Yes, in most cases you can install a new internal door yourself in New Zealand. Fitting a standard internal door is not restricted work under the Building Act, and it typically doesn't require a building consent — but there are a few important things to understand before you pick up your chisel.
Does Installing an Internal Door Need a Building Consent?
For a straightforward like-for-like replacement of an existing internal door, or fitting a door into an already-framed opening, you generally won't need a building consent. This falls under Schedule 1 of the Building Act 2004, which lists exemptions for minor building work.
However, if you're creating a new opening in a wall — especially a load-bearing wall — the situation changes significantly. Cutting into a structural wall may require a building consent and must comply with NZS 3604 (Timber-framed buildings). Always check with your local council before modifying any wall structure. When in doubt, consult a Licensed Building Practitioner (LBP).
What Tools and Materials Will You Need?
Before you start, gather the following:
- Tape measure, pencil, and spirit level
- Circular saw or hand saw (for trimming the door to size)
- Plane (for fine-fitting edges)
- Chisel and mallet (for hinge and latch recesses)
- Power drill and bits
- Door jamb/lining set (if replacing the frame as well)
- Hinges (typically 3 × 75 mm or 100 mm butt hinges for a standard door)
- Door latch or handle set
- Packing shims and nails or screws
You'll find a good range of door hardware and pre-hung door sets at Bunnings, Mitre 10, and PlaceMakers.
Step-by-Step Overview
1. Measure the Opening Carefully
Measure the rough opening (the framed gap in the wall) and compare it to your door's dimensions. Standard NZ internal doors are commonly 1980 mm tall × 760 mm, 810 mm, or 860 mm wide, and 35 mm thick — but always measure your specific opening.
2. Prepare the Door Lining
If you're replacing the frame as well, fit the door lining (jamb) first. Check it's plumb and square using your spirit level. Use packing shims to adjust as needed before nailing or screwing it into place.
3. Trim the Door to Size
Allow a 2–3 mm clearance gap on each side and at the top, and around 10–12 mm at the bottom (more if you have thick carpet). Trim carefully with a saw, then plane the edges smooth.
4. Mark and Chisel Hinge Recesses
Position hinges 150 mm from the top and 225 mm from the bottom of the door (a third hinge in the middle is recommended for heavier doors). Mark the hinge positions on both the door and the jamb, then chisel out shallow recesses so the hinges sit flush.
5. Hang the Door
Fit the hinges to the door first, then hold the door in the opening and screw the hinges to the jamb. Check the door swings freely and closes without binding.
6. Fit the Latch and Handle
Mark and drill the latch hole through the door edge and the handle spindle hole through the face. Chisel a recess for the latch faceplate, fit the latch, then attach the handles. Mark and chisel the strike plate recess in the jamb.
7. Finishing
Once the door operates smoothly, fill any gaps in the lining with stopping compound, sand back, and paint or stain to match. Resene and Dulux both offer suitable interior trim paints.
Fire Doors and Smoke Separation
If the door is between a garage and the living area, or in a multi-unit dwelling, it may need to be a fire-rated door to comply with NZ Building Code Clause C. Fire doors must be installed correctly and must not be modified. Check with your council or an LBP if you're unsure whether your door location has fire-separation requirements.
Healthy Homes and Rental Properties
If you're a landlord, note that internal doors can affect draught-stopping compliance under the Healthy Homes Standards. Ensure any new door seals the room adequately.
When to Call a Professional
Consider hiring a qualified carpenter if:
- You need to create or enlarge an opening in a wall, particularly a load-bearing one
- The door location has fire-rating requirements
- You're not confident with the tools or the door isn't hanging correctly after your attempts
- The existing frame is out of square or damaged and needs significant remediation
A skilled carpenter can typically hang an internal door in a few hours. You can find experienced local carpenters on tradedirectory.co.nz.