Author: Brian March 25, 2023

In Western Australia subdivisions are usually completed with retaining walls in place on the boundary so that all blocks are level.

For the rest of us if we are faced with a sloping site a retaining wall may be needed before you can build…………..but who pays?

Here are a few examples

Block A is sloping down towards the boundary and Block B is fairly flat

Block A has to build up their block and should be the only one to pay. The wall should be within their block.

Block A is fairly flat and Block B Falls away from the Boundary

Block B has to excavate their land and should be the only way to pay. The wall should be within their block.

The slope affect both Blocks A and B

As one block has to be build up and the other has to be excavated both should share the cost. This however can a fairly complex with some of the issues being:

• Should the overall cost be apportioned if one site has to be built up by 1m while the excavation needed is only 0.5m.
• The location of the wall particularly on slopes.
• Fences on the wall
• What happens if you are keen to build but the other block is unsold or the owner is in no rush to build.

Each block having their own wall may be a solution, however these can’t be too close together (See this link for more: Retaining Wall) which may be an issue if you need to site the house near the boundary.

In cases like this you really need to make sure your lawyer sews up a watertight agreement on retaining walls before you buy the block.

This link: Understanding Retaining Walls gives an understanding of the technical issues