Natural Ventilation

The Ironbank building is a naturally ventilated building which provides 100% fresh air to occupants, as compared with the average of 25% for air conditioned buildings in New Zealand.

To eliminate the use of ozone depleting or potentially global warming refrigerants used in commercial air conditioning, Ironbank is designed to facilitate good natural ventilation during summer and winter seasons, this is achieved with the following features:

High levels of thermal insulation allow the building to retain winter heat and block the summer heat.

Use of exposed concrete surfaces within the tenancies absorbs and slowly releases heat to help maintain stable internal temperatures.

Windows for night time flush ventilation during the summer months to refresh the tenancy spaces and reduce peak daytime temperatures within.

Design of large overhangs to the Northern facades to minimise direct solar heat gain and glare into the workspace.

Each tenancy is provided with local controls to enable each tenancy occupant to adjust internal conditions to meet individual needs. The range of ventilation options range from low/high level cross ventilation using locally controlled automated windows to large cross flow ventilation using the sliding doors and vertically hinged windows on the North and South facades. This enables a full range of options for the tenant to tailor the internal environment to their own needs.


In Spring you will notice the days becoming warmer but the temperatures still drop in the evening. Remember to dress for the season! At this time of year we can have 4 seasons in a day so layers are good, especially merino type underlayers.

If you open the windows during the day, remember to close them at night before you leave to trap the warmth inside the building.


During the Summer months in a naturally controlled building such as Ironbank we ask again that you dress appropriately for the season. We ask that you open your windows to ensure good air movement across the tenancies on warm days. There are various combinations available to you to enable localised air movement (vertical casement windows on North and South) or larger cross flow ventilation (East & West windows and sliding windows on North and South). At night you are able to leave your East/West windows open as they are secure and unable to be accessed from outside. By leaving these open a small amount through the night the internal space is refreshed and your peak internal temperatures during the day will be reduced by the coolness stored in the concrete.


In Autumn you will notice the days become cooler but we may still have some hot sunny days. The temperatures will however start to drop in the late afternoon. It’s time to adjust your dressing for this variable time of year and we recommend you add a layer or two in case the temperatures swing over the course of a day.

If you open the windows during the day, remember to close them at night before you leave to trap the warmth inside the building.


At this time of the year the building facade should be shut down to keep as much warmth in the building as possible. Should we get a sunny day you are still able to open your windows, just remember to close them again before you leave for the day!

The internal temperatures will fluctuate and the mornings may be chilly as it is a natural ‘free running’ building so to minimise the artificial heating required and maximise comfort we recommend thermal underlayers and jumpers (jerseys!). Also we have found that keeping your feet warm affects your overall feeling of comfort so warm socks and perhaps a winter mat under your desk will help. If any of your staff have a particular issue with cold feet (we are all different!) then we can recommend some small under desk heaters.

Heater Use

To take the edge off very cold winter days use the low carbon emitting electric heaters mounted to the ceiling. To turn these on push the on button and the blue light will show, also make sure that the switch above the button is turned to on. Once activated the heaters will run for 2 hours and then automatically switch off, you will need to push the button again throught the day to achieve another 2 hours of heating. 

Last modified: 18 Jul, 2019