facade, daylight, and solar gain.

Green Star
All three buildings were awarded 5 Star Green Star – Office Design V1.

Image courtesy of Patrick Reynolds