Fort Bend County offers a surprisingly streamlined permitting process for rural and unincorporated homeowners — provided you know the magic number.
That number is 400 square feet. Because the county has no zoning ordinances and no residential building codes, they only step in to regulate large structures, drainage, and safety. If your project crosses that threshold, you'll need to submit a site plan to the Engineering Department. Here is what they are looking for.
Do You Need a Site Plan for a Small Permit in Fort Bend County?
Under 400 sq ft: Generally, no. In unincorporated Fort Bend County, sheds, decks, and accessory structures under 400 square feet may not require a Development Permit (as long as they don't involve re-grading, drainage modifications, or floodplain work).
400 sq ft and over: Yes. Any new structure or addition that meets or exceeds 400 square feet requires a Residential Development Permit. Your application must include one (8‑1/2″ × 14″) plot plan/survey drawn to scale locating new and existing structures.
The site plan must show:
- Lot lines with accurate dimensions
- All structures on the property with dimensions
- Distances from proposed structures to property lines (setbacks)
- Utility, drainage, and access easements
- Floodplain information (if applicable)
Who Runs Into This in Fort Bend County
- Sugar Land homeowners who read the county's "no permit under 400 sq ft" rule online, only to be cited by the city because Sugar Land has much stricter municipal codes
- Rural property owners building large steel workshops who assume "no building code" means they can build right on the property line (the county still enforces setbacks)
- Homeowners adding a driveway who don't realize that a new connection to a county road requires a $150 residential driveway permit and a site plan
- Builders in new subdivisions trying to navigate the county's strict minimum slab elevation requirements for drainage
What Needs a Site Plan in Unincorporated Fort Bend County
- Fence permit site plan — May not require a county permit unless crossing an easement, but highly recommended to verify property lines. (HOA rules often require site plans for fences).
- Shed permit site plan — Required for sheds 400 sq ft or larger. Must show setbacks and easements.
- Deck permit site plan — Required for decks 400 sq ft or larger.
- Pool permit site plan — Required. Must show pool location, setbacks, equipment layout, and barrier plan.
- Garage permit site plan — Required for garages over 400 sq ft. Must show driveway location and setbacks.
- Addition permit site plan — Required for additions 400 sq ft or larger. Must show existing house, addition footprint, setbacks, and floodplain compliance.
- Driveway permit site plan — Required for new connections to county roads.
Why This Trips People Up in Fort Bend County
The City vs. County divide. Fort Bend County has over 30 incorporated cities (Sugar Land, Missouri City, Katy, Richmond). If you live inside city limits, the county Engineering Department does not handle your permit. You must follow the city's specific rules. Always verify your jurisdiction on the Fort Bend County Appraisal District (CAD) site first.
Drainage Easements. Because there is no zoning, the county's primary concern is drainage. All drainage easements must be kept completely clear of fences, buildings, and vegetation. If your site plan shows a structure encroaching on a drainage easement, it will be rejected.
Slab Elevation Rules. To prevent flooding, the county has strict rules about how high your foundation must be. The top of all floor slabs must be a minimum of 24 inches above the lowest top of curb adjacent to the lot. If there is no curb, it must be 24 inches above natural ground. Your site plan may need to note these elevations.
Address Verification. For new structures, Fort Bend County requires an address verification letter from the CenterPoint Addressing Department before issuing a permit.
Zoning and Setbacks in Unincorporated Fort Bend County
Since the county has no zoning ordinances, setback rules are dictated by the county's subdivision regulations and design criteria:
General Setbacks (Local Streets):
- Front setback: 25 feet from the adjacent street right-of-way (can be reduced to 20 ft if the ROW is 60 ft wide)
- Side setback: 10 feet
- Rear setback: 10 feet
- Distance between dwellings: Minimum 10 feet
Major Thoroughfares:
- Front setback: 25 feet
- Side setback: 20 feet
- Rear setback: 10 feet
Crucial Note: Many platted subdivisions have their own specific setback restrictions written into the deed that supersede the county's general rules. Always check your subdivision plat.
How the Tool Handles This — 5 Steps
SitePlans.ai loads Fort Bend County parcel data so you're starting from your actual property boundaries:
- Enter your address — Lot lines and existing building footprints load from county records.
- Place your project — Add your shed, pool, or addition to the lot.
- Set the required setbacks — The tool calculates distances to property lines so you can verify compliance with the 25-foot front and 10-foot side/rear rules.
- Add easements — Manually label utility and drainage easements to show the county you are avoiding them.
- Export a scaled PDF — Download a titled, scaled plan (e.g., 8.5" x 14" format) ready for upload to the MGO Connect portal.
Where This Tool Fits — and Where It Doesn't
| Situation | Best path |
|---|---|
| Unincorporated shed, deck, or addition (>400 sq ft) | SitePlans.ai for the required site plan; non-certified plans accepted |
| Project inside Sugar Land or Missouri City | SitePlans.ai for layout; verify city-specific sealed plan requirements |
| Commercial developments & roadways | Licensed civil engineer required (civil site plans mandatory) |
| Work within the 100-yr floodplain | Licensed surveyor/engineer required (elevation documentation) |
| Property line dispute or unclear boundaries | Licensed land surveyor |
| Plan rejected in MGO Connect | SitePlans.us for human-reviewed revision |
What This Doesn't Replace
SitePlans.AI helps create preliminary, conceptual, permit-style site plans for standard residential projects where local rules allow homeowners or Contractors prepared drawings. It is not a licensed land survey, sealed engineering drawing, PE/PLS/architect stamp, or a guarantee of permit approval. If your project involves floodplain development, complex grading, or commercial infrastructure, you must hire a licensed professional.
Comparison: Your Options for a Fort Bend County Site Plan
| Method | Cost | Time | Stamp | Notes |
|---|---|---|---|---|
| Hand sketch | Free | 1–2 hrs | ✗ | Allowed by county, but must accurately show setbacks and easements |
| SitePlans.ai | Free first plan | Minutes | ✗ | Pulls CAD parcel data; perfect for standard Development Permits |
| CAD drafter | $300–$800+ | 1–2 weeks | Sometimes | Better for complex additions |
| Licensed surveyor/engineer | $500–$2,000+ | 1–3 weeks | ✅ | Mandatory for commercial projects and floodplain work |
| SitePlans.us (done-for-you) | Custom | 1–3 days | ✗ (human-reviewed, non-certified) | Best for responding to MGO Connect correction notices |
Common Mistakes That Delay Fort Bend County Permits
- Applying to the wrong office — Assuming the county issues your permit when you actually live inside Katy or Richmond city limits.
- Ignoring the 400 sq ft rule — Building a 500 sq ft workshop without a Development Permit.
- Building in a drainage easement — The county's biggest concern is drainage. Encroaching on an easement guarantees a rejection.
- Missing the CenterPoint letter — Forgetting to secure an address verification letter for a new structure before applying.
- Not checking the subdivision plat — Assuming the county's 10-foot side setback applies, when your specific subdivision plat requires 15 feet.
Support and Local Resources
- Fort Bend County Engineering — fortbendcountytx.gov — handles unincorporated Development Permits
- MGO Connect Portal — mgoconnect.org — for online submissions
- Fort Bend Central Appraisal District (CAD) — fbcad.org — verify jurisdiction and parcel boundaries
- Fort Bend County GIS Hub — fortbendcountytx.gov/gis — check floodplains and subdivisions
- FEMA Flood Maps — msc.fema.gov
Nearby Counties
- Harris County site plan guide — Northeast of Fort Bend
- Texas permit site plan requirements
- Dallas County site plan guide
- Denton County site plan guide
- Travis County site plan guide
- Montgomery County site plan guide — North; planned
Frequently Asked Questions
1. Does unincorporated Fort Bend County require a building permit for a shed?
Only if it meets or exceeds 400 square feet. Structures under 400 sq ft generally do not require a Development Permit, provided they don't involve grading, drainage changes, or floodplain work.
2. Does Fort Bend County have a residential building code?
No. Unincorporated Fort Bend County has not adopted zoning ordinances or building codes for single-family residential developments. However, they do enforce subdivision regulations, setbacks, and drainage rules through the Development Permit process.
3. Does Fort Bend County accept homeowner-drawn site plans?
Yes. For standard residential Development Permits, the county accepts site plans prepared by the homeowner or contractor, provided they are drawn to scale and clearly show property lines, structures, setbacks, and easements.
4. How do I know if I'm in a city or unincorporated Fort Bend County?
Look up your address on the Fort Bend Central Appraisal District (CAD) website. The taxing entities listed will confirm whether you are inside an incorporated city limit (like Sugar Land or Missouri City).
5. What are the setbacks for a pool or shed in unincorporated Fort Bend County?
Generally, 10 feet from the side and rear property lines, assuming there are no conflicting easements or stricter subdivision plat rules. Front setbacks are typically 25 feet.
6. Do I need a permit for a driveway?
Yes, if it connects to a county-maintained road. You must obtain a residential driveway permit ($150 fee) to ensure proper drainage and culvert installation.
7. Can I use SitePlans.ai for a Fort Bend County permit?
Yes. For unincorporated projects, SitePlans.ai is an excellent tool to pull your CAD parcel data, layout your project, mark the required 10-foot or 25-foot setbacks, and generate the PDF required for MGO Connect.
8. What if my property lines look wrong in SitePlans.ai?
GIS parcel data is a representation, not a legal survey. If your boundaries look significantly off in the tool, verify them against Fort Bend CAD. If you are building very close to a setback line or an easement, you must hire a licensed land surveyor.
9. What is SitePlans.us and when should I use it?
SitePlans.us is our done-for-you drafting service. If your application is rejected for site plan inaccuracies, or if you simply don't want to draw it yourself, our team will draft a permit-ready (non-certified) plan fast.
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Start Your Fort Bend County Site Plan
Check your jurisdiction on the Fort Bend CAD site first. If you're ready to draft your site plan, enter your address below to pull your property lines, place your project, label your setbacks and easements, and download the PDF you need for MGO Connect.
Build My Fort Bend County Site Plan →
Got a correction notice from the county? Send the comments to SitePlans.us and we'll draft the revision for you.
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