Bolthole Index

Collin County, Texas

Zoning, building permits and septic rules in McKinney, Texas

McKinney, Texas, in Collin County, has its own zoning rules, published as Article 2 of the city's Unified Development Code1. Building permits for projects inside McKinney go through the city's online Citizen Self-Service Portal2. We could not confirm who issues septic permits inside city limits, so ask before you plan a septic system on a McKinney lot3.

At a glance

Zoning
Yes, the city zones land inside McKinney limits (UDC Article 2)1
Building permit
Required for accessory dwelling units; apply through the Citizen Self-Service Portal4
Inspections
Scheduled through the same portal5
Accessory dwellings
Allowed on single-family zoned lots, subject to zoning and HOA rules6
Subdivision
Regulated by Article 3 of the city's code7
Septic
Unconfirmed inside city limits; Collin County handles it outside city limits8

Who to call

Planning & zoning

City of McKinney Planning Department

Zoning questions and the Unified Development Code for land inside McKinney city limits

972-547-2000

401 E. Virginia St. McKinney, TX 75069

Septic permits

Collin County Development Services (On-Site Sewage Facilities / OSSF Program)

Septic permits for property outside city limits; call to learn who handles an address inside city limits

(972) 548-5585

4690 Community Ave., McKinney, Texas, 75071

Online permits →

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 McKinney means bringing your own water and power. The kit we’d start with:

These are affiliate links — we may earn a commission, at no cost to you. As an Amazon Associate, Bolthole Index earns from qualifying purchases.

Does McKinney, Texas have zoning?

Yes. The City of McKinney publishes zoning rules as Article 2, "Zoning Regulations," of its Unified Development Code, and those rules apply to land inside McKinney city limits19. Zoning districts are published in that article, so the rules for your lot depend on which district it sits in10.

This is different from unincorporated Collin County, which has no countywide zoning apart from a few listed business types11. Do not assume county freedoms apply inside McKinney.

We could not confirm McKinney's rules on RV living, tiny homes, manufactured homes, minimum lot size or minimum home size from the city's published pages. Ask the Planning Department at 972-547-2000 for your parcel's district before you buy9.

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

The City of McKinney issues building permits for work inside city limits. For an accessory dwelling unit, the city's guide tells applicants to submit through the Citizen Self-Service Portal4. City staff review plans, fees are paid after approval, and construction begins after the permit is issued2.

Inspections are also booked through the portal5. We could not confirm which building-code editions McKinney currently enforces, when a certificate of occupancy is required, or whether the city offers an owner-builder exemption, so confirm those with the city before you start.

The county's permit rules apply to unincorporated Collin County, not to land inside McKinney12.

Can you build an accessory dwelling unit in McKinney?

Often yes. McKinney allows an accessory dwelling unit when the property is zoned for a single-family residential home and has enough space to meet building regulations6. Planned Development zones may not allow one, and an HOA can add restrictions6.

Setbacks for an accessory dwelling unit follow the main home's setbacks and vary by zoning district13. The unit cannot be taller than the main house: a one-story house limits it to one story, and a two-story house lets it match but not exceed that height14.

How do septic permits work in McKinney?

We could not confirm who administers septic permits inside McKinney city limits, or what the city requires for septic inspections, wells or off-grid sanitation. Collin County applies state septic rules plus a stricter county order, and its septic page says another authorized agent may administer septic permitting inside city limits8.

For property outside city limits, the county requires a septic permit through its Citizen Self-Service Portal3. If your lot is inside McKinney, call Collin County Development Services at (972) 548-5585 and the City of McKinney Planning Department at 972-547-2000 to learn which office permits septic at your address39. Texas requires a permit to build or alter a septic system15.

Building a home in McKinney: the steps, in order

  1. Confirm the lot is inside city limits, then ask the Planning Department which zoning district applies9.
  2. Read the zoning and subdivision articles of the Unified Development Code; Article 3 covers dividing land7.
  3. Apply for your building permit through the Citizen Self-Service Portal4.
  4. Wait for staff review, then pay fees after approval2.
  5. Book inspections through the portal during construction5.
  6. If the lot needs septic, confirm the permitting office first8.

What stays with Collin County, and what to check before you buy

Land outside McKinney city limits falls under Collin County, whose rules differ from the city's. In unincorporated Collin County, a permit is required for projects that disturb ground or add footprint12. Septic permits there come from the county8.

For cost context, Collin County's typical home value is $486,57016 and its effective property tax rate is 1.7%17. Only 1% of the county's soils are rated not limited for a conventional septic drain field, so expect a site evaluation and possibly an engineered system18. Check floodplain status and any HOA rules with the city and the seller before you close.

Watch-outs

  • We could not confirm McKinney's rules on RV or tiny-home living, so ask the Planning Department before you place either on a lot9.
  • We could not confirm who permits septic systems and private wells inside McKinney city limits; confirm before you rely on either8.
  • Planned Development zones may not allow an accessory dwelling unit, and HOA rules can add limits6.

Sources

  1. Unified Development Code | McKinney, TX - Official Website (McKinney), quoted and re-checked
  2. Building an Accessory Dwelling Unit in McKinney Guide (McKinney), quoted and re-checked
  3. Collin County Development Services (On-Site Sewage Facilities / OSSF Program) (collincountytx.gov)
  4. Building an Accessory Dwelling Unit in McKinney Guide (McKinney), quoted and re-checked
  5. Building an Accessory Dwelling Unit in McKinney Guide (McKinney), quoted and re-checked
  6. Building an Accessory Dwelling Unit in McKinney Guide (McKinney), quoted and re-checked
  7. Unified Development Code | McKinney, TX - Official Website (McKinney), quoted and re-checked
  8. Development Services: On Site Sewage Facilities, quoted and re-checked
  9. City of McKinney Planning Department (mckinneytexas.org)
  10. Unified Development Code | McKinney, TX - Official Website (McKinney), quoted and re-checked
  11. collincountytx.gov, quoted and re-checked
  12. collincountytx.gov, quoted and re-checked
  13. Building an Accessory Dwelling Unit in McKinney Guide (McKinney), quoted and re-checked
  14. Building an Accessory Dwelling Unit in McKinney Guide (McKinney), quoted and re-checked
  15. Getting a Permit for an OSSF - Such as a Septic System (Texas statewide rule), quoted and re-checked
  16. Typical home value (Zillow): Bolthole Index county data
  17. Effective property tax rate: Bolthole Index county data
  18. 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

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 McKinney

McKinney’s own rules

  • Building permitRequired

    Accessory dwelling unit construction inside McKinney city limits.

    • The City guide directs applicants to submit through the Citizen Self-Service Portal; City staff review plans, fees are paid after approval, and construction begins after receipt of the permit.
    “Apply for your building permit • Submit your application through the CSS Portal.”
  • InspectionsRequired

    Accessory dwelling unit construction inside McKinney city limits.

    • The guide directs the applicant to schedule inspections through the City Citizen Self-Service Portal.
    “Schedule Inspections • Book your inspections through the CSS Portal.”
  • Local zoningPresent (with conditions)

    Land inside McKinney city limits.

    • The City’s current development regulations include a separately published Article 2, "Zoning Regulations."
    “Development Regulations (Current) [...] Article 2: Zoning Regulations - PDF”
  • Zoning districtsPublished (with conditions)

    Zoning districts inside McKinney city limits.

    • The City’s current UDC webpage publishes Article 2, "Zoning Regulations."
    “Development Regulations (Current) [...] Article 2: Zoning Regulations - PDF”
  • SetbacksDistrict specific (with conditions)

    Accessory dwelling units inside McKinney city limits.

    • The guide states that the ADU follows the same setback rules as the main home and that the result varies by zoning district.
    “Same setback rules as your main home. • Varies depending on your zoning district.”
  • Building heightSpecified

    Accessory dwelling units inside McKinney city limits.

    • An ADU may not exceed the primary house height; a one-story primary house limits the ADU to one story, while a two-story primary house allows an ADU to match but not exceed it.
    “Your ADU can't be taller than your main house. • If your home is one story, your ADU must be one story. • If your home has two stories, the ADU can match but not exceed it.”
  • Accessory dwellingsAllowed (with conditions)

    Accessory dwelling units on lots inside McKinney city limits.

    • The property must be zoned for a single-family residential home and have enough space to meet building regulations.
    • Planned Development zones may not allow an ADU.
    • HOA rules may impose additional restrictions.
    “You can build an ADU if your property is zoned for a single-family residential home and has enough space to meet building regulations.”
  • Subdividing landRegulated (with conditions)

    Subdivision of land inside McKinney city limits.

    • The City publishes Article 3, "Subdivision Regulations," within its current Unified Development Code.
    “Development Regulations (Current) [...] Article 3: Subdivision Regulations - PDF”
  • Permit processPublished (with conditions)

    Accessory dwelling unit projects inside McKinney city limits.

    • Applications go through the City Citizen Self-Service Portal; applicants submit plans, undergo staff review, pay fees after approval, receive the permit, and schedule inspections.
    “Building an ADU in McKinney involves a few key steps. All applications go through the Citizen Self-Service (CSS) Portal, your one-stop shop for permits and inspection requests.”

Still unanswered

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

  • Owner-builder exemption — Owner-built residences inside McKinney city limits.
  • Building code adopted — Building construction inside McKinney city limits.
  • Certificate of occupancy — Buildings and occupancy inside McKinney city limits.
  • Minimum dwelling size — Principal dwellings inside McKinney city limits.
  • Minimum lot size — Residential lots inside McKinney city limits.
15 more unanswered
  • Lot coverage
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Driveway access
  • Building in a floodplain
  • 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 McKinney publishes no rule on the point, not that none exists. Collin County’s page lists the county offices to call.

← All of Collin County: county rules, score and offices