THE WOW FACTOR
Walls are for climbing in this New Zealand home,
A raw sensibility defines the shapes and mediums of Diagrid House, a cutting-edge design built in stark contrast to a neighbourhood of colonial architecture in Auckland, N.Z.
The 4,100-square-foot residence took over two years to design and build, and is named for its massive roof: a work of concrete created with diagonally intersecting beams — a structure known as a diagrid.
Acting as a podium for the 56tonne roof is the basement garage. Occupying the main floor are the living and dining room, and kitchen-plus-pantry space, as well as four bedrooms and two bathrooms, and a pool, all sit on the main level. A retreat on the second floor includes the parents’ bedroom and another living area.
In addition to the drama of its roof, the Diagrid House’s common living spaces have been designed with secure, cavelike qualities. Hallways and bedrooms were created to be dark and smooth.
Building materials include concrete walls and floors, black zinc metal walls and roofing, cedar boarding, aluminum joinery and raw steel sheet cladding.
Architect Jack McKinney, of Jack McKinney Architects in Auckland, answers a few questions about Diagrid House:
What inspired this home’s unusual design?
This was a house for some friends. We’ve worked on many projects together and they have a building company. This meant we were able to produce something collaborative and sculpturally strong. We were exploring the opportunities of building in concrete. There are no strong precedents for this in New Zealand, so we were looking at great concrete architecture from South America and North America, particularly from the 1950s to the 1970s. Beyond that, we wanted a satisfying “tectonic” massing that had some drama.
Can you explain the roof, and how it’s built?
The main roof is a structural grid of concrete beams, poured on site. This was challenging, due to the slope. Where the veranda is, we have left the lattice of structural beams open. Where there are skylights, we have glazing above. Where it’s solid, we have cementitious sheet linings above the concrete beams — which look like part of the concrete — then a layer of insulation and a layer of profiled zinc metal roofing to keep the rain out. How did you come up with the idea of a climbing wall in the kids’ room?
There’s a great sense of height in these bedrooms, so we introduced small mezzanine spaces right up by the ceiling. The climbing wall is the way to get there. This was something fun for the children. Good architecture can still be playful and fun. How did you modify the site for this home?
The site was originally a fairly steeply sloping hill. We excavated the garage in to form a podium for the rest of the house to sit on. The landscaping is retained/terraced to create a series of levels that rise up the site. What were the building challenges?
We are building in an area with strong controls on the visual appearance of buildings, primarily to protect the 100plus-year-old timber dwellings that predominate the neighbourhood. Getting consent for such a radical design was difficult. Also, structurally this is a complex building. The challenge was making it seem natural and effortless. Explain the garden wall. The pool wall is a large-format porcelain tile — this links to the same material used in the interior bathrooms. The wall at the end of the garden is weathering steel, which rusts on the surface and then is stable. This is used at the rear of the site where the retaining wall is quite high as a design element to transition from the main lawn area to a higher garden area linked to the second floor living area.