Aorangi House in Wellington is one of the most energy-efficient buildings in New Zealand. Once unoccupied and outdated, it’s now a 5.5 star NABERSNZ-rated green building, using around 64% less energy than the average commercial office.

First built in 1970, Aorangi House was in urgent need of refurbishment. Along with its outdated, leaky façade, there were issues with heating ventilation and cooling, and the building had been vacant for three years.

A complete refurbishment was commissioned in 2008, employing the latest green building principles and major interventions to give it a new lease on life. Beca provided building services, environmentally-sustainable design, lighting, and structural design services for the retrofit, working closely with Studio Pacific Architects to integrate the design.

The design approach placed a focus on the building users, aiming to provide an intuitive and user-friendly environment by maximising the use of daylight, passive cooling and natural ventilation. Green features include plastered thermal insulation on the external walls, solar shading elements, an aluminium double-glazed window system that automatically opens for additional ventilation, optimised heating and cooling, and monitoring systems for power, water, temperature and air quality levels.

Structurally, the building was future-proofed with a high level of seismic strengthening using an innovative yet deceptively simple approach that required 16 steel cables to be installed into pinpointed areas. The building was completed in 2009, with Beca moving in as anchor tenants soon after.

After monitoring energy performance for a number of years, the building was recognised with a 5 star NABERSNZ rating in 2016, and achieved an additional half star in 2017 using Beca’s own in-house platform (B-Tune) which reduced energy use by a further 20%.

Now a contemporary, future-proofed office building with leading environmental performance, Aorangi House is a shining example of how existing buildings can be revitalised to achieve green building excellence.


Image credit: Studio Pacific Architecture

5.5 Star




64% less

Comparable energy

Aorangi House exterior
Aorangi House exterior

What our team says

What makes the 5.5 star rating so significant is that Aorangi House is a recycled building. It shows sustainable refurbishment is a viable option to the carbon-hungry alternative of demolition and replacement.

Ben Masters – Associate, Building Services

What our client says

Anaro Group is delighted with the 5.5 star rating for such an iconic and mature building. There is growing evidence to support the view that an efficient energy performance improves the value of a building.

Anaro Investment Group

Our People

Alan Barbour

Technical Director - Building Services

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Ben Masters

Senior Associate - Building Services

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Shaan Cory

Associate - Building Science

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