Do We Need Permits to Build These Retaining Walls? Allen and Nearby Cities

The yard slopes, the bed along the fence keeps washing onto the patio, and you've finally got a plan: a short block wall to hold it all back. Then somebody at the cookout asks whether you pulled a permit, and you realize you have no idea. It's the same thing one homeowner typed word for word when they were planning theirs: "Do we need permits to build these retaining walls?"

It's a fair question, and around here the answer depends on which side of a city line your house sits. Allen, McKinney, Plano and Dallas don't all say the same thing, and the way the wall gets measured catches a lot of people out, so it's worth ten minutes before anyone starts digging.

The short answer, before the details

Do we need permits to build these retaining walls?

It depends on the city. McKinney requires a permit for every retaining wall regardless of height, and engineered plans once a wall is over 2 feet. Allen doesn't list retaining walls among the work that's exempt from permits, so call Allen Building and Permitting at 214.509.4130 with your wall's height before anyone digs.

What the cities around Allen say

McKinney is the simplest because it says it outright on the city's own page: "A permit for any retaining wall is required in the City of McKinney, regardless of height. Retaining walls more than two feet in height require engineered plans." That means even a knee-high planter wall needs a permit there, and a wall taller than your knee usually means an engineer drawing it before the city will look at it. McKinney Building Inspections is at 469-617-4800, and the city says to ask for a plans examiner. If you're over that way, the McKinney page has the rest of what to plan around.

Allen works on the 2021 International Residential Code with its own local amendments, and the city keeps a short list of residential work that doesn't need a permit. Decks, sheds and some minor plumbing are on it. Retaining walls aren't. That doesn't automatically mean every wall in Allen needs one, but it does mean the answer has to come from the city, not from a forum or a neighbor who built one years ago. Call Allen Building and Permitting at 214.509.4130 and give them the wall's height, its length and what sits above it.

A lot of other North Texas cities draw the line at 4 feet. Carrollton's page says "A permit is required for retaining walls four feet (4') or greater in height, measured from the bottom of the footing to the top of the wall, or which support a surcharge." Prosper uses the same 4-foot line measured from the footing, and Corinth requires a wall that tall to be "designed by a professional engineer" with sealed plans.

For Plano and Dallas, call the city's building inspections office before you build and describe the wall. You'll see plenty of websites saying walls under 4 feet never need a permit anywhere in Texas, and that's not something to rely on here when McKinney, right next door, permits all of them. The retaining wall and hardscaping page keeps the city-by-city list in one spot.

Why a 3-foot wall can count as a 4-foot wall

Notice the wording in those city rules: measured "from the bottom of the footing to the top of the wall." The footing is the buried part. On a block wall, the first course or two sits below grade on a bed of compacted gravel, so a wall you see as 3 feet tall can easily measure 4 feet or more by the city's tape.

That's the most common way people get caught. They look at the finished height, decide it's under the line, and build. Someone in a thread about wall heights did the math: "So if you want a 4' wall but need a foot underground for the base, then you can only go up 3'." Ask the pro to measure it the way your city does, from the bottom of the footing, and to write that number on the quote.

The other word to watch is "surcharge." It means extra weight on the soil behind the wall: a driveway, a parked car, a slope that keeps rising above the wall, a pool deck or a shed. A wall carrying a surcharge is working harder than one holding back a flat flower bed, and in several cities it needs a permit or an engineer even when it's short. Carrollton adds one more that comes up a lot around here, where cedar board-on-board fences line most backyards: if a fence goes "on top of or through" a retaining wall that needs a permit, "a Professional Engineer must approve" the wall's design.

Why the city cares, on clay

It can feel like paperwork for a garden wall, but the clay under Allen and Dallas is the reason these rules exist. It swells when it's wet and shrinks and cracks when it's dry, and a wall holding back saturated clay is holding back a lot of weight. "Clay is prone to hold water and settle," as a DIYer wrote, and the same shrink and swell is behind pavers that shift after their first year.

When a wall fails here, water is usually behind it, and the block is rarely the problem. "My retaining wall has started to lean," a homeowner wrote about a wall built with their house in 2000, and the threads are full of the same story: no gravel behind it, no drain pipe, "no filter fabric," so the clay stayed wet and pushed. The permit and the engineering for taller walls are there to make sure the footing, the drainage and the backfill get drawn and checked, which happens to be exactly what you'd want anyway. Permits follow the house, too. Someone thinking about resale put it this way: "when it's time to sell the house I'll have to declare if I'm aware of any non-permitted work done."

The HOA is a separate yes

A city permit and HOA approval are two different things, and having one doesn't get you the other. If you're in an HOA, read its rules or ask the management company whether it wants to see plans before the wall goes in. A homeowner in one thread found out halfway through the job, when "I got the HOA notice saying you did not get prior approval to build a retaining wall" and was told to stop work and file a new form.

Sort out who owns what, too. Someone whose wall was failing wrote, "My HOA is saying they are not responsible, my homeowner's insurance does not cover it, and the builder says they are not liable." If your wall is close to a shared fence, a common area or a neighbor's yard, find out before the build whose wall it is and who'll maintain it.

What to ask before anyone digs

A reply in a thread about hiring for a wall put it in two lines: "Make sure they include permits. Make sure they include drainage at the base of the wall." When a pro comes out, these are the questions worth asking:

• Does this wall need a permit in my city, measured from the bottom of the footing, and who pulls it?
• Is the permit, and the engineering if it's needed, included in the written price?
• What goes behind the wall: gravel backfill, a perforated drain pipe and filter fabric?
• How deep does the footing go, and what's it sitting on?
• Is there a fence, a driveway or a slope above it that counts as a surcharge?

A good crew answers those without hesitating and puts the answers on paper, so the permit isn't a surprise like it was for the homeowner who wrote, "I'm told I need a permit for the retaining wall which I wasn't accounting for." Be wary if you're asked to pull it yourself. As one reply put it, "Hiring someone that asks the home owner to pull permit is a red flag, friend or not." And if someone tells you a permit is never needed for a wall your size, ask them which city rule says so.

If you're planning a wall, or one that's already there has started to lean, a pro can measure it the way your city does and tell you whether you're looking at a permit, an engineer or neither. The retaining wall and hardscaping page walks through the drainage and footing in more detail. Call (469) 283-6279 and we'll connect you with a paver and hardscape pro serving Allen, or send a note through contact us.