Retaining Wall Cost and Material Options
Block, timber, boulder, and poured concrete walls compared by cost and lifespan.
Retaining walls range from $20/sq ft for treated timber to $80/sq ft for poured concrete or natural stone. Beyond 4 feet tall, most jurisdictions require engineered drawings and a permit — and the cost roughly doubles.
Material cost by type
Segmental concrete block (Allan Block, Versa-Lok): $25-$45/sq ft installed. Most common choice. 40+ year lifespan with proper drainage.
Pressure-treated timber: $18-$30/sq ft. Cheapest option but only 15-20 years before rot starts. Avoid for permanent installations.
Boulder/fieldstone: $35-$70/sq ft. Aesthetic premium, no mortar required for shorter walls.
Poured concrete: $50-$90/sq ft. Strongest, requires forms and engineering for any meaningful height.
Drainage is what makes them last
Every retaining wall taller than 18" needs perforated drain pipe at the base, gravel backfill, and weep holes or geotextile fabric. Walls that fail almost always failed because of hydrostatic pressure from missing drainage.
If your contractor's quote doesn't itemize drainage, get a different quote.