Building permits, zoning and land rules in Katy, Texas

At a glance

Building permits

City building permits required for most construction and improvements¹

Zoning

Katy has city zoning; identify the parcel’s district²⁵

RV living

Temporary and permanent occupancy prohibited in the listed residential, commercial and manufacturing districts⁶

Minimum home size

R-1 dwellings: at least 1,200 square feet, excluding basements, porches and garages⁷

Setbacks

R-1 interior lots: front setback of 25 feet on minor streets or 35 feet on major streets; specified side setback of 7.5 feet⁸

Septic

Texas generally requires a septic permit and approved plan; confirm the parcel’s local permitting authority⁹

Who to call

Contact details are copied from each office’s official page and were checked against it on October 11, 2026.

Do you need a building permit in Katy, Texas?

Katy requires a building permit for most construction and property improvements, including a new home, remodeling, roofing, heating and air-conditioning installation or replacement, and electrical and plumbing work.¹ The City of Katy Permit and Building Services Division administers building permits, coordinates plan review and provides inspections.¹ Katy reports adoption of the 2021 International Building Codes and the 2023 National Electrical Code.¹ Ask the city division to identify the application and inspection requirements for your proposed work before arranging construction.¹

Who handles Katy building permits and building permit searches?

The City of Katy Permit and Building Services Division is the building-permit counter for construction inside Katy, with plan review and inspection services handled by the city.¹ Contact the division using the verified contact details below, and use the Civic Access link on its department page for online building-permit applications, electronic plans, invoice payments and project tracking.¹ Anyone may search public records through Civic Access without contractor or homeowner registration, but public searches show limited information.¹ Katy also directs inspection scheduling through Civic Access.¹

Does Katy have zoning, minimum home sizes and setbacks?

Katy has city zoning, including an R-1 single-family district and an MH mobile-home district; the parcel’s district determines which dimensional and use rules apply.²⁵ In Katy’s R-1 district, a dwelling must have at least 1,200 square feet of floor area, excluding basements, open and screened porches, and garages.⁷ For R-1 interior lots, the front setback is 25 feet on minor streets and 35 feet on major streets, with 7.5-foot side setbacks on interior single-family lots facing minor and secondary streets; corner-lot requirements vary.⁸ R-1 main buildings may not exceed 35 feet or 2.5 stories.¹⁰ Ask City Planning to identify the parcel’s zoning district before designing the home.¹¹

Can you live in an RV or tiny home in Katy?

Katy prohibits temporary or permanent occupancy of travel trailers, campers and recreational vehicles in R-1, R-2, R-3, C-1, C-2 and M districts.⁶ The separate mobile-home-park provision limits travel trailers and RVs used as temporary living quarters to 10 days unless the building inspector gives special permission; that provision is specific to mobile-home parks.¹² We could not confirm a general tiny-home occupancy rule for Katy; ask City Planning about the proposed structure and district.¹¹ An R-1 dwelling must still satisfy the district’s 1,200-square-foot minimum.⁷ Katy also prohibits placing a manufactured home on a lot where residential improvements already exist.¹³

How do septic permits work inside Katy?

Texas generally requires a septic permit and approved plan to construct, alter, repair, extend or operate an on-site sewage facility, and local requirements may be stricter than state minimums.⁹ For land on the Waller County side of Katy, contact the Waller County Environmental Division before installing a private septic system and ask the division to confirm the parcel’s permitting jurisdiction.⁴ We could not confirm a single septic authority applicable to every parcel inside Katy; ask the city building division to confirm the address’s wastewater arrangements.¹ Texas’s 10-acre exemption is conditional, requiring a site evaluation, a single dwelling, on-site disposal, no nuisance or groundwater pollution, and all system parts at least 100 feet from property lines, alongside the other state standards.⁹ Mobile homes in Katy mobile-home parks must connect to approved water and sanitary sewer systems.¹⁴

What are the steps before building a home in Katy?

Start with City Planning: identify the zoning district and ask whether the proposed home fits the permitted use and site dimensions.¹¹² For an R-1 parcel, design around the minimum dwelling size and applicable setbacks before submitting building plans.⁷⁸ Next, contact the city building division about the building-permit application and plan review, then use its Civic Access site to submit plans and track the application.¹ If septic is proposed, establish the local permitting authority and obtain the required septic approvals before installation.⁹ Schedule city building inspections through Civic Access as construction proceeds.¹ For land outside Katy city limits, see the Waller County guide for the county’s residential development requirements.¹⁵

Watch-outs

• Katy’s mobile-home-park temporary-stay provision does not establish permission to live in an RV on an ordinary residential lot.¹²⁶
• We could not confirm Katy-wide well requirements or an owner-builder exemption; ask the city building division about the specific project before relying on either.¹

Sources

1. City of Katy Permit and Building Services Division (cityofkaty.com)
2. § 6. R-1 Single-Family District (Katy), quoted and re-checked
3. Certificate of Occupancy and Zoning within Unincorporated Areas of Waller County, quoted and re-checked
4. Waller County Environmental Division (co.waller.tx.us)
5. § 6. R-1 Single-Family District (Katy), quoted and re-checked
6. § 13.3 Mobile-home and recreational-vehicle restrictions (Katy), quoted and re-checked
7. § 6. R-1 Single-Family District (Katy), quoted and re-checked
8. § 6. R-1 Single-Family District (Katy), quoted and re-checked
9. Getting a Permit for an OSSF - Such as a Septic System (Texas statewide rule), quoted and re-checked
10. library.municode.com (Katy), quoted and re-checked
11. City of Katy Planning (cityofkaty.com)
12. § 3.05.043 Park administration and operation; installation requirements (Katy), quoted and re-checked
13. § 3.05.004 Placement of manufactured home on lot with existing residential use prohibited (Katy), quoted and re-checked
14. § 3.05.043 Park administration and operation; installation requirements (Katy), quoted and re-checked
15. Certificate of Occupancy and Zoning within Unincorporated Areas of Waller County, quoted and re-checked

Written October 11, 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.