For one New Zealand family, ‘forever home’ meant just that when they and their architect chose Nordic Copper for the external skin of their new house on the foreshore of Cass Bay, near Christchurch. The house’s organic design is an exemplar for copper in contemporary architecture while celebrating a strong tradition of craftsmanship.
Having transformed their previous house over 20 years, Aaron Green and his family turned their attention to creating a very personal new home to make the most of a challenging plot with a stunning sea-front location. Close collaboration between the family and their architect, Michael O’Sullivan of Bull O’Sullivan Architecture, characterised the design process. Without a detailed brief, careful consideration of what the whole family wanted from their new home developed a unique design defined by its natural wave-like plan, spatial complexity and organic form.
The main living level is set into the sloping site, before emerging, reaching out towards the sea and elevating to take in expansive panoramic views towards Quail Island. The curvilinear plan – with a fluidity influenced by the architect’s watercolour sketch design methodology – wraps around the plot to maximise accommodation, punctuated by a mullioned, semi-circular stair tower. The building’s organic form generates double-height living areas and distinctive spaces, with extensive timber surfaces adding warmth. Discrete views of the surrounding hills, sky and coastline are curated and perfectly framed with distinctive rooflights and windows.
Natural material choice
Although initially conceived as an entirely cedar-clad building, this material was considered to be too complicated and costly, and alternative solutions were sought. Architect Michael O’Sullivan comprehensively explored with his clients how Nordic Standard copper would naturally change and develop over decades in this specific location, using his trademark watercolour sketches and copper samples – including one from the original roof of Christchurch Town Hall, salvaged following the 2011 earthquake.
Many benefits of copper were identified, including lighter weight requiring less steel structure, durability with no maintenance and a naturally developing surface appearance. As Aaron Green comments: “The copper will become more beautiful with time and an asset that we never have to touch again. It fits in with our aim to create a building that will last for literally hundreds of years.”
Copper is a natural element, one of the first metals used by man and one of our oldest building materials, with a fundamental appeal. Aaron adds: “Copper is something that reminds me a lot of my childhood. I have fond memories of stocking up the fire under our old water boiler – simply known as ‘the copper’ – boiling hand-spun woollen jumpers with green walnut husks to dye them many shades of green and yellow. I also had an old wire-wound crystal set from my great grandfather, which I loved listening to, with a long copper antenna strung out between trees to catch faraway radio transmissions.”
Exemplary detailing and workmanship
Nordic Standard is ideally suited to this dramatic copper carapace emerging out of the seashore, providing a weather-tight external skin that can be adapted to all the building’s geometric complexities. With detailing and installation, again close collaboration was key and copper details were agreed on site between the architect and specialist fabricator/installer The Architectural Roofing Company (TARC).
Nordic Standard 0.7mm-thick ‘mill finish’ copper was used throughout, using a combination of modern long-strip technology and hand-worked traditional details ranging from copper louvres to a rainwater hopper with lipped weir overflow. Elements such as the cave-like entrance, with subtly inclined walls clad inside and out in copper, are a showcase of craftsmanship and testament to TARC’s exceptional care in execution. TARC’s Jordan Ross comments: “This project was a massive challenge but the most satisfying thing that we’ve done.”
Locally-responsive natural patina
Copper’s unique characteristics are defined by a naturally developing patina, which provides impressive protection against corrosion and can repair itself if damaged, giving exceptional durability, sustainability and maintenance-free longevity. Within a few days of exposure to the atmosphere, a copper surface begins to oxidise, changing from the ‘bright’ mill finish to a chestnut brown, which gradually darkens to a chocolate brown.
Over the years, with continued weathering, the distinctive green/blue patina seen on older roofs can eventually result. This is influenced by specific local conditions and particularly likely in exposed locations, with the patina taking on more of a blue hue in marine environments. More information on the evolution of copper surfaces in different environments can be found here.
The Aurubis ‘Nordic Copper’ range provides all these surfaces straight away. The processes involved are generally similar to those taking place over time in the environment, utilising copper mineral compounds, not alien chemical processes.
To explore other inspirational Nordic Copper building studies, visit the website.