Residential

Retaining Wall Design

A licensed engineer designs retaining walls that hold back soil safely, with stamped plans your building department will accept. Typical US fees run $500 to $5,000, and most projects take 1 to 4 weeks for design, plus permit review time. Our drawings, calculations and reports are sealed by a Professional Engineer (PE) licensed in the state where your project is located, ready for permit submission.

Typical US fee$500 to $5,000
Typical timeline1 to 4 weeks for design, plus permit review time
Permit drawingsSealed by a PE

What the work involves

A civil or structural engineer sizes the wall, footing, reinforcement, geogrid and drainage for the soil and loads behind it, then stamps drawings and calculations for the permit. The design accounts for wall height, soil type, slope above the wall, nearby driveways or buildings (surcharge) and groundwater. Many walls fail from poor drainage rather than weak blocks, so the engineer specifies gravel backfill, filter fabric and a drain pipe. Most jurisdictions require a PE stamp once a wall crosses the local height or surcharge threshold.

When you need it

  • Wall taller than 4 ft measured from the bottom of the footing to the top of the wall (the International Residential Code permit exemption limit adopted by many jurisdictions)
  • Any wall supporting a surcharge such as a driveway, parking area, building, pool or sloping ground above it
  • Tiered or terraced walls where the upper wall loads the lower one
  • Walls on or near a property line, easement or public right of way
  • Segmental block walls using geogrid reinforcement, which manufacturers and building departments usually require to be engineered

What you receive

  • Stamped wall plans and sections
  • Structural and stability calculations (sliding, overturning, bearing, global stability)
  • Drainage and backfill details
  • Geogrid layout for segmental walls
  • Construction observation letter if required

What drives the cost

HomeServe (citing HomeGuide) puts a professional engineer for a retaining wall at $500 to $2,000 or more. Tall, tiered or surcharged walls that need a geotechnical report or global stability analysis can cost more; the upper figure is an estimate. Wall construction itself is separate (HomeAdvisor reports an average near $6,000).

Related calculators

Concrete Block (CMU) CalculatorCount 8x8x16 concrete masonry units (CMU) for a wall from its length, height and openings, with a waste allowance.Retaining Wall Block CalculatorEstimate segmental retaining wall blocks, courses and cap units from wall length, height and block face size.

Frequently asked questions

How much does retaining Wall Design cost?

Across the US, retaining Wall Design usually costs $500 to $5,000. HomeServe (citing HomeGuide) puts a professional engineer for a retaining wall at $500 to $2,000 or more. Tall, tiered or surcharged walls that need a geotechnical report or global stability analysis can cost more; the upper figure is an estimate. Wall construction itself is separate (HomeAdvisor reports an average near $6,000).

How long does retaining Wall Design take?

Plan on 1 to 4 weeks for design, plus permit review time from signed proposal to stamped deliverables, longer if a site visit, soil testing or a permit review cycle is involved.

Do I need a licensed PE for retaining Wall Design?

In most US jurisdictions, yes. When the work needs a permit, the plans, calculations or report usually must be sealed by a Professional Engineer licensed in the state where the project is located. Every deliverable we issue for permit is sealed that way.

Will I also need a geotechnical engineer?

Sometimes. Depending on the site, retaining Wall Design can also involve a geotechnical engineer, structural engineer, land surveyor or landscape architect. We tell you up front which other professionals your project needs and coordinate with them so the drawings agree.

Who do you provide retaining Wall Design for?

Most of our clients for this service are homeowners, contractors, developers and municipalitys. Describe your project and one of our engineers will reply with scope, fee and schedule.

How tall can a retaining wall be before I need an engineer?

Under the International Residential Code, a wall that is not over 4 ft from the bottom of the footing to the top of the wall and does not support a surcharge is exempt from a permit. Many cities and counties amend that limit, and some require engineering at lower heights, so confirm with your local building department.

What counts as a surcharge?

A surcharge is extra load on the soil behind the wall, such as a driveway, parked cars, a building, a pool or an upward slope. Even a short wall can need engineering when it carries a surcharge, because the added load increases the pressure on the wall.

Can a landscaper build the wall from my engineer's plans?

Usually yes. The engineer provides the design and the contractor builds to it. Some jurisdictions also ask the engineer to observe the geogrid and drainage installation and issue a letter before final inspection.

Why do retaining walls fail?

Common causes are water pressure building up behind the wall, missing or clogged drainage, footings that are too small, and loads that were not accounted for. An engineered design addresses each of these with drainage details and calculations.

Do I also need a geotechnical report?

For most short residential walls the engineer can use conservative assumed soil values. Tall walls, walls on slopes, or sites with clay, fill or groundwater often call for soil borings and a geotechnical report.

Where we provide this service

Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware District of Columbia Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming

Sources