Retaining Wall Costs in the Pacific Northwest

Retaining walls are more than an interesting accent in your yard. Well-built retaining walls play a significant role in protecting your property, draining water away from your house, and helping you effectively manage and reuse the Pacific Northwest’s ample rainfall.

Small retaining walls are a relatively simple project you may be able to install on your own. But when you consider the time and effort it takes to ensure your retaining walls are properly installed and perform as intended, you may decide to leave it to the pros.

Whether you do it yourself or hire someone to install your retaining walls, the cost is, of course, a significant consideration. When you dig into estimating the final price of your retaining walls, you’ll find it’s calculated using a lot of tiny details.

What’s the Average Retaining Wall Installation Cost?

You can expect to pay anywhere from $3,500 to $13,700 for a retaining wall installation, but the national average is $6,300.

A quick way to estimate what you’ll pay is to determine the price of a retaining wall per square foot.

The average per-square-foot price to build one is $33, though you can expect to pay anywhere from $20 to $53 per square foot. So, the longer or taller the retaining wall, the more you’ll pay.

Average Retaining Wall Cost by Length

Length (in linear feet) Average Cost
10 feet $1,200
15 feet $1,800
20 feet $2,400
25 feet $3,000
30 feet $3,600
35 feet $4,200
40 feet $4,800
45 feet $5,400
50 feet $5,000
55 feet $6,600
60 feet $7,200

It’s also important to note that the shape of the retaining wall will impact cost. A retaining wall with curves or a serpentine shape will cost more than one with straight lines.

Factors That Impact Retaining Wall Cost

While the per-square-foot cost is a rough estimate, there are many other factors that impact the final price of your retaining walls.

Material Type

The material you use to build the retaining walls is one of the largest impacts on cost. Something like wood is relatively inexpensive compared to something like concrete or steel retaining walls. Of course, another way to measure the cost is how long the material lasts. Wood is a natural element that breaks down over time. And though something like natural stone also wears down, it doesn’t erode nearly as quickly as wood.

Retaining Wall Cost by Material

Material Details Average Cost per Square Foot
Vinyl Retaining Wall Lightweight and compact. Good for retaining walls that aren’t holding a lot of weight. $10 – $15
Gabion Retaining Wall Rock filled wire boxes. They don’t require a foundation and are easy to install. $10 – $40
Wood Retaining Wall Low-cost and easier to install than other retaining walls. But they degrade over time and need waterproofing. $13 – $35
Brick Retaining Wall Comes in several colors and are often used as a decorative cover for poured concrete retaining walls. $17 – $43
Rammed Earth Retaining Wall A mix of compacted soil with a binder (like cement). Similar in strength to concrete but more eco-friendly. $20 – $30
Poured Concrete Retaining Wall Very durable and long-lasting. $20 – $40
Natural Stone Retaining Wall A durable solution with many design options. Not always easy to get exactly what you want. $20 – $90
I-Beam Retaining Wall Used to support large or heavy structures, like patios or pools. $35 – $120
Steel Retaining Wall The most supportive and durable retaining wall material. $15 – $150

*Note: Railroad ties are often mentioned as a retaining wall material. While it is a way to reuse and recycle, railroad ties are usually coated in toxic substances and are not recommended for new retaining walls.

Location

Where you’re building retaining walls also impacts on cost. Building a small or even medium-sized retaining wall that makes your backyard look interesting doesn’t require a lot of structural support. But if your retaining wall is more functional and holds back significant amounts of soil, it likely needs additional structural support, which will increase the final price.

Retaining Wall Costs by Location (per Square Foot)

Front Yard $30 – $200
Driveway $35 – $130
Backyard $40 – $465
Slope $40 – $200
Swimming Pool $1,000 – $3,000
Garden $30 – $130

Add Ons

Adding a retaining wall is a significant project. So, you may decide to make the most of the construction and add additional items to complete your backyard design. While it can save you money in the long run (no need to pay for permits again, can get it all done at once), add-ons can raise your overall retaining wall project costs. 

Estimated Cost of Retaining Wall Add-Ons

Patio $1,500 – $5,500
Flower Beds $1,000 – $1,300
Lighting $2,000 – $5,810
Outdoor Kitchen $6,035 – $14,835
Deck $3,600 – $20,000

Additional Cost Impacts

Even if you don’t add any extras, there are additional costs to be aware of. Some are mandatory (like permits), while others may be necessary because of the specifics of your property and the type of retaining wall you’re installing.

Additional Costs

Item Details Cost
Permits Most locales require a permit if your retaining wall is taller than three or four feet $40 – $450 
Grading and Leveling May be necessary to create a level surface that drains properly $0.40 – $2.00 per square foot
Excavating Required if you need to remove dirt or an old retaining wall $50 – $200 per cubic yard
Clearing You may need to remove trees, bushes, or other plants to have the proper work site $735 – $2,330
Waterproofing Wood and some natural materials require waterproofing to ensure they last $2.00 – $10.00 per square foot
Reinforcements Lighter materials may need steel reinforcements to hold the weight $1.50 – $2.50 per square foot
Labor Labor is usually an extra charge $15 – $40 per square foot (or $50 – to $75 per hour)
Drainage You may need to install an additional drainage system to prevent water damage or flooding $15 – $30 per foot
Soil and Structural Engineer Analysis A professional site analysis may be required to ensure you can build the retaining wall safely $80 – $120 per hour
Survey Some locales require a site survey to make sure you stay clear of utilities and property lines $200 – $1,200
Backfill You may need additional dirt to finish your retaining wall project $15 – $50 per yard

Your Retaining Wall Pros

Adding retaining walls to your landscape design project can be a significant undertaking. From placing your retaining walls in the right location to ensuring they’re functional and last a long time, this kind of project is not for the faint of heart.

The professionals at Dig’Um Dirtworks are your retaining wall pros. Whether you want retaining walls made of concrete blocks, a small retaining wall, or something else, we can help. Schedule your free consultation today and learn how we can help you design the beautiful, functional yard of your dreams.