Construction work on new buildings or renovation to existing structures requires planning approval from the relevant city council before any work can begin, this is according to the National Building Regulations (NBR). However there are some renovations you can do without planning approval.
Adding small structures
You do not need approval for small outdoor structures however you will still need permission. Most municipalities have a form for minor building work that you can fill out and submit. Some examples of small outdoor structures bellow.
Tool shed - must be under 10m2
Children's playhouse - must be under 5m2
Greenhouse - must be under 15m2
Solid fuel store - must be under 10m2 and not higher than 2m
Chicken coup - must be under 10m2
Swimming pool change room - must be under 10m2
Speak to your local authority about the type of structure you want to build and whether you need plans.
Changing internal features
Internal walls can be knocked down to create an open plan layout, without planning approval. However you have to be certain that the wall you intend to knock down is not a load bearing wall, if you are uncertain check in with your local authority or a structural engineer as this can affect the structural safety of the building.
Updating windows and doors
Home owners are also free to update their windows and doors as long as the size and shape of the openings are not altered, unless you have approval.