LandscapersUpdated March 2026 · 2 min read

How to Quote a Retaining Wall in Australia

Guide to quoting retaining wall construction. Covers timber, concrete sleeper, and block retaining walls with material calculations, drainage, and engineering costs.

What to Include in a Retaining Wall Quote

A retaining wall quote should cover: excavation, posts or footings, wall material (sleepers, blocks, or stone), drainage (ag pipe, gravel, geofabric), backfill, engineering (if over 600mm), and site clean-up. Always specify the wall type, height, and length. Include a diagram or photo reference if possible.

Retaining Wall Costs by Type

Timber sleeper wall: $200–$400/linear metre. Concrete sleeper wall: $300–$600/linear metre. Besser block wall (rendered): $350–$550/linear metre. Natural stone: $400–$800/linear metre. Costs increase significantly with height — a 1.5m wall costs roughly double a 600mm wall per linear metre due to posts, engineering, and drainage.

Engineering Requirements

In most Australian states, retaining walls over 600mm high require engineering certification. Walls over 1m may also need council approval. Engineering fees: $500–$2,000 depending on complexity. Always check before quoting. Include engineering costs as a line item and note that the design may affect material quantities.

Drainage Is Critical

Every retaining wall needs proper drainage. Include: 100mm ag pipe at the base wrapped in geofabric, 200–300mm of 20mm drainage gravel behind the wall, geofabric between gravel and soil, and weep holes or drainage outlets at the base. Poor drainage is the number one cause of retaining wall failure. Always include full drainage in your quote.

Quoting Tips

1. Visit the site to check soil type and access. 2. Check for underground services before quoting. 3. Include engineering for walls over 600mm. 4. Always include proper drainage — cutting corners here leads to wall failure. 5. Account for spoil removal if excavation is required.