This was one of the most challenging sites I have worked on!
It is a very windy site. The building code sets out design parameters for wind speeds up to 50 metres per second (180 kmper hour). Anything over that needs to be specifically designed. This site had a design wind speed of close to 70 meters per second – that almost 250 km/h! The power of wind rises exponentially with speed it is not a linear relationship – so there are pretty strong gusts of wind on the cliff top above Barrett Reef (The Wahine ferry sank at Barrett Reef).
This makes it complicated to manage water ingress into the building fabric, because you have to with wind blown rain driving up the cliff face coming from below the eaves. The steel frames also need to designed carefully to ensure they are robust enough to minimise movement and prevent cracking yet not obscure the fabulous view.
As if all that wasn’t complicated enough, the ground conditions were far from ideal. The site had a lot of fill and this meant that the foundations were going to be expensive to build.
I should have run in the opposite direction, but the clients were fantastic people and I love challenging projects.
I started the design process by meeting the geotech engineer Richard Skilton on site with a digger driver I knew and we drilled sample holes around the site to figure out the most economical way to deal with the foundation design. I also spent a lot of time working with my good friend Anil Krishnan of MSC Engineers in Auckland on the optimal steel structural bracing.
We got there in the end… and the clients love the place.
The house was built by Aaron Boddington and Joe Todd of Boddington Todd.