Member Login

Retaining walls are not dividing fences and are subject to different legislative requirements. When installing retaining walls along boundaries, they must be wholly constructed inside the property – unless you have you consent of the adjoining landowner.

It is a good idea to have the boundary line pegged by a licensed land surveyor to be sure the retaining wall or dividing fence is placed in the correct location.

Retaining walls are only required when a change in level is too much to slope soil between the higher and lower sides, or when site constraints require a level area up to a boundary.

Which neighbour is responsible for installing retaining is sometimes difficult to determine. Often one owner will have lowered their site and the other filled theirs, causing the different heights at the boundary. Talk to your neighbour about how level differences might be resolved. Note that if you are removing the fence to install the retaining wall, you must consult with your neighbour. If you cause damage to the dividing fence, you must ensure it is repaired.

There are a number of suitable materials for the construction of retaining walls, but some are better than others depending on soil type, height of the retaining wall, and if you are on the high or low side.

Limestone retaining walls rely on their mass to provide support. A rule of thumb when considering limestone retaining is that the base of the wall will be at least half of the height and additional backing blocks are required behind the wall. An engineer is required to design a suitable retaining wall as you may need to support a neighbouring driveway or structure, or your own.

Cavity brick retaining walls are do not require backing blocks, but may need a wide footing to provide strength to the wall. The most space efficient choice is concrete panel and post-style retaining walls, however a structural engineer must confirm the suitability and design of retaining walls over 450mm in height, and a building permit is required from the local authority.

16 responses to “Retaining Walls on Boundaries”

  1. Janifer says:

    Before reading your article i was confused about which material should i use for retaining wall but with the help of this article it has been solved out.

  2. christine watson says:

    how high can a retaining wall be if made of the large limestone blocks and not have to have a bigger base than the block itself or backing blocks?

  3. christine watson says:

    what height can a retaining wall be built of the large limestone blocks without having to have a larger base than the block itself or backing blocks?

  4. Stephane says:

    How is the height determined? Is it the full height from the top of the LRW to the bottom (Under normal ground level) or from the Top of LRW to the Ground Level (Higher ground one).

  5. Stephane says:

    Does the require change if you fix a colorbond fence (1.8m) on top of the LRW?

  6. It is probably always best to consult your neighbor no matter what you are doing along the border. You are probably well within your rights to build a new fence or retaining wall on your property, but it is still nice to talk to your neighbor about the change. Good relations with them will go a long way toward making your time in the neighborhood good.

  7. We are on the high side of a property with an old asbestos fence running the width of our block. There is a house on the lower side. The existing fence between the properties is placed approximately 1 Metre WITHIN the boundary, on our property. Can we replace the asbestos fence with a more suitable one, ie along the same line, on our property and not on the pegged boundary. I look forward to your response.
    Thank you & regards.

  8. I think you should determine the landscape before determining what material to use for your retaining wall. You don’t want to use a weaker material and find out years later that you need to replace it. I would be sure and do enough research to make the right decision.

  9. Paul says:

    I would like to replace a panel and post retaining wall and get it closer to the boundary, the current wall is about 800mm from the neighbours fence, but the bottom of the neighbours fence, at his ground level, will be a the top of my retaining.
    If I remove all the sand/soil to where I want the fence 100mm from the fence, how do I support his fence s it does not fall.

  10. Thanks for sharing the information. It is very useful for my future. keep sharing

  11. Barbara Davis says:

    Existing retaining wall on the boundary of my property is clearly built from the natural ground level up and the neighbor property is filling up to create a driveway. This wall must be rebuild now and my neighbor keeps demanding my 50% contribution to the cost of this project. Who can help to establish once for all the ownership of this wall and how much this would cost? Also who should pay for this expertise? I am also concerned that this man is trying to build up this wall by himself, whereas I am not sure what qualifications he has to undertake such a project. The wall is going to be 800 mm tall on the slope with the history of drainage problem and later the fence needs to be erected on the top of this wall. Who can help me to make right decision which would protect me from potential problems later?

Leave a Reply

Your email address will not be published. Required fields are marked *