These guys are awesome. Tell them what you want to do and they will let you know exactly what you need.
They cut your wood to size for you. They have off cuts of certain woods so you dont have to pay for the full length. They build fence sections, outdoor tables and chairs and birdhouses for you too!! They order in parts or wood for you. They offer a free courtesy trailer and their prices are very sharp!
For your building needs seriously try these guys first.
36 Main Rd Tawa Wellington 5028
Building Services Contractors NZ Inc (BSCNZ)
Timber Industry Federation Inc (NZ)