How much does a concrete retaining wall cost per linear foot in New Brunswick?

A poured concrete retaining wall in New Brunswick costs $25–$50 per linear foot per foot of wall height, so a 3-foot-tall wall running 30 linear feet would cost roughly $2,250–$4,500. Concrete block (CMU) walls run $20–$40 per linear foot per foot of height. For walls over 4 feet requiring engineering, expect $40–$75 per linear foot per foot of height, inclusive of engineered drawings.

To make that more concrete: a typical residential retaining wall that holds back a 3-foot grade change and runs 40 feet across a backyard would cost $3,000–$6,000 for a poured concrete or block wall, and $4,800–$9,000 for an engineered wall system if it exceeds the 4-foot permit threshold.

NB building code and permit requirements matter here. Retaining walls with an exposed height greater than 4 feet (1.2 metres) typically require a building permit and engineered drawings in New Brunswick. The engineer's fee alone can add $500–$1,500 to the project cost, but it's not optional — an under-designed retaining wall holds back tonnes of soil plus the hydrostatic pressure of groundwater, and they fail suddenly and completely. The engineering cost is cheap insurance.

Drainage is the critical factor in NB retaining wall longevity. Without adequate drainage behind the wall, hydrostatic water pressure during spring thaw and rainfall events will push any wall — concrete, block, or timber — forward and eventually cause failure. Proper retaining walls include a granular drainage layer behind the wall, weeping tile at the base, and weep holes through the wall face. This drainage layer adds cost but is non-negotiable in NB's climate.

Frost depth is equally important. Retaining wall footings must extend below the 4-foot frost line in most of NB to prevent the footing from heaving in winter. A wall that sits on a frost-susceptible footing will rock forward and back with each winter, loosening its base and eventually tipping. Get quotes from contractors who specify footing depth in writing. New Brunswick Concrete can connect you with retaining wall contractors in your area through the New Brunswick Construction Network.