How McKinney Handles Accessory Structures: A Practical Guide

McKinney maintains 124 local ordinances across all categories, and 9 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where McKinney falls on the strict-to-permissive spectrum compared to other cities.

Tiny Homes

Tiny homes on wheels (THOWs) treated as RVs in McKinney and cannot be used as permanent dwellings on single-family lots. Tiny homes on foundations must meet standard zoning minimum floor area, typically 1,000 sq ft or larger depending on district.

Key details: THOW: Treated as RV. Foundation: Must meet min floor area. Min Size: District-specific. RV Parks: Only licensed sites.

Illegal occupancy: up to 2,000 dollars per day plus removal order. RV as dwelling on SF lot prohibited.

Compared to other cities, McKinney takes a harder line on tiny homes. The enforcement and penalty structure reflects that.

Carport Rules

McKinney permits attached carports on residential lots subject to setbacks and building permit. Front-yard prefabricated metal carports generally prohibited in most single-family zoning districts.

Key details: Front Setback: 25 ft. Side Setback: 5 ft attached. Front-Yard Metal: Generally banned. Enclosure Limit: 40 percent.

Unpermitted or noncompliant carports: up to 500 dollars per day plus removal order.

ADU Permits

McKinney restricts accessory dwelling units in single-family residential districts. Under the McKinney Zoning Ordinance, an accessory living quarters or guest house may be permitted as incidental to the principal dwelling but cannot be rented as a separate household. Establishing a true ADU as a separate rental unit typically requires a Specific Use Permit (SUP), reviewed by the Planning & Zoning Commission and City Council under Texas Local Government Code Ch. 211 zoning authority.

Key details: Authority: McKinney Zoning Ord; TX LGC Ch. 211. Accessory Use: Guest house/servant's quarters. Separate Rental ADU: Requires SUP. HPO Districts: Certificate of Appropriateness. Building Code: 2021 IRC with TX amendments.

Building an unpermitted second dwelling unit: stop-work order from Building Inspections, daily fines up to $2,000 per violation for building code violations and $500 per day for zoning violations under Texas Local Government Code §54.001, and Code Services citations. Operating an unpermitted second unit as a rental violates McKinney's single-family district zoning. Unpermitted work in the HPO can trigger additional restoration orders.

Compared to other cities, McKinney takes a harder line on adu permits. The enforcement and penalty structure reflects that.

ADU Owner Occupancy

McKinney's single-family residential zoning effectively requires owner-occupancy by limiting each lot to one dwelling unit. The accessory guest house cannot be rented as a separate household. Where a Specific Use Permit allows a true second unit, owner-occupancy is typically a recorded SUP condition. Texas has not preempted local owner-occupancy conditions.

Key details: Effective Requirement: Yes - one unit per lot. Authority: McKinney RS zoning districts. Where SUP Granted: Owner-occupancy typically required. Deed Restriction: Recorded with Collin County Clerk. Both Units Rented: Prohibited in SF districts.

Renting an unauthorized second dwelling unit: zoning violation under the McKinney Zoning Ordinance, fines up to $500 per day under Texas Local Government Code §54.001, possible Code Services enforcement action including injunction. False statement on an owner-occupancy affidavit: Class B misdemeanor under Texas Penal Code §37.10.

This is not one of those rules that cities tend to ignore. McKinney actively enforces its adu owner occupancy requirements.

ADU Impact Fees

McKinney charges standard impact and utility fees on new dwelling units under Texas Local Government Code Chapter 395 authority, including water/wastewater impact fees and roadway impact fees in adopted service areas. There is no Texas statewide ADU impact-fee waiver comparable to California Gov. Code §65852.2(f). Costs depend on whether the unit requires a new utility connection.

Key details: Authority: TX LGC Ch. 395 Impact Fees. Water Impact: Per adopted CIP - SFE basis. Wastewater Impact: Per adopted CIP - SFE basis. Roadway Impact: Applies in service areas. Share Existing Tap: Avoids most impact fees.

Failure to pay impact fees: permit denial or revocation, lien against the property for unpaid fees. Building without paying connection fees: McKinney Water Utilities disconnection authority and possible Code Services citation. After-the-fact permits often incur double fees.

ADU Rental Restrictions

McKinney's single-family zoning prohibits renting an accessory guest house as a separate household. Where an SUP permits a true second unit, long-term (30+ days) rental is allowed if owner-occupancy continues. Short-term rentals (under 30 days) are subject to McKinney's short-term rental regulations and Hotel Occupancy Tax. Texas SB 987 (2023) was vetoed; STR preemption remains unresolved.

Key details: SF Zoning: No separate rental household. Long-Term (30+ days): OK if SUP + owner-occupied. STR Threshold: <30 days. Hotel Occupancy Tax: State 6% + McKinney 7%. Rent Control: Preempted by TX LGC §214.902.

Renting an unauthorized accessory unit: McKinney Zoning Ordinance violation, fines up to $500 per day under TX LGC §54.001, possible Code Services citation and injunction. Unregistered STR: McKinney STR ordinance violation. Failure to remit Hotel Occupancy Tax: Texas Comptroller and McKinney enforcement under TX Tax Code Ch. 156 and 351.

This is not one of those rules that cities tend to ignore. McKinney actively enforces its adu rental restrictions requirements.

ADU Rules

McKinney generally does not permit accessory dwelling units (ADUs) as-of-right in single-family zoning districts. Guest quarters without cooking facilities allowed under Zoning Chapter 146 accessory use rules.

Key details: By-Right: No in SF districts. Guest Quarters: No second kitchen. SUP Path: Some districts. State Preemption: None yet.

Illegal ADU rental: up to 2,000 dollars per day plus order to cease use.

This is not one of those rules that cities tend to ignore. McKinney actively enforces its adu rules requirements.

Shed Rules

McKinney sheds 200 square feet or smaller and under 8 ft tall do not require a building permit but must meet zoning setbacks (typically 3 ft side and rear). Larger sheds require permit.

Key details: Permit Exempt: Under 200 sq ft and 8 ft. Setback: 3 ft typical. Easement: Prohibited without consent. Containers: Not allowed.

Unpermitted large shed or setback violation: up to 500 dollars per day plus removal order.

Garage Conversions

Garage conversions in McKinney require building permit, zoning verification, and replacement of required off-street parking. Conversions that create separate dwelling units are not allowed in SF districts.

Key details: Parking: 2 covered required. Replacement: Must be built. Separate Unit: Not allowed. Egress: Windows required.

Unpermitted conversion: up to 2,000 dollars per day plus order to restore. Appraisal district also reassesses.

This is one of the stricter rules in McKinney's municipal code. If you are unsure whether your situation complies, it is worth checking with the city before proceeding.

The Bottom Line

McKinney is tougher than many cities when it comes to accessory structures. Out of the 9 rules covered here, 6 are rated strict. If you are a homeowner, renter, or business owner in McKinney, take the time to understand these requirements before they become a problem. Most violations come with fines, and some repeat violations can escalate.

This guide is based on McKinney's current municipal code. Local rules can and do change, so check the individual ordinance pages for the latest details, penalties, and FAQs.