Cities | McKinney
McKinney Multiplex Rules 2026: Backyard Cottages, Quadplexes and Small Lots
McKinney zones the land inside its city limits, so the first question for any project is the lot's district. The rules sit in the City's Unified Development Code (UDC), Chapter 150 of the Code of Ordinances, which covers zoning, subdivisions, trees, fences and stormwater. The City Council restated its zoning and subdivision articles on March 3, 2026 and changed its zoning and plat fees on October 5, 2026. This page gives the main numbers, with the section for each, and links to seven detailed pages.
McKinney in six facts
- McKinney's zoning and subdivision rules are in its Unified Development Code, adopted November 15, 2022 and last restated for zoning and subdivisions on March 3, 2026. Source: McKinney Ordinance Nos. 2026-03-027 and 2026-03-028
- A backyard cottage of up to 50 percent of the house's size is allowed in R43, R12, R8, R6, R5, R3, TR1.8 and AG. Source: McKinney UDC Sec. 205G.2.b and Table 2-26
- Duplexes, triplexes and quadplexes are permitted by right in TR1.8 and MR, and in MR a quadplex needs a 10,000 square foot lot. Source: McKinney UDC Tables 2-10 and 2-26
- Any single-family district may use the R3 lot of 3,000 square feet, 30 feet wide and 75 feet deep, for SB 15 small lots on qualifying tracts. Source: McKinney UDC Table 2-8, note 4
- Apartments are allowed with conditions in C1, C2, C3, O1 and O2 at up to 36 homes per acre, with heights of 45 to 75 feet. Source: McKinney UDC Table 2-26 and Sec. 206G.6
- Since October 5, 2026 a plat costs $325 plus $15 per lot inside the city, and a rezoning $1,000. Source: McKinney Ordinance No. 2026-10-112
McKinney Guide Pages
Where the Current Code Is
The copy of McKinney's Code of Ordinances on municode, the online code library the City uses, is labeled "Supplement 37 archive" and is codified through Ordinance No. 2022-12-145 of December 20, 2022. Its Chapter 150 page, where the UDC belongs, is empty. The City's own website answered every VanPlex request with an access error. So this guide reads the UDC from two official records. The first is the set of adopted ordinances in municode's ordinance bank: Ordinance No. 2026-03-027 restates Articles 1, 2, 4 and 9 in full, and Ordinance No. 2026-03-028 restates Article 3. The second is the "Unified Development Code_current" PDF the City attached to its February 2026 Council agenda on Legistar, the City's agenda records system, which is amended through September 16, 2025 and is used here for Articles 5 to 8.
Later changes were checked against the ordinance bank and the agenda records. Ordinance No. 2026-09-111 of September 15, 2026 capped land values for park fees in the Historic Neighborhood Improvement Zone, Ordinance No. 2026-10-112 of October 5, 2026 set new zoning and plat fees, and an October 5, 2026 ordinance changed where fence permits may be issued.
State Law in McKinney, in Brief
McKinney had 195,308 people in the 2020 Census, and the whole city lies in Collin County, which had 1,064,465. So McKinney passes the size test in the 2025 laws, by VanPlex count from 2020 Census figures. The City amended the UDC for them on September 16, 2025, and its staff presentation for that work named three "primary bills": SB 840, SB 15 and HB 24.
- SB 15 became small-lot uses in Table 2-26 and notes to the R3 and TR1.8 tables: on a single-family tract of five acres or more with no recorded plat, lots of 4,000 square feet or less may use the R3 numbers of 3,000 square feet, 30 feet wide, 75 feet deep, a 15-foot front and 10-foot rear setback, and one 9 by 20 foot parking space off the alley.
- SB 840 became apartment uses "permitted by operation of law pursuant to TLGC §218" in C1, C2, C3, O1 and O2, with Sec. 206G.6 setting 36 homes per acre, heights of 45 to 75 feet and a 25-foot setback from houses. MF30 was renamed MF36.
- HB 24 became Sec. 203D: a 60 percent protest and a majority of all Council members for rezonings that only add homes, and 20 percent and three-fourths for other changes.
Both SB 15 and SB 840 leave out land within 3,000 feet of an airport, and McKinney National Airport sits in the AP Airport district. Three parts of McKinney's text do not match the statutes, and the zoning districts page and lot size page explain each one: a specific use permit for apartments in C2, a 15-foot street-side setback on small corner lots, and a 60 percent protest rule applied to the land being rezoned.
How a Lot Reaches Two, Three or More Homes
| Homes | Where | Main rule | Code |
|---|---|---|---|
| 1 house plus a backyard cottage | R43, R12, R8, R6, R5, R3, TR1.8, AG | One per conforming lot; up to 50% of the house (75% if the house is 1,200 sq ft or less); same owner; no separate meter | Sec. 205G.2.b |
| 2 (duplex) | TR1.8, MR | MR: 5,000 sq ft lot, 35 ft tall, 14.5 homes per acre; 4 parking spaces per lot | Tables 2-9, 2-10, 2-26 |
| 3 or 4 in one building | TR1.8, MR | MR: 7,500 sq ft (triplex) or 10,000 sq ft (quadplex), 45 ft tall; 1 covered space per home off a rear alley | Tables 2-9, 2-10 |
| Townhomes | R3, TR1.8, MR | TR1.8: 1,800 sq ft lots, 24 homes per acre; meet 2 of 3 lot minimums | Table 2-9 (TR1.8) |
| Apartments | MR, MF36; C1, C2, O1 (cottage); C3, O2 (traditional) | 36 homes per acre; 1 space per home; extra design rules on commercial land | Table 2-26; Sec. 206G |
| Small lots (SB 15) | Single-family tracts of 5 acres or more with no recorded plat | R3 numbers: 3,000 sq ft, 30 ft wide, 75 ft deep; 1 space from the alley; no backyard cottage | Secs. 205D.3, 205D.4, 307A |
Source: McKinney UDC Article 2 as adopted by Ordinance No. 2026-03-027 and Article 3 as adopted by Ordinance No. 2026-03-028, March 3, 2026.
Zoning Districts
Table 2-1 sets ten residential districts: R43, R12, R8, R6, R5 and R3 for houses, TR1.8 for townhomes, MR for mixed housing, MF36 for apartments and MHR for manufactured homes. The other districts are commercial and office (C1 to C3, O1, O2), Agriculture, Airport, two industrial districts, Government Complex, McKinney Town Center and Planned Development, with three overlays on top. The 2022 code renamed older districts without moving lines; for example, SF7.2, RS 72 and RS 60 became R6. A rezoning goes to a Planning and Zoning Commission hearing and a City Council vote, needs signs on the property at least ten days before the Commission hearing, and costs $1,000. The zoning districts page has the use table and the protest rules.
Backyard Cottages and Duplexes
Sec. 205G.2.b allows one accessory dwelling unit, which "may also be referred to as a backyard cottage," on a conforming lot in eight districts. It may not exceed 50 percent of the house's square footage, or 75 percent when the house is 1,200 square feet or less, keeps the house's setbacks and height, sits behind the front of the house, stays under the same owner and has no separate electric meter. It needs one parking space if the lot does not already have four. A duplex is permitted by right in TR1.8 and MR and needs four spaces per lot. The backyard cottages and duplexes page covers both, plus sheds and home businesses.
Townhomes and Apartments
TR1.8 allows townhomes on 1,800 square foot lots at 24 homes per acre. MR gives each building type its own column: a triplex needs 7,500 square feet and a quadplex 10,000, both at 36 homes per acre and 45 feet. Triplexes and quadplexes need one covered parking space per home off a shared rear alley and no site plan. MF36 allows apartments at 36 per acre. On commercial and office land, apartments must also meet Sec. 206G.6: a ground floor of at least 14 feet built to commercial-ready standards, façade offsets, no balconies facing houses, and 75 percent covered parking. The townhomes and multifamily page has the tables.
Lots, Yards, Height and Parking
Minimum house lots run from 43,560 square feet in R43 to 3,000 in R3. A house needs four parking spaces, two of them in a garage, or two spaces in the H Historic Overlay. Front setbacks are 20 feet in R8, R6 and R5 and 15 feet in R3, and paving may cover no more than 75 percent of the required front yard. Height is measured from the average of the high and low ground points to the top of the building, or to the middle of a steep roof. The summary table in Sec. 204CC prints different heights or lot numbers from the district tables for R3, TR1.8, MF36 and MHR, so confirm which one the City applies. The lot size page and the parking, setbacks and height page have the numbers.
Historic Overlay, Airport and Flood
In the H Historic Overlay, new buildings, backyard cottages and visible exterior changes need a certificate of appropriateness, which has no fee. In the residential part of the overlay the Historic Preservation Officer may approve but not deny one. The TMN Overlay lets house lots use 80 percent of the base district's area. Chapter 118 sets height zones around McKinney National Airport, measured from the airport elevation of 582 feet, and allows any building up to 35 feet. In a floodplain, new construction is allowed only on reclaimed land, with the lowest floor at least 2 feet above the higher of the base flood or the fully developed 100-year flood. The historic overlay, airport and flood page has the details.
What the Numbers Show
McKinney had 236,001 people on July 1, 2025, by the Census Bureau's Vintage 2025 estimate, up from 195,308 in the 2020 Census. The Census Bureau's 2025 Building Permits Survey file shows McKinney reported all 12 months, with these counts:
| McKinney, 2025 permits | Buildings (homes) |
|---|---|
| 1-unit buildings | 1,649 (1,649) |
| 2-unit buildings | 0 |
| 3 to 4 unit buildings | 0 |
| 5+ unit buildings | 64 (1,391) |
Source: Census Bureau Building Permits Survey, South Region places, 2025 annual. McKinney's row shows 12 months reported, so the estimate and reported columns are the same.
The Census counts a building by the number of homes it holds, so a fourplex is one building of three to four units. The file gives counts only. It shows no two-unit buildings and no buildings of three or four units permitted in McKinney in 2025.
Plats, Permits and Fees
The City Council has delegated plat approval to the Director of Planning, who must act within the 30 days in Local Government Code 212.009. A minor plat covers four lots or fewer on an existing street, and a final plat approval lasts five years. Since October 5, 2026 a preliminary plat, final plat or replat inside the city costs $325 plus $15 per lot. A house, duplex or townhome permit costs $0.68 per square foot plus $100 plan review. New homes owe parkland of 1 acre per 37 homes or its market value, plus $1,400 per house or $1,600 per apartment. Water, wastewater and roadway impact fees are set by schedules attached to 2020 ordinances, and the City has started an update. The plats, permits and fees page has the full lists.
Where the City's Documents Disagree
VanPlex found these while reading the March 2026 text:
- Table 2-26 requires a specific use permit for traditional apartments in C2, a change made on March 3, 2026, while Local Government Code 218.101(b) bars that requirement on land zoned for commercial use.
- Sec. 203D applies the 60 percent protest rule to the land being rezoned as well as nearby land; Section 211.0061(b)(1) keeps 20 percent and a three-fourths vote for the land being rezoned, as the City's own 2025 presentation showed.
- R3 sets 15 feet on the street side of a corner lot, while Section 211.055 bars a side setback above 5 feet on an SB 15 small lot.
- Table 2-24 prints heights of 35 feet for R3 and TR1.8 and 45 feet for MF36, where the district tables print 40, 40 and 55, and it differs on TR1.8 depth and front setback and on MHR lot size.
- The code numbers two different tables 2-9, one for TR1.8 and one for parking, and repeats the numbers 2-13 to 2-15.
Where a City text conflicts with state law, the statute controls. Where two City texts conflict, Sec. 103 applies the "more restrictive or particular" one, which does not settle every case above, so ask the Planning Department in writing which one it applies to your lot.
Best For
- ✓ A house lot in R43 to R3 that meets its district minimums, for one backyard cottage.
- ✓ A lot zoned TR1.8 or MR, where a duplex, triplex or quadplex is allowed by right.
- ✓ An unplatted single-family tract of 5 acres or more, for 3,000 sq ft small lots under SB 15.
Usually Fails When
- ✕ The plan is a duplex or fourplex on R43 to R3 land without a rezoning.
- ✕ The site is within 3,000 feet of McKinney National Airport and the plan relies on SB 15 or SB 840.
- ✕ The plan puts a backyard cottage on an SB 15 small lot.
What To Verify Before Spending Money
- → The district, any Planned Development ordinance and any overlay on the Official Zoning Map.
- → The FEMA and fully developed flood levels for the lot.
- → Recorded deed restrictions and HOA rules for the subdivision.
Where to Go Next
Related on VanPlex: the how Texas zoning works page, financing 2 to 4 units and the Texas multiplex guide overview.
Frequently Asked Questions
What are the rules for building more than one home on a lot in McKinney?
How many people live in McKinney?
How many homes did McKinney permit in 2025?
Did McKinney change its code for the 2025 Texas housing laws?
Which county is McKinney in?
Is the McKinney zoning code on municode?
Can I build a triplex on an R6 lot in McKinney?
Do HOA rules still apply when building in McKinney?
Who approves plats and apartment site plans in McKinney?
Where does McKinney list its development fees?
Official sources (checked October 2026)
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