In unincorporated Texas counties, building regulations work differently than in many other states. Without general zoning powers, Montgomery County regulates development through Environmental Health and Floodplain Administration, requiring residential development permits for new homes, accessory buildings, additions, and septic systems.
If your project is in unincorporated Montgomery County—whether in Magnolia, New Caney, Pinehurst, or rural acreage surrounding Conroe—you must comply with specific county submittal formats. The county strictly requires documents to be formatted on paper no larger than legal-size (8.5" × 14"), and any work near watercourses triggers meticulous floodplain reviews.
Do You Need a Site Plan for a Small Permit in Montgomery County?
Yes. The Montgomery County Permit Department requires a site plan or property survey for all residential building and development permit applications.
Your site plan must display:
- Exact location of all structures, clearly distinguishing existing structures from proposed additions or accessory units.
- Formal legal description identifying the recorded subdivision name, section, block, and lot number, or metes-and-bounds survey callouts.
- Property boundary lines with exact dimensioned distances.
- Setbacks indicating clear measurements from every structure to the property lines.
- Easements and rights-of-way (utility corridors, pipeline rights-of-way, drainage easements).
- Floodplain boundaries, indicating whether any portion of the parcel lies within the 100-year or 500-year flood zone.
- Driveway access points and road frontages, noting TXDOT rights-of-way where applicable.
- On-site sewage facilities (OSSF) showing septic tanks, spray fields, or drainfields relative to structures.
Key document standard: All plan sheets submitted to the Montgomery County Permit Department must be formatted to legal-size paper (8.5" × 14") or smaller. Oversized architectural sheets submitted for unincorporated residential permits will be rejected at the counter or portal.
Who Runs Into This in Montgomery County
- Suburban builders in The Woodlands who secure county development approval but fail to check covenant restrictions enforced by The Woodlands Township Development Standards Committee.
- Acreage owners who construct a 20x30 storage barn without realizing that even detached accessory structures require a county residential development permit.
- Lake Conroe and San Jacinto River basin residents whose parcels touch FEMA 100-year floodplains, triggering mandatory elevation certificates and an increased permit fee.
- Applicants who submit large blueprint sheets (24" × 36"), unaware that county document scanning systems are strictly configured for legal-size (8.5" × 14") filings.
What Needs a Site Plan in Montgomery County
- Shed & Detached Garage site plan — Required for detached storage buildings, workshops, and pole barns in unincorporated areas.
- Deck & Patio site plan — Required for structural patio covers and elevated decks.
- Pool permit site plan — Required for all swimming pools; must show safety barriers, setback lines, and flood zone boundaries.
- Addition permit site plan — Required for building footprint expansions, room additions, or attached garage conversions.
- Driveway Access — A TXDOT Driveway Permit is mandatory if new driveway access connects to a state-maintained roadway.
- On-Site Sewage Facilities (OSSF) — Required for septic installations, mandating precise buffer distances from buildings and property boundaries.
Why This Trips People Up in Montgomery County
The 8.5" × 14" Legal-Size Limit. Unlike western jurisdictions that demand large architectural sheets, Montgomery County requires plans formatted to legal size (8.5" × 14") or standard letter size (8.5" × 11"). Submitting 18" × 24" or 24" × 36" drawings causes immediate processing snags.
Floodplain Administration Rules. With the San Jacinto River, Lake Conroe, Spring Creek, and Caney Creek crisscrossing the county, flood zones are pervasive. If your property touches the 100-year floodplain:
- The residential development permit fee increases from $150 to $200.
- A dedicated floodplain development permit is required.
- Finished floor elevations must be established above the Base Flood Elevation (BFE) using a certified FEMA Elevation Certificate.
City ETJ (Extraterritorial Jurisdiction). Properties in unincorporated areas that lie within the ETJ of cities like Houston or Conroe may require a Form 101 or Certificate of Compliance confirming that city platting rules have been satisfied before the county can issue development permits.
HOA and Deed Restrictions. In Texas, county government does not enforce private deed restrictions. However, master-planned developments (especially The Woodlands) have strict covenant enforcement. A county development permit does not override private HOA setback or design restrictions.
Setbacks in Montgomery County
In unincorporated Texas counties without formal zoning categories, setbacks are established by recorded subdivision plats, deed restrictions, or county development regulations:
General County Baseline Standards:
- Front yard: Typically 25 to 50 feet depending on roadway classification and recorded subdivision plat lines.
- Side yard: 5 to 15 feet as determined by subdivision restrictions.
- Rear yard: 15 to 25 feet.
- Accessory structures: Minimum 5 feet from interior side and rear lot lines, provided no structures encroach into designated drainage or utility easements.
- Accessory structure height: Shall not exceed 1-1/2 stories or 14 feet in height unless specific variances apply.
How the Tool Handles This — 5 Steps
SitePlans.ai utilizes Montgomery County Appraisal District (MCAD) parcel mapping to draft compliant legal-size site plans:
- Enter your address or MCAD Account Number — Boundary lines load from county GIS data.
- Place your Structures — Position your main dwelling, detached shop, pool, or patio addition.
- Add formal legal descriptions — Automatically import your lot, block, section, and subdivision information.
- Mark easements and flood zones — Identify FEMA flood hazard zones and utility buffer corridors.
- Export to Legal Size — Download a PDF formatted to 8.5" × 14" ready for upload to the Montgomery County Development Permits Portal.
Where This Tool Fits — and Where It Doesn't
| Situation | Best path |
|---|---|
| Shed, pool, garage, or addition in unincorporated Montgomery County | SitePlans.ai for the required legal-size site plan |
| Checking parcel boundaries and flood zones before building | SitePlans.ai for initial spatial analysis |
| Projects inside the 100-year floodplain requiring an Elevation Certificate | Registered Texas Surveyor or Civil Engineer required |
| New commercial developments or formal subdivisions | Registered Professional Land Surveyor (RPLS) required |
| Boundary disputes or unverified fence line locations | Licensed Texas RPLS required |
What This Doesn't Replace
SitePlans.AI provides conceptual and layout site plans for residential permitting in unincorporated Montgomery County. It is not an official boundary survey performed by a Registered Professional Land Surveyor (RPLS), nor does it supply stamped FEMA Elevation Certificates required for flood zone construction.
Comparison: Your Options for a Montgomery County Site Plan
| Method | Cost | Time | Stamp | Notes |
|---|---|---|---|---|
| Hand sketch on legal paper | Free | 1–2 hrs | ✗ | Allowed outside floodplains; must be clear and drawn to scale |
| SitePlans.ai | Free first plan | Minutes | ✗ | Formatted directly to 8.5" × 14" with legal descriptions and setbacks |
| Local Drafter | $250–$600 | 1–2 weeks | Sometimes | Suitable for complex custom additions |
| Texas RPLS Boundary Survey | $600–$1,800 | 2–4 weeks | ✅ | Mandatory for new home construction and flood elevation certs |
| SitePlans.us (done-for-you) | Custom | 1–3 days | ✗ | Fast turnkey solution if portal submittal requires revisions |
Common Mistakes That Delay Montgomery County Permits
- Submitting oversized plan sheets — Submitting sheets larger than 8.5" × 14" for unincorporated county review.
- Omitting the legal description — Failing to state the recorded subdivision, section, block, and lot on the face of the plan.
- Ignoring the floodplain status — Not checking whether part of the parcel falls into the 100-year flood zone.
- Encroaching into utility easements — Placing an accessory shed or pool within a recorded pipeline or drainage easement.
- Failing to coordinate with TXDOT — Installing a new driveway on a state highway without a separate TXDOT driveway permit.
Support and Local Resources
- Montgomery County Permit Department — 501 N. Thompson, Suite 100, Conroe, TX 77301 | (936) 539-7836
- Development Permits Portal — mctx.org/online_services/permits.php
- Montgomery County Appraisal District (MCAD) — mcad-tx.org
- FEMA Flood Map Service Center — msc.fema.gov
Nearby Counties
- Texas permit site plan requirements
- Dallas County site plan guide
- Denton County site plan guide
- Travis County site plan guide
Frequently Asked Questions
1. Does Montgomery County have formal zoning?
No. Unincorporated Montgomery County does not have traditional zoning classifications. Land use and construction are governed by residential development regulations, subdivision plat restrictions, and floodplain management rules.
2. What paper size is required for site plans?
All permit submittal documents, including site plans, must be no larger than legal-size paper (8.5" × 14").
3. Do I need a permit for a storage shed in Montgomery County?
Yes. In unincorporated Montgomery County, detached accessory structures, including sheds and workshops, require a residential development permit.
4. How does the floodplain affect my permit?
If any part of your building site is in the 100-year floodplain, an additional floodplain development permit and a certified FEMA Elevation Certificate are required, and the permit fee increases from $150 to $200.
5. Does a county permit cover The Woodlands?
No. While you must comply with county development regulations, properties within The Woodlands Township must also obtain separate approval from The Woodlands Township Development Standards Committee.
6. Can I use SitePlans.ai for my Montgomery County permit?
Yes. SitePlans.ai produces a scaled, fully dimensioned site plan formatted specifically to 8.5" × 14" legal paper with required legal descriptions and setback measurements ready for the online permits portal.
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