Case Study: The Dunlop Hub

Wanaka is home to the first certified Passive House office building in New Zealand – one of just five worldwide.

The Dunlop Builders Hub is a beautiful blend of sustainable design and elegant architecture,  and the office space has achieved Passive House Plus certification.

The certification signifies that the building not only meets the strict energy efficiency standards of Passive House certification but also generates a portion of its energy onsite from renewable sources.

That’s where Wanaka Solar came in. We worked with Dunlop Builders to design a solar system that would work with the other passive build elements.  

In passive building projects, teamwork and careful timing are crucial. For example, we remained flexible and kept in regular contact to ensure our cables were run before the building was made airtight.

At the request of the Dunlop Hub team after running the system for about a month, we compared different energy retailer offers based on the building’s actual energy production and consumption. We found they were best suited to Ecotricity, a certified climate-positive option that aligned perfectly with the building’s values.

24 Hyundai 400W panels

8.2kW Fronius inverter

Ohm Pilot hot water control

The estimated system performance is 10,859 kWh per year.

From March to mid-June, the office generated 2440 kWh and consumed 1900 kWh, taking into account workshop usage as well.

During the passive house planning process, the heating demand was estimated to be 14 kWh/m² or 2058 kWh annually. Considering other energy demands, the total expected energy usage is 9114 kWh. With an anticipated generation of 10,859 kWh, the building is set to achieve a net gain of 1714 kWh.