I recently spoke with someone who was looking for a retaining wall, four feet tall and ninety feet long. Before moving forward with a consultation he wanted a sense of what such a wall would cost.
He was surprised, to say the least.
There are a lot of design consideration for retaining walls in northern Virginia, and every site is different. Slope, soils, access, permits, and existing conditions impact the costs, so it’s not generally practical to create a proposal for a retaining wall based solely on square foot pricing. The best contractors examine the site, create a landscape plan (or have a landscape designer create a plan), work out all the materials needed down to the number of tubes of adhesive, and base the price on the labor and materials required to build that individual wall.
That said, I will use square foot numbers to at least start the conversation so I can help the client decide if they’re ready to move forward with the design. When we multiply the length of the wall by the height we get the total square feet of face, or SFF. Here’s how different materials can break down by SFF. Keep in mind that these are not absolutes, just starting points. Your site conditions may result in higher or lower costs.
Pressure-treated 6×6 retaining wall: Generally, a wall of this type will start at $35-45/ SFF. So in the example conversation with the homeowner who had a 90’x4′ wall (360 SFF), he’s looking at approximately $12-16K.
Segmental retaining wall: these are your interlocking concrete wall systems, EP Henry, Techo-Bloc, or similar. Depending on a lot of variables, walls average from $50/SFF to $75/SFF. For our homeowner with 360 SFF of wall, we’re looking at approximately $18-27K.
Concrete retaining wall with stone veneer and cap: This is the most attractive type of wall, and one I’m a huge fan of. Costs vary by site conditions, stone used, etc., but I generally ballpark $75-105/SFF when discussing budgets. My sample homeowner with 360 SFF would be looking at a range of $27-38K.
There are other types of walls (boulder, dry-stacked fieldstone, poured and stamped concrete, etc) but the above are far and away the most commonly requested and built in the DC Metro area. As you can see, retaining walls have the potential to use a good portion of the budget for a landscape project. This is why good design is key. Not only can a good landscape master plan ensure that the walls are where they need to be and and properly designed, it can potentially reveal options for using fewer or smaller walls – freeing up funds for the more exciting parts of the project.