Where the exemption starts and stops
A one-story detached accessory structure not exceeding 120 square feet does not require a building permit in Plano. That threshold comes from IRC Section R105.2 as adopted by the City, and it is the reason a typical back-yard storage shed — a 10 by 12, an 8 by 12, a resin unit from a big-box store — needs no paperwork at all.
Everything above the threshold does need one. The City's permit-required list is explicit that an accessory building permit covers "permanent and portable storage sheds, gazebos, carports and patio covers," and the Miscellaneous Simple Permit Application carries a "Storage Building (Prefab)" checkbox. Portability is not an exemption. A 200-square-foot building that arrived on a trailer and sits on skids is an accessory building over 120 square feet, and Plano permits it as one.
The exemption is about form as much as area. It applies to a structure that is one story and detached; a two-story playhouse or a structure joined to the dwelling is outside it regardless of footprint.
On a shed of 120 square feet or less, a missing permit is not a finding. There is no permit to be missing.
The trap: exempt from the permit, not from the zoning ordinance
Here is the part that catches people, and it is stated plainly in Plano's own accessory building handout: the 120-square-foot exemption is an exemption from the building permit only. An exempt shed must still comply with all zoning ordinance requirements.
Those are two different bodies of rule, administered by two different parts of the City, answering two different questions. The building permit asks whether a structure is built to the adopted construction code. The zoning ordinance asks whether it is allowed to be there at all — where on the lot, how tall, how close to the line, how much of the lot it consumes, and what it may be used for.
Removing the first question does not touch the second. So a permit-exempt shed can be entirely legal to build and entirely illegal where it stands. That produces an unusual reading rule for a buyer: on a small shed the permit record is the wrong document to consult, because it will be blank whether the shed is compliant or not. The plat and a tape measure are the relevant instruments.
The zoning rules that apply either way
These bind whether or not a permit was ever issued.
| Subject | What the zoning rules require |
|---|---|
| Front yard | No accessory buildings in a required front yard |
| Side and rear setback | Minimum 3 feet from side and rear lot lines for carports and detached structures other than garages |
| Distance from the house | Enclosed detached buildings: minimum 10 feet from the main building |
| Alley-loaded garages | Minimum 20-foot setback from the alley lot line |
| Street-side yards | Not permitted in a required side yard setback adjacent to a street |
| Height | Maximum 10 feet for detached buildings in rear and side yards |
| Screening | Buildings less than 10 feet from a lot line require a 6-foot solid screening fence or wall; carport entries are exempt |
| Easements | Nothing within easements or rights-of-way |
| Lot coverage | PH and SF-A 60 percent total; SFR zones 65 percent; SF-20 45 percent; ED zones 20–25 percent — with garages and accessory buildings capped at 10 percent |
| Use | An accessory building may not be used for commercial purposes and may not be rented |
Three of these do most of the work in practice. The 3-foot side and rear setback is the one people cheat, because pushing a shed tight to the fence line is what a small yard invites. The screening rule is the one nobody has heard of. And the 10 percent cap on garages and accessory buildings is a separate ceiling sitting underneath the overall coverage figure, so a lot can be well within its total coverage and still be over on accessory structures.
What changes above 120 square feet
Once a building crosses the threshold, the ordinary permit machinery applies. Plano's accessory building requirements ask for two complete sets of scaled and dimensioned drawings, a permit application, a site plan at 1 inch = 20 feet, construction details including framing, foundations and electrical, exterior elevations, and manufacturer specifications where the building is prefabricated. Mechanical, plumbing and electrical fees apply where those trades are involved.
Two administrative rules attach. The permit expires after 180 days of inactivity. And failing to complete the required inspections results in a hold on the contractor's registration — Plano's lever for permits left open, and the reason a never-finaled accessory building permit is a more interesting entry in a record than a finaled one.
Carports are a related category with their own published rules: a carport may shelter no more than three vehicles and may not exceed 24 feet on its longest dimension, must be open on a minimum of three sides, and if it is a welded metal carport it must be designed and sealed by a State of Texas licensed engineer. Bolt-connected metal carports need detail information or manufacturer specifications instead.
Decks sit on a different threshold again. IRC R105.2 as adopted exempts a deck not exceeding 200 square feet, not more than 30 inches above grade, not attached to a dwelling, and not serving the required exit door. The City's plain-language list states the same rule from the other direction: decks exceeding 30 inches in height require a permit.
The same number, in a different rule
The figure 120 square feet turns up twice in Plano's residential amendments, in places that have nothing administratively to do with each other, and the second appearance is a useful check on what the City thinks the exemption is for.
Plano's amendment to IRC R902.1 requires Class A, B or C roof coverings — the classified fire ratings — and permits non-classified roof coverings only on one-story detached accessory structures of 120 square feet or less. The same building that needs no permit is the only one on a Plano lot that may carry an unrated roof.
Read together, those two rules describe a consistent judgement: a small, single-story, detached, unoccupied box in a back yard is treated by the code as a structure of minimal consequence. That is why the exemption exists, and also why the zoning rules survive it — the code stopped caring how the shed is built, not where it sits or what it blocks.
What the permit record shows here, and what it cannot
For an exempt shed, the record is silent by design, and the silence carries no information. That is different from most items in a permit history, where an absence is at least a question.
Plano's treatment of occupancy approval reinforces the point. In the City's amendments to the 2024 IRC, the requirement for an approval before a structure is used or occupied carries two added exceptions: none is required for work exempt from permits, and accessory buildings and structures do not require certificates. So there is no document to look for on a small shed, in either direction. Plano also issues no certificate of occupancy for a single-family home at all; the functional milestone for a house is an approved final inspection and the associated utility release.
Where a permit was required and issued — a building over 120 square feet — the record shows what it always shows: the work was declared, reviewed against the code edition in force on the issue date, and visited at hold points defined in a checklist supplied with the permit and not published. It does not show workmanship, durability, or anything the inspector was not there to look at.
What a private inspection is not required to cover
A shed is close to the clearest case in the Texas Standards of Practice. An inspector is not required to inspect "detached buildings, decks, docks, fences, waterfront structures, or related equipment." A detached shed can be omitted from an inspection report entirely, and the report is still complete and compliant.
Outbuildings do appear in the standards, but in the optional column: 22 TAC §535.233, "Minimum Inspection Requirements for Optional Systems," covers outbuildings alongside irrigation systems, swimming pools, private water wells and private sewage disposal. Optional means what it says — a buyer who wants a shed examined is arranging that specifically, not receiving it as part of the standard scope.
And the zoning question is outside the instrument entirely. An inspector is not required to determine compliance with any code, and a setback is not a condition. Nobody in a typical Plano transaction measures the distance from the shed to the lot line unless somebody chooses to.
When there is no shed permit in the record
At 120 square feet or less, the answer is nothing. There should be no permit, there is no permit, and the blank is the expected result. This is the clearest no permit expected item on a Plano property record, and treating it as a defect misreads the ordinance.
The question that survives is the zoning one, and it survives indefinitely. A permit obligation that was never triggered cannot lapse; a zoning non-conformity does not become conforming because time passed or because no permit was ever required. Setback, height, screening, easement encroachment and the accessory-structure coverage cap are all still live regardless of what the permit record says, and they are all measurable on the ground.
Where a shed is plainly larger than 120 square feet and there is no permit for it, the reading changes: a permit was required, no municipal inspector examined the structure, and every zoning rule above still applies. Plano's Property Standards Division, which sits within Neighborhood Services rather than Building Inspections, inspects residential property and takes complaints. What the City would require at a specific address is a question for Building Inspections, the only authority on its own rules and its own record. Nothing here is legal advice.
Common questions
Do I need a permit for a shed in Plano?
Not if it is a one-story detached accessory structure of 120 square feet or less. That threshold comes from IRC Section R105.2 as adopted by Plano, and it covers most ordinary back-yard storage sheds. Anything larger, anything with a second story, and anything attached to the dwelling requires a permit — and the exemption is from the building permit only, not from the zoning ordinance.
Does a portable or prefab storage building need a permit in Plano?
Portability makes no difference. Plano's permit-required list expressly covers accessory buildings “including permanent and portable storage sheds,” and the City's short-form permit application carries a Storage Building (Prefab) checkbox. A prefabricated building over 120 square feet needs a permit, and the submittal has to include the manufacturer's specifications.
How close to the fence can a shed be in Plano?
The zoning rules set a minimum of 3 feet from side and rear lot lines for detached structures other than garages, and nothing may sit within an easement. A second rule people miss: a building less than 10 feet from a lot line requires a 6-foot solid screening fence or wall. Both apply whether or not the shed needed a permit.
How tall can a shed be in Plano?
Detached buildings in rear and side yards are limited to a maximum of 10 feet in height under the zoning rules. Enclosed detached buildings must also sit at least 10 feet from the main building. Neither limit is affected by the 120-square-foot permit exemption, because both come from the zoning ordinance rather than the building code.
Can a permit-exempt shed still be in the wrong place?
Yes, and this is the trap. Plano's accessory building handout states directly that an exempt structure must still comply with all zoning ordinance requirements. Setbacks, height, screening, easements, lot coverage and the rule against commercial use or renting an accessory building all continue to apply. A shed can be lawfully built and unlawfully sited at the same time.
Does a missing shed permit matter when buying a Plano house?
On a shed of 120 square feet or less, no — there was never a permit to find, and the blank record means nothing. The useful question is a zoning one and it can be answered by measuring: how far the shed sits from the lot lines, whether it encroaches on an easement, how tall it is, and whether it needs the 6-foot screening fence. The permit record cannot answer any of those.
Do I need a permit for a deck in Plano?
The adopted exemption covers a deck not exceeding 200 square feet, not more than 30 inches above grade, not attached to a dwelling, and not serving the required exit door. All four conditions have to hold. The City's plain-language permit list states the practical version: decks exceeding 30 inches in height require a permit.