How Much Does It Cost To Install A Retaining Wall?

Why install retaining walls?

Think of a retaining wall as the landscaping version of a condo building – you can do much more with the same footprint if you build in layers than if you only use the ground level.

With a wide range of styles and finishing options available, you can personalize your retaining wall to suit the character and vibe of your property, whether that’s modern and slick or low-key and natural. 

In addition to making your space more practical, retaining walls serve another functional purpose – ensuring that your land stays stable over time. This helps the area resist erosion and loss of material that could potentially impact the structures on your property, like your home or patio.

Retaining wall cost per square foot

Retaining wall costs are quoted per square foot. More minor expenses included in the overall price include materials and labor. Generally, you can expect to pay $23.20 to $31.77 per square foot — but complex projects could cost more. 

Take a look at this handy table for the average retaining wall installation costs per square foot:

Costs for retaining wall materials

When estimating the total cost for your retaining wall installation, it’s essential to consider the materials you want because they’ll account for about half of the total cost. Specific sizes of retaining walls will require more robust materials, so while the visual appeal is essential, it’s not the only factor that will impact your cost. Below, we’ll walk through the most common materials so you can understand the average prices. 

Cinder block

Cinder block is the most cost-effective option for shorter retaining walls, averaging $10 to $12 per square foot for material. Cinder blocks can be painted to provide a more attractive finish, so don’t be deterred if you think you’ll be stuck with a dull gray wall. 

Interlocking concrete block

Interlocking concrete blocks are poured and reinforced to create retaining walls, and as long as they’re installed correctly, these sturdy blocks will last for decades. Rebar loops and hooks are cast into the blocks to add even more hardwearing durability. You’ll find interlocking concrete block walls for $20 to $30 per square foot.

Wood timbers

Wood timbers blend perfectly with a more natural design, and if they’re treated before installation, they can weather well and last for many years before needing to be replaced. 

Wood timbers can hold a surprising amount of weight and volume; depending on your location, lumber pricing costs between $15 and $25 per square foot.

Poured concrete

Poured concrete differs from concrete blocks in that it’s formed and poured on-site rather than pre-cast and delivered in blocks. 

Poured concrete takes more labor hours and specialized skills, making it the most expensive option. You can expect to pay between $30 and $40 per square foot for this, but it’s also excellent for durability and strength, so it’s worthwhile to consider for intricate or large spaces.

Aggregate and Gabion

Aggregate and gabion are similar options, and both involve using stones to create a solid and durable retaining wall.

Aggregate uses smaller gravel combined with soil and compacted, creating a compressed retaining wall that blends well with a natural environment.

Gabion is similar but uses larger stones within a metal mesh to create the proper size and shape. Both aggregate and gabion cost between $20 to $25 per square foot.

Retaining wall installation cost factors

While materials factor heavily into the cost of your retaining wall installation, there are a few other vital factors to consider so that you’re not surprised when you get quotes. 

How deep the foundation needs to be and the type of material that needs to be excavated are important factors. Dense clay will take more time and cost more than peaty, light soil, and likely need backfill to create optimal drainage. 

The available access to your build site is also something to consider. Excavating machinery is heavy and requires large areas to access and maneuver inside. Costs mount up quickly if your machine operators need to create access roads and temporary bridges.

Once the costs are considered, it’s time to consider your design and finishing options. Creating more intricate designs with curves, steps, and decorative options will increase costs, as you may need to pay a designer on top of the extra labor time. 

Retaining wall repair cost

• Poor Drainage – If poor drainage means the soil becomes saturated with water, the material behind the wall will need excavating and replacing with a gravel backfill. This work typically costs around $70 per linear foot.
• Cracks and crumbling – Cracks and crumbling in concrete walls can be fixed with simple patching, so long as the problem isn't structural. Expect to pay between $150 and $300 per crack for a surface touch-up.
• Bowing – Bowing or leaning walls usually require new tiebacks fitted to anchor the wall at the cost of $200 to $300 each.
• Wall foundation problems – Problems with the wall's foundations may require a complete demolition and rebuild at $30-$70 per square foot, but less severe cases can be fixed by adding tiebacks at $200-$300 each.
• Tiebacks – Tiebacks can also be used to fix walls that are shifting at the top, again at the cost of $200-$300 per piece.

DIY retaining wall installation vs hiring a professional

Small retaining wall installations are relatively simple for an experienced DIY-er to tackle, but for the most part, this type of project is best left to the pros for a few compelling reasons.

• Retaining walls over four feet need a structural engineer to approve plans.
• Constructing a retaining wall that will stand the test of time requires a lot of different considerations, and the potential risks if your wall fails can be high.
• Excavation and backfilling are time-consuming and labor-intensive if you don’t have a machine operator to help you. Think days and days of backbreaking shoveling versus an hour or two with a machine. 

If you have relevant construction experience, taking on the installation of a retaining wall on your property could be the right move. For people who are short on time or don’t feel like taking on a large project, consider calling in the pros to take care of most, if not all, of your retaining wall.