Park Lane. Humphrey Hall.

Not Christchurch, but close enough: Humphrey Hall must have frightened the locals in Timaru when he designed this house in 1938. Just back from working in London, he was clearly influenced by the International Modernist style that was kicking around Europe at the time. Most radical was the open rooftop sundeck that has been filled in since it was discovered the sun, like most good things, causes cancer.
Thanks to Michael for the shots.