This holiday house was to be a base for its owners to explore the outdoors with their young family. They wanted something minimal, industrial, and inspired by south island high country huts. They wanted good connection to the outdoors, plenty of storage and overflow sleeping space for family and friends, hard-wearing durable finishes, a big mud room for wet and muddy gear and a warm comfortable efficient space. The Hiberna team worked with national Passive House experts eHaus to design and build a simple energy efficient house that was hard wearing but none the less outstanding in its performance and appearance.
One of the main challenges was the wind. Both for the design and on site during construction 155kmh gusts one night in january: Thats a force 2 hurricane. The site is in one of the highest wind zones in NZ and we needed significant extra structure LVL to cope with the high wind load. The design does include some sheltered outside sitting space to the east as the wind comes mostly from the north-west.
We kept the Auckland clients up-to date with an app called Trello. We uploaded photos and gave regular updates so that they could follow the progress of the build from a distance.
One of our favourite features is the mudroom. The corten steel gives industrial, solid feel of it. Ben’s acoustic control (to help reduce echo from hard surfaces) battened ceiling came out beautifully.
The Porcelanosa tiles reflect the texture of the corten.
Energy efficiency was very important to the clients. Twizel has a very extreme climate: Winter overnight lows can sometimes dip below -10C and highs in Summer are often above 30C. The clients approached eHaus because of their expertise and reputation for guaranteed warm and efficient houses built the PassivHaus way.
This home is healthy and comfortable to live in all year round while consuming minimal energy. Even in this extreme climate the only heating is a 5kW ‘Bionic’ wood burner, and even this is hardly used.
We designed the building envelope to have a continuous layer of insulation in this case SIP panels from NZSIP and a fully insulated raft foundation.
The solid timber high performance windows are locally made by Thermadura with triple glazing, they frame the stunning views with the right amount of external shading to protect from overheating in the summer.
The house passed an air tightness test using a blower door to make sure there are no leaks.
We achieved an air change rate of 0.42 ACH – well below the Passive House standard of 0.6
The final key is a heat recovery ventilation system that ensures fresh, dry air 24/7. We used the Passive House Planning Package (energy modelling software) which will ensures that the house will perform.
Many thanks to Alpine Image Company for their beautiful pictures!