Retaining Wall Questions and Answers

The City of Bunbury says building work may need a permit before it starts. Perth councils say a wall of 0.5 m or less is exempt only if every listed condition is met. Ask the City about your wall.

The City of South Perth quotes the Building Regulations 2012 as exempting a wall that retains ground no more than 0.5 m, is not tied to other building work or protection of neighbouring land, and does not trigger certain Building Act sections.

The City of Bunbury says you engage a private building surveyor, who gives a certificate of design compliance. The City has up to 10 business days to assess it.

A City building surveyor assesses it, and the City says it has up to 25 business days. Ask your builder which path they plan to use.

The City of Bunbury lists it as a notice and request for consent to encroach or adversely affect. Ask the builder whether your wall needs it.

The City of South Perth says only with written agreement from the affected neighbours. Ask the council that covers your address, and take advice if a neighbour disagrees.

No. The City of Joondalup and the City of South Perth both say a dividing fence does not qualify to retain soil. A fence sits on the higher ground of a wall on a boundary.

Both councils say the party who changes the lie of the land by cutting or filling is responsible, and that each owner keeps their own wall structurally sound. This is general guidance, not legal advice.

The state register page says builder-work valued over $20,000 needs a registered building service contractor. It does not say whether walls count. Ask each business what applies and check the register.

The Western Australian Government page says to check the name, registration number and licence type. Registered practitioners and contractors can share a number, so match all three.

One national guide says treated timber sleepers, at $250 to $450 per square metre of face, are usually the cheapest for low walls. It says they have a shorter life than concrete sleepers.

The same guide gives $350 to $650 per square metre of wall face for concrete sleepers with steel posts, installed and including GST. Ask for a Bunbury quote, since local prices differ.

The guide says soil pressure climbs fast with height, so a 2 m wall needs far more than twice the structure of a 1 m wall. It also adds engineering and approval costs.

It should be, but ask. The guide says drainage is a real line item and skipping it is the most common reason cheap walls fail. Ask what pipe, gravel and weep holes are quoted.

The Bureau of Meteorology station at Bunbury averages 737.3 mm a year, with a wettest year of 995.6 in 1999 and a driest of 484.4 in 2010.

The same station recorded 92.0 mm on 4 July 1999 and averages 5.2 days a year with 25 mm or more. Ask the builder how drainage handles a very wet day.

The station averages 11.1 days a year at or above 35 degrees, and its highest reading is 40.8 degrees on 11 January 2014.

Not entirely. The guide's publisher sells quoting software to tradies, so treat its figures as a cross-check, not a promise.

Our guides include Australind, Eaton, Dalyellup and Gelorup, which Wikipedia places in other shires. The council rules there may differ from the City's.

No. We pass your request to independent local businesses, and each decides whether to quote. We cannot promise one will be available in your suburb.