In Palmerston North, you may need smoke alarms in your house if you're putting a swimming pool in the garden.
In Christchurch you must put your wheelie rubbish bins a minimum of 50cm apart.
In Manukau you need a building consent if you move a toilet to the opposite corner of the bathroom.
In Invercargill you need a building consent to change tap positions in a sink.
Putting in an above-ground swimming pool in Waitakere requires a building consent, plus a $1000 deposit in case a builder's truck damages the road.
My own favourite:
In Waimakariri district you can't build within 250m of another property if the other owner spreads pig effluent on their lawn.