NSW Retaining wall built on top of the fill, and then more fill

Hi all,

I have a slight dispute with my neighbour regarding their retaining wall on our property boundary. But let me tell some background details first.

I bought a block of land a few years ago, and once land was released, we had a survey on the land, including a contour survey. Our block is on the low side of a slope, i.e. our next door neighbour's house sits almost one meter higher than ours. We had plenty of delays with our build, so neighbour built their house before us. When their builder was tidying up the perimeter of their house, they spread soil around the house slab, and created a slope towards my property, bringing 20-40 cm deep fill on the boundary. Then they built a retaining wall on top of that fill, and added more fill around the house to create a level surface on their side.

Now that my house was finally built, my builder had to remove the fill on my side that was spread on the property boundary, because my house was designed using the contours from survey as a reference. Obviously, it looks like they have cut into the ground, and there is exposed soil underneath the neighbour's retaining wall that now needs additional retaining, just as the posts needs to be extended as well.

I have checked current ground levels in the areas in question using our house slab levels from plan as reference, and my calculations show that ground levels are still above what they are in the survey. In other words, what appears to be our cut is in reality still neighbour's fill.

Now the question is, who is responsible for the job modifying the retaining wall. My opinion is that it would be neighbour's responsibility, because the fill in question is solely part of their landscaping. I also view that the original contour survey is the reference that any changes in ground levels are measured against, and there is no cut.

Neighbour, on the other hand, thinks that it would be my responsibility, because my builder has 'excavated below the natural fall of the land'. She also seems to have some professional support for that opinion. Since that view is different to mine, I assume that there can be two explanations. Firstly, professionals only look at the appearance, disregarding the real changes to natural levels. Secondly, there is this possibility that now the reference is no longer the original survey, but the levels that the neighbour's builder created, and that actually seems to be the way many people think.

If the second option would be correct, it creates an interesting legal, or at least moral scenario. Namely, you would be allowed to dump unauthorised soil on your neighbour's land in the name of landscaping yours, get away with retaining your fill, since it is supported by the part on your neighbour's land, and finally when your neighbour has to remove the soil you dumped, they will be liable for building a retaining wall for you. Sounds weird, but that's basically what we have at hand at the moment.

I would appreciate if someone wiser could shed some light into this dilemma.

Thank you,

Tim Kay

As far as I know, there was no approval regarding ground levels. On the other hand, no council would allow altering the ground levels on neighbouring properties without landowner's consent, so there is now way there is compliance in this case.

Retaining wall is a post and sleeper -type timber construction. Now it needs another course or two of sleepers underneath, and also new posts that go deeper into the ground.

Is there any other, say, less drastic way than taking people to court to turn their heads and get them do the right thing?

Tim Kay

Now after digging into this, I found some confusing definitions that may explain why there are differing views to this. I thought that the levels from the initial survey would be the reference to use, but there seem to be term "existing ground level" as well, whatever that means. Could "existing" mean that now my boundary - with the unauthorized fill - would be the reference after all? I guess that is the logic in neighbour's position.

Tim Kay

I was googling "natural ground level definition nsw" and there was some documents where different terms popped up. The thing is that in my case it is vital to understand what law says about reference levels, and I haven't got a conclusive answer yet, so I have been looking elsewhere as well.

Tim Kay