I have just started the design of two-story duplex, each 80msq, in Wellington. While seeking to maximise our long-term rental return, I want to build houses that tenants will want to stay in. I will be using SIP floors (parking and storage under one unit), (external) walls and roof. I am now researching windows and would appreciate advice about the best "thermally efficient" value for money solutions. The site is sunny, north facing, gently sloped and, for Wellington, only a high wind zone.
Starting site plan at https://drive.google.com/open?id=0B1SdA-vKLONwVjVDdVZQVEdSY0MxS1RfQ2MydjVzdjByVnNn. We also own the other three houses partially shown on the drawing, one being the original house and the other two steel SIPs from Quick Build Homes.
All advice appreciated and I am happy to chase up leads and readings.