Insurance helps, but be aware of potential hazards where your house is situated. Slopes and cliffs erode, floodplains flood, etc. The hazard might not strike every year, but when it does, watch out. If your home is situated in a hazardous area, be sure your insurance policy doesn't specifically exclude damage from it. In CA, we have to buy separate earthquake insurance, and it's not cheap.

I'm not sure if a Land Information Memorandum (LIM) or Property Summary Report would have hazards info, but it could be a place to start. Real estate attorneys may also be able to steer you in the right direction. Try http://www.realenz.co.nz/. I believe it was through that site that I stumbled on some recommendations about hazards info. A geotechnical or civil engineering firm might also be of use. Good luck.