The other week, Cr Fliss Butcher suggested that there should be a ban on south-facing homes in Dunedin. Predictably (as can be seen in the comments thread in the link), this has been met with a hail of derision, but also some support. Personally, I think New Zealand building standards seem to be always out of date. Houses that were built as little as 10 years ago seem embarrassingly bad by current standards because of this. It was only in 2008 that double glazing became sort of mandatory, and many houses from the 90s (and some even up until 2008) have embarrassingly little insulation.
There are already rules on south, east and west facing glazing; if a house has more than 30% of its glazing on these walls, thermal modelling is required. This seems a more nuanced approach than simply banning south-facing homes. However, as always it seems that the rules could be more aggressive. I think that if you can afford to build a new house, then you can afford to spend a little more money to make sure that you are building a real asset. In essence, if you are going to build a new house in Dunedin, you may as well build a bloody warm one.
Research in Dunedin by economist Dr Paul Thorsnes backs this up. Houses built after 1978 (when insulation first became compulsory), command a hefty price premium relative to pre-insulation era houses. Similarly, houses that receive more sun in mid-winter are worth more than houses that receive less sun. This effect is particularly profound for pre-insulation era houses; a 3.9% increase for each additional hour of mid-winter sun. Perhaps unsurprisingly, Thorsnes lives in a sun-trap property.
But this is also a tale of how far we have come. When Austrian refugee architect Ernst Plischke designed a house in Christchurch c.1940, it was initially rejected because it did not have any* south facing windows. The issue was, of course, that the street was to the south, and under the rules of the time, the house had to address the street. The solution was eventually to add a few windows.
Fast forward 50-60 years, and the idea of an L-shaped house, opening to the sun and an outdoor living space is now taken as an almost given. The design seems surprisingly contemporary, as do some of Plischke’s other designs, such as the house he designed for Bill Sutch in Wellington, below.
*I’m pretty sure the design actually had none, and that he added some small windows, but I’m having to rely on my memory of this exhibition: ERNST PLISCHKE – ARCHITECT, City Gallery, Wellington, 5 September-28 November 2004.