Who is responsible for repair costs relating to retaining walls between my villa and common property? Greg, NSW

If it’s part of common property under a strata scheme, your strata committee would be responsible for maintaining this. It depends on where the wall is located between your unit and the common property. It could be a 50-50 responsibility between yourself as the property owner and the owners corporation.

You could raise your concern with them for an in-depth investigation to assess who is responsible for its maintenance and repair.

Here is an article which could be an interesting read.