Bolthole Index

Montgomery County, Texas

Zoning, building permits and septic rules in Willis, Texas

The City of Willis, in Montgomery County, Texas, sets its own zoning districts1 and requires a building permit, issued by its Building Official, before any structure is erected, moved, added to or structurally altered2. Septic permits are a separate question: we could not confirm who issues them inside city limits, so ask Montgomery County Environmental Health3.

At a glance

Building permit
Required inside Willis city limits; the Building Official issues it2
Zoning
Yes: the City divides Willis into zoning districts (R-1, R-2, MH, HD, GC, GI)4
Certificate of occupancy
Required before occupancy, use or change of use5
Septic
Not confirmed inside city limits; Montgomery County Environmental Health is the permitting office for the county3
RV living
Limited rules for RVs in manufactured-home parks; other RV use not confirmed6
Manufactured homes
Use and occupancy permit required from the Building Official7
Owner-builder trades
State licensing exemptions for owners' own homes; no Willis exemption confirmed8

Who to call

Building permits

City of Willis Permit Office

Building permit applications and contractor registration for property inside Willis city limits, filed online through the city's GovWell portal.

936-856-4611

[email protected]

501 W. Montgomery St., Willis, TX, 77378

Online permits →

Planning & zoning

City of Willis Planning & Zoning (Community Development)

Zoning regulations, subdivision regulations and plats inside Willis city limits.

936-856-4611

501 W. Montgomery St., Willis, TX, 77378

Septic permits

Montgomery County Environmental Health Services (On-Site Sewage Facilities)

Septic (on-site sewage facility) permits and inspections across Montgomery County as local agent for the state.

936-539-7839

501 N Thompson Street, Suite 101, Conroe, Texas 77301

Contact details are copied from each office’s official page and were checked against it on October 24, 2026.

Off-grid gear

Going off-grid in Willis means bringing your own water and power. The kit we’d start with:

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Does Willis, Texas have zoning, and what does it mean for RVs, tiny homes and setbacks?

Yes. The City of Willis divides land inside city limits into zoning districts1: R-1 and R-2 (single-family residential), MH (manufactured home), HD (high-density residential), GC and GI4.

Setbacks depend on the district. In the R-1 district, a structure must sit at least 25 feet from the front lot line, with side setbacks of at least 5 feet and rear setbacks of at least 10 feet9. In the R-2 district, structures may not exceed 35 feet in height10.

For RVs, Willis ties its rule to manufactured-home parks: each recreational vehicle in a park needs a permanent label and current state registration, while RVs outside a park that are not lived in full time are exempt6. We could not confirm any Willis rule on tiny homes or full-time RV living on an ordinary lot, so ask the City's planning office before you buy.

Do you need a building permit in Willis, and who issues it?

Yes. Inside Willis city limits, no building or other structure may be erected, moved, added to or structurally altered without a permit, and the Building Official issues it2. Applications must include an accurate plot plan, and the lot's dimensions must rest on a survey by a registered state surveyor, with the lot staked before construction begins11.

Before anyone occupies a new or altered building, or changes how it is used, the City also requires a certificate of occupancy or completion5. Applications go through the City's online GovWell portal, and the Willis Permit Office answers questions12.

The county's development permit does not apply here: Montgomery County's permit covers unincorporated land, and the county packet notes that property inside a city's jurisdiction may need additional documentation13.

How do septic permits work inside Willis?

We could not confirm whether the City of Willis or Montgomery County issues septic permits for property inside city limits, or whether a given lot is on city sewer. Treat this as the first call to make.

Montgomery County Environmental Health issues septic permits and approvals for the county, and states that it serves as local agent for the Texas Commission on Environmental Quality14. A new system there needs a site evaluation and soil analysis, plus a design by a Registered Sanitarian or Registered Professional Engineer15. The county will not permit a septic system in the regulatory floodway3.

Soils matter too. Only about 2% of soils in Montgomery County rate as not limited for a conventional drain field, so expect a site evaluation and often an engineered system rather than a simple one16. Call17 with your address before making an offer.

Can you put a manufactured home on a lot in Willis?

Possibly, with conditions. No manufactured home may be lived in within Willis unless the Building Official has first issued a use and occupancy permit7. A pre-owned manufactured home must also pass a property inspection report prepared by a licensed inspector before that occupancy permit issues18.

Outside manufactured-home parks, the permit conditions include skirting and at least 200 cubic feet of accessory storage7. The City's MH district is the zoning district for manufactured homes4; confirm that a specific lot sits in it with the Planning & Zoning office19.

Building a home in Willis: the steps, in order

  1. Confirm the lot's zoning district and setbacks with the City's Planning & Zoning division19.
  2. Ask whether the lot is on city sewer; if not, call Montgomery County Environmental Health about a septic permit3.
  3. Get a survey and a plot plan, and apply for the building permit through the City's online portal11.
  4. Build to the permit; the Building Official issues it2.
  5. Obtain the certificate of occupancy or completion before anyone moves in5.

If you divide land, the City's subdivision chapter covers preliminary plans, final plats, variances and replats20.

What stays with Montgomery County, and what to check before you buy in Willis

Land outside Willis city limits is a different case. Unincorporated Montgomery County has no county zoning21, so none of Willis's district rules follow a lot across the city line. For the county's rules on unincorporated land, see the Montgomery County page.

Check whether the lot is in a floodplain: the county's floodplain regulations apply to unincorporated areas, and we could not confirm which floodplain rules the City applies inside its limits, so ask the Willis Permit Office22.

For carrying costs, Montgomery County's effective property tax rate is 1.6%23; confirm the rate for the specific address with the county appraisal district.

Watch-outs

  • We could not confirm who issues septic permits for property inside Willis city limits, so call Montgomery County Environmental Health and the Willis Permit Office before relying on either3.
  • We could not confirm Willis rules on tiny homes, accessory dwellings, minimum dwelling size, driveways or private wells inside city limits; ask the City's Planning & Zoning division19.
  • A county development permit or county 'no zoning' answer does not apply inside Willis; the City's own zoning and building permit rules control2.

Sources

  1. Willis Code of Ordinances, § 155.145 Establishment of zoning districts and boundaries (Willis), quoted and re-checked
  2. Willis Code of Ordinances, § 155.070 Required (Willis), quoted and re-checked
  3. How to Obtain a Septic Permit and On-Site Sewage Facility Fees, quoted and re-checked
  4. Willis Code of Ordinances, § 155.145 Establishment of zoning districts and boundaries (Willis), quoted and re-checked
  5. Willis Code of Ordinances, § 155.090 Certificates of occupancy or completion (Willis), quoted and re-checked
  6. Willis Code of Ordinances, § 155.151 Manufactured Home MH District (Willis), quoted and re-checked
  7. Willis Code of Ordinances, § 155.151 Manufactured Home MH District (Willis), quoted and re-checked
  8. Exemptions to Electrician Licensing (2026 county census)
  9. Willis Code of Ordinances, § 155.149 R-1 Residential District (Willis), quoted and re-checked
  10. Willis Code of Ordinances, § 155.150 R-2 Residential District (Willis), quoted and re-checked
  11. Willis Code of Ordinances, § 155.070 Required (Willis), quoted and re-checked
  12. City of Willis Permit Office (ci.willis.tx.us)
  13. Montgomery County Development Permit Procedures, quoted and re-checked
  14. On-Site Sewage Facility, quoted and re-checked
  15. How to Obtain a Septic Permit and On-Site Sewage Facility Fees, quoted and re-checked
  16. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  17. Montgomery County Environmental Health Services (On-Site Sewage Facilities) (mctx.org)
  18. Willis Code of Ordinances, § 155.151 Manufactured Home MH District (Willis), quoted and re-checked
  19. City of Willis Planning & Zoning (Community Development) (ci.willis.tx.us)
  20. Willis Code of Ordinances, Chapter 154: Subdivision Regulations (Willis), quoted and re-checked
  21. Montgomery County PY 2023 Consolidated Annual Performance and Evaluation Report, quoted and re-checked
  22. Montgomery County Flood Plain Management Regulations, quoted and re-checked
  23. Effective property tax rate: Bolthole Index county data

Written October 24, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

Answers from the rulebook for Willis

Willis’s own rules

  • Building permitRequired

    Erection, moving, addition to, or structural alteration of a building or other structure inside Willis city limits.

    • The Building Official issues the permit.
    • A permit must conform to Chapter 155 unless the Board of Adjustment provides a written administrative review, variance, or special exception.
    • Applications require an accurate plot plan and other plans necessary to demonstrate compliance.
    “No building or other structure shall be erected, moved, added to or structurally altered without a permit”
  • InspectionsLimited

    Pre-owned manufactured homes proposed for residential occupancy inside Willis city limits.

    • A pre-owned manufactured home must pass a property inspection report prepared by a licensed inspector before an occupancy permit issues.
    “All pre-owned manufactured homes must pass a property inspection report prepared by a licensed inspector before an occupancy permit will be issued.”
  • Certificate of occupancyRequired

    Occupancy, use, or change of use inside Willis city limits.

    • Required upon substantial completion for an erected or structurally altered building, a different use classification, vacant-land occupancy and use, a changed land-use classification, or a change in a conforming use.
    “Before occupancy, use or change of use, a certificate of occupancy or completion shall be required”
  • Local zoningPresent (with conditions)

    Land inside Willis city limits.

    • Land use and structures are subject to the City's zoning districts and regulations.
    “the city is divided into zoning districts, as follows:”
  • Zoning districtsPublished (with conditions)

    Zoning districts established by Willis for land inside city limits.

    • Published districts are R-1, R-2, MH, HD, GC, and GI.
    “Residential Districts: "R-1" | Single-family Residential District "R-2" | Single-family Residential District "MH" | Manufactured Home District "HD" | High Density Residential District”
  • Living in an RVLimited

    Recreation vehicles in manufactured-home parks inside Willis city limits.

    • Each recreation vehicle in a manufactured-home park must have the required permanent label and current state registration.
    • Existing recreational vehicles and recreational vehicles outside a manufactured-home park that are not occupied as a full-time residence are exempt from this requirement.
    “must maintain applicable current state registration”
  • Manufactured homesLimited

    Manufactured-home residential occupancy inside Willis city limits.

    • A Building Official-issued use and occupancy permit is required.
    • Pre-owned homes must pass a licensed-inspector property inspection before the occupancy permit issues.
    • Installation is subject to federal and state requirements under the Texas Manufactured Housing Standards Act.
    • Outside manufactured-home parks, skirting and at least 200 cubic feet of accessory storage are conditions of the permit.
    “No manufactured homes may be used or occupied as a residential dwelling within the city unless a permit for such use and occupancy has first been issued by the Building Official.”
  • Subdividing landRegulated (with conditions)

    Subdivision plans and plats inside Willis city limits.

    • The City code includes preliminary-plan, final-plat, conditional-approval, recording, variance, and replat provisions.
    “CHAPTER 154: SUBDIVISION REGULATIONS General Provisions Regulations and Requirements”
  • Permit processPublished (with conditions)

    Zoning building-permit applications inside Willis city limits.

    • Application must include an accurate, duplicate plot plan and other plans necessary to show compliance.
    • Plan dimensions for the lot's location and size must be based on an actual survey by a registered state surveyor; the lot must be staked before construction begins.
    “All applications for building permits shall be accompanied by an accurate plot plan”

Rules another office applies inside Willis

Willis does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Willis or Montgomery County directly.

  • Owner-builder exemption — Owner-builders inside Willis city limits.
  • Building code adopted — Building-code adoption for land inside Willis city limits.
  • Minimum dwelling size — Dwellings inside Willis city limits.
  • Lot coverage — Land inside Willis city limits.
  • Camping on your land — Temporary camping on land inside Willis city limits.
10 more unanswered
  • Tiny homes
  • Accessory dwellings
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Agricultural exemption
  • Driveway access
  • Short-term rentals

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Unanswered questions are usually a sign that Willis publishes no rule on the point, not that none exists. Montgomery County’s page lists the county offices to call.

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