Aorangi House

Wellington, New Zealand

Aorangi House

Key Facts

5* Greenstar Office Design Rating and a 5* NABERSNZ Base Building Rating

  • First refurbished office building in New Zealand to achieve this


  • Tenancy Rating

50% better base building energy performance

  • than average New Zealand office building

46 year old

  • refurbished office building

The IES Virtual Environment (IESVE or the VE) was used as a design tool for the renovation of the 46 year old Aorangi House in Wellington, New Zealand, with the purpose to achieve a 5* Greenstar Office Design rating, good indoor environmental quality, and maximise the operation in a natural ventilation mode. The project has also recently achieved a 5* NABERSNZ Base Building Rating, demonstrating 50% better base building energy performance than the average New Zealand office building.

IES technology helped integrate energy smart features into the building design to improve the overall performance of the property. Beca used the VE to assess natural ventilation performance and thermal comfort, passive solar design strategies, daylight availability and greenstar credit points.

The passive solar design strategy involved using the buildings existing concrete structure to improve natural ventilation performance. IESVE technology was used to assess the improved natural ventilation performance through the placement of wall insulation external to the concrete structure in conjunction with an automated night flushing ventilation strategy. The result was that the natural ventilation mode was benchmarked to operate a lot more effectively, reducing peak summer temperatures.

The VE was also used to examine different configurations of solar shading with the aim to find a balance between reducing solar gain in summer while maximising passive solar gains in winter and providing good daylight availability which was assessed through the use of Radiance simulations. The VE was also used to run in natural ventilation mode to determine what extent of solar shading was required to achieve natural ventilation design performance targets.

Throughout the design of the refurbishment, the VE informed the best balance of elements and the effect that any changes to the facade would have to indoor environmental quality and the passive solar design strategy. It permitted those involved in the project to decide on the best solution based on the quantitative results the VE provided as opposed to a best guess.

The building achieved a 5* NABERSNZ Base Building energy rating, it is the first refurbished office building in New Zealand to do so. Beca, the main tenant in the building, also achieved a 4.5 star NABERSNZ tenancy rating.