Often, yes, even when the fence and the wall would each pass on their own. The fence takes its own height test and the wall takes its own, and a wall that carries a fence has an approval question of its own, because the fence adds height and wind load the wall has to hold. From the neighbour’s side the fence stands on top of the wall, so a low wall and an ordinary fence can add up to more than either rule allows.
What decides it?
The heights come first: the wall’s tallest section, because the height steps along the run, and the fence above it. Then where the wall sits. A wall close to the boundary usually brings assessment and a conversation with the neighbour, and on the boundary itself the dividing fence rules come into it as well. What sits behind the wall matters too. A driveway, a pool or a building above it loads the ground and changes the engineer’s design, and so does the fence.
Then the services under it. A wall over a sewer main needs the asset owner’s consent before it needs the council, on a separate timeline, and the water that drains through the wall has to go somewhere the council accepts.
Who decides?
The certifier, or the council where it assesses building work, decides the wall and the fence on it, and an engineer designs the wall once it passes the height where a design is needed. On the boundary, the neighbours settle the dividing fence between them, while the certifier still decides the wall it stands on.
What goes on the site plan?
The plan shows the wall’s run at its true length with the height of each section, the fence on top with its own height, and the distance from the wall face to the boundary. It marks what sits above the wall and loads it, the existing levels so the cut side and the fill side read correctly, and any sewer main or easement under the run.
Reading it for your own lot
RapidSiteplan reads the lot from its address in a minute: the boundaries, the contours, the house and the mapped services. Trace the wall where it goes and the sheet gives the height of each section, the distance to the boundary and the clearance to the sewer. The retaining walls page shows the sheet, the fencing page covers fence runs and gates, and the council pages for every state show what each council maps. The post on retaining wall heights covers a wall without a fence on top. Start with the address.
Common questions
Do I need approval for a fence on top of a retaining wall? Often. The fence and the wall each take their own height test, and a wall that carries a fence has an approval question of its own, because the fence adds height and load. The certifier reads both heights together from a site plan that shows the wall, the fence and the boundary.
Read next
How high can a fence be without council approval?Where the fence runs decides how high it can go Can I build a retaining wall on the boundary?A retaining wall can often sit on or near the boundary, but its height, footings, drainage and the neighbour’s land decide how Which boundary is the front on a corner block?On a corner block both street boundaries count, and the council’s rules decide which is the frontGeneral information only, not building or legal advice, requirements vary by council and change over time; always confirm with your council or certifier.