One of the first questions homeowners ask us is: "How much does a retaining wall cost?" It's a fair question — and an honest answer requires looking at the factors that drive the price. This guide gives you realistic pricing ranges for Ontario in 2024 so you can budget with confidence.
Retaining Wall Cost by Material (Per Linear Foot)
The biggest cost driver is the wall material. Here are typical installed costs per linear foot for a standard residential wall in Ontario:
- Pressure-treated wood: $100–$200 per linear foot (for a 3–4 foot tall wall)
- Interlocking block (Permacon, Allan Block): $200–$350 per linear foot (for a 3–4 foot tall wall)
- Poured concrete: $300–$500+ per linear foot (for a 4–5 foot wall)
These prices include excavation, base preparation, drainage, materials, and installation. They do not include permits, engineering, or significant site remediation.
How Wall Height Affects Cost
Wall height is a major cost multiplier. A wall that is taller requires:
- More material (obviously)
- Deeper excavation and larger base
- Geogrid reinforcement (for block walls over 4 feet)
- Engineered drawings and permits (typically required over 1 metre / 3.3 feet)
- More drainage infrastructure
As a rough guide, doubling the wall height roughly triples the cost — not doubles — because of the engineering requirements and base work involved.
Other Factors That Affect Cost
- Site access: Walls in difficult-to-access locations (steep slopes, tight side yards, remote areas) cost more due to the extra labour involved.
- Soil conditions: Rocky soil requires more excavation work. Very soft or wet soil may require additional base preparation.
- Drainage requirements: Some sites require more extensive drainage systems, which adds cost but is essential for wall longevity.
- Permits: Building permits for walls over 1 metre typically cost $100–$500+ depending on the municipality.
- Engineering: Walls requiring an engineer's stamp add $1,000–$3,000+ to the project cost.
- Demolition of old wall: If replacing an existing wall, demolition and removal adds cost.
Typical Total Project Costs
- Small garden wall (10 metres, 3 feet tall, wood): $3,000–$6,000
- Standard residential block wall (15 metres, 4 feet tall): $9,000–$18,000
- Larger residential block wall (20 metres, 5 feet tall): $18,000–$35,000
- Concrete wall (15 metres, 5–6 feet tall): $25,000–$50,000+
Is Cheaper Always Worse?
Not necessarily — but be wary of quotes that are significantly lower than the ranges above. A wall built without proper base preparation, inadequate drainage, or below-code construction will fail in 5–10 years, and the cost to remove and replace it will far exceed what you saved upfront.
The best retaining wall is one built correctly the first time with proper drainage engineering. We always provide a detailed written quote so you know exactly what you're getting.
Contact us for a free no-obligation quote on your retaining wall project. We serve London and all of Southwestern Ontario.