McKinney | Lot Size and Small Lots
McKinney Lot Size and Small Lots: District Minimums, Conflicting Tables and SB 15
In McKinney the zoning district sets the smallest lot you can create, and Article 3 of the Unified Development Code (UDC) sets how lots are drawn on a plat, the recorded map that divides land into lots. Both articles were restated on March 3, 2026. This page gives the lot numbers for each district, the places where two tables in the code disagree, and the City's rules for SB 15 small lots. The McKinney overview gives the short version.
McKinney lot rules in six facts
- The smallest lot for a house is 43,560 square feet in R43, 12,000 in R12, 8,000 in R8, 6,000 in R6, 5,000 in R5 and 3,000 in R3. Source: McKinney UDC Tables 2-3 to 2-8
- A TR1.8 townhome lot needs 1,800 square feet, 22 feet of width and 75 feet of depth, and only two of those three numbers must be met. Source: McKinney UDC Table 2-9 (TR1.8)
- Any lot in a single-family district may use the R3 dimensions when it is platted as an SB 15 small lot and the plat says so. Source: McKinney UDC Table 2-8, note 4
- A small lot is one of 4,000 square feet or less, under both state law and the McKinney definitions. Source: Local Government Code 211.051 and UDC Sec. 205D.4
- Lots narrower than 50 feet in R5, R3 and TR1.8 must take access from an alley along the rear of the lot. Source: McKinney UDC Tables 2-7 to 2-9
- The district tables and the summary table in Sec. 204CC print different numbers for R3, TR1.8, MF36 and MHR. Source: McKinney UDC Table 2-24
Minimum Lots by District
Each residential district in Sec. 204 has a table of lot dimensions. Lot area is the land inside the property lines. Lot width is measured across the lot and lot depth from front to back. The R43 district's purpose statement ties its number to "lots of at least one acre (43,560 square feet)."
| District | Lot area (sq ft) | Width (ft) | Depth (ft) | Table |
|---|---|---|---|---|
| R43 | 43,560 | 150 | 150 | Table 2-3 |
| R12 | 12,000 | 80 | 120 | Table 2-4 |
| R8 | 8,000 | 60 | 100 | Table 2-5 |
| R6 | 6,000 | 50 | 90 | Table 2-6 |
| R5 | 5,000 | 40 (alley access under 50) | 80 | Table 2-7 |
| R3 | 3,000 | 30 (alley access under 50) | 75 | Table 2-8 |
| TR1.8 | 1,800 | 22 (alley access under 50) | 75 (80 in Table 2-24) | Table 2-9; meet 2 of 3 |
| MR, house | 5,000 | 50 | 100 | Table 2-10 |
| MR, townhome | 1,800 | 22 | 80 | Table 2-10 |
| MF36 | None | 60 | 100 | Table 2-11 |
| MHR | None (4,500 in Table 2-24) | 60 (40 in Table 2-24) | 100 (95 in Table 2-24) | Table 2-12 |
Source: McKinney UDC Secs. 204D to 204M and Table 2-24, as adopted by Ordinance No. 2026-03-027, March 3, 2026.
The MR Mixed Residential district sets lot sizes by building type. A duplex needs 5,000 square feet, a triplex 7,500 and a quadplex 10,000, each 50 feet wide and 100 feet deep. Cottage and traditional apartment sites have no minimum area and need 60 feet of width and 100 of depth. The townhomes and multifamily page has the full MR table.
Narrow lots carry an access rule. Notes to the R5, R3 and TR1.8 tables say "Lots less than 50 feet in width shall be accessed via alleys abutting the rear of the lot." An alley is a narrow public way along the backs of lots. Note 4 to Table 2-24 adds that detached houses built in TR1.8 follow the R5 standards. In the TMN Traditional McKinney Neighborhood Overlay, a house lot may be 80 percent of the base district's area and 90 percent of its width and depth (Table 2-23). The historic overlay page covers the TMN.
Two Tables That Disagree
Sec. 204CC repeats the district numbers in a summary, Table 2-24. For four districts the summary does not match the district's own table, and both tables were adopted on the same day:
- R3: Table 2-8 sets a height of 40 feet; Table 2-24 sets 35.
- TR1.8: Table 2-9 sets a 15-foot front setback, a 75-foot lot depth and a 40-foot height; Table 2-24 sets 20 feet, 80 feet and 35 feet. Table 2-24 also cites Sec. 204I for TR1.8, the section for R3.
- MF36: Table 2-11 sets a height of 55 feet; Table 2-24 sets 45.
- MHR: Table 2-12 sets no minimum lot area, a 60-foot width and a 100-foot depth; Table 2-24 sets 4,500 square feet, 40 feet and 95 feet.
Sec. 204B.2 settles conflicts between drawings and tables only. The general rule in Sec. 103 says that "the provision that is more restrictive or particular shall govern." The district tables are the more particular text and the summary is the more restrictive one, so that rule does not settle these four cases. Before you design to the higher number, ask the Planning Department in writing which table it applies.
What SB 15 Says
SB 15 added Sections 211.051 to 211.058 to the Local Government Code, in force since September 1, 2025. McKinney had 195,308 people in the 2020 Census and sits in Collin County, which had 1,064,465, so it is a covered city by VanPlex count. The law reaches only a tract that will be platted, is "located in an area zoned for single-family homes," "is five acres or more," and "has no recorded plat" (Section 211.052). Land within 3,000 feet of an airport or military base is left out.
On such a tract the city may not require a lot larger than 3,000 square feet, wider than 30 feet or deeper than 75 feet (Section 211.054). For a "small lot," which Section 211.051 defines as a residential lot of "4,000 square feet or less," Section 211.055 bars setbacks greater than 15 feet in front, 10 in back and 5 on the side, covered parking, more than one space per unit, off-site parking, more than 30 percent open space, and fewer than "three full stories not exceeding 10 feet in height measured from the interior floor to ceiling." The city may still require a shared driveway, the normal single-family permit fees and impact fees.
How McKinney Applies SB 15
McKinney wrote its small-lot rules into the code in September 2025 and kept them in the March 2026 text. Table 2-26 permits small-lot detached homes with conditions in R43, R12, R8, R6, R5, R3 and TR1.8, and small-lot attached homes in R3 and TR1.8. Sec. 205D.4 defines a small-lot detached home as one "situated on a lot that is 4,000 square feet or less." The conditions for both types are the same:
- the use "is permitted by operation of law" under chapter 211, Subchapter D, and only on land that meets Section 211.052;
- a lot over 4,000 square feet, or a lot on a cul-de-sac or corner, may count as a small lot when each lot beside it is also a small lot, or when most lots on its block are;
- the plat and its setback exhibit must carry a note naming the use; and
- the lot "shall be required to meet the minimum standards of R3."
Note 4 to Table 2-8 says any lot in a single-family district "may use the dimensional standards of the R3 zoning district" when it is "platted as a 'small lot' with dimensions allowed under TLGC §211.052." Sec. 307A.1.a.I in Article 3 says the same thing for subdivisions, "irrespective of the normal standards for the residential zoning district wherein it resides." Each preliminary plat and final plat for small lots must carry this note: "All proposed lots meet the applicability requirements outlined in §211.052 of the TLGC and may be developed as a small lot single-family residential use."
| Rule | State law (Sections 211.054, 211.055) | McKinney R3 and small-lot notes | Fit |
|---|---|---|---|
| Lot area | No more than 3,000 sq ft may be required | 3,000 sq ft (R3) | Matches |
| Lot width and depth | No more than 30 ft wide and 75 ft deep | 30 ft and 75 ft (R3) | Matches |
| Front and rear setback | No more than 15 ft front, 10 ft rear | 15 ft front, 10 ft rear | Matches |
| Side setback | No more than 5 ft from the side | 5 ft interior side; 15 ft on the street side of a corner lot | Corner side is larger than state law allows |
| Parking | No more than 1 space per unit; no covered or off-site parking | One 9 by 20 ft space on site, reached from the alley | Matches |
| Height | At least three full stories of up to 10 ft each | 40 ft in Table 2-8; 35 ft in Table 2-24 | Code gives no story count; ask the City |
Source: Local Government Code 211.054 and 211.055; McKinney UDC Table 2-8 and its notes, Table 2-9 (parking), Table 2-24 and Sec. 205D.3 and 205D.4, Ordinance No. 2026-03-027.
Two rows need care. R3 sets 15 feet on the street side of a corner lot, and Section 211.055(a)(1)(B) bars a setback "greater than ... five feet from the side of the property" on a small lot. The statute has no corner exception, and where the code and the statute conflict, the statute controls. On height, the code states feet and the statute states stories, so ask the City how it applies the three-story rule on a small lot.
The alley rule is a third question. A lot under 50 feet wide in R3 must take access from a rear alley, and the City's 2025 staff presentation on SB 15 repeated it: "Lots less than 50 feet require rear access via alleys." Section 211.055(b) lists a shared driveway as something a city may require and does not mention alleys. Ask the Planning Department how it applies the alley rule to a small lot before you lay out the plat.
Two more city rules attach to small lots. Accessory dwelling units are barred on them (Sec. 205G.2.b), and Table 2-30 asks for one canopy tree on a lot of 4,000 square feet or less. Section 211.057 says the state law does not stop property owners from enforcing deed restrictions or homeowners' association rules.
Lot Design Rules for Any Plat
Sec. 307A of Article 3 sets rules for every new lot, on top of the district minimums:
- Shape. "Lots shall be rectangular insofar as is practical," sharp angles are to be avoided, and the depth to width ratio "shall not ordinarily exceed 2.5 to 1."
- Frontage. Every lot needs frontage on an existing or proposed public street, or on a private street in an approved private street development.
- Front and back. Single-family, duplex, triplex and quadplex lots "shall not front and back to a street." A house lot may back to an alley or to another lot.
- Creeks. A lot backing onto a natural drainage area needs a usable depth of at least 80 feet, measured from the front property line to the edge of the drainage area or easement.
- Septic systems. On-site sewage facilities are allowed only on lots of 1.5 acres or more, with at least 1 acre of net developable area, when there is no feasible way to provide sewer service and the Director of Engineering approves.
- Water wells. "Water wells shall not be used for domestic water service."
Where a plat sets a setback, that setback "shall prevail over any setback prescribed by the governing zoning" (Sec. 204DD.2.a). So a recorded plat line can be stricter or looser than the district table.
Building on a Lot That Is Not Platted
Sec. 202B lists the ways a building site can exist for a permit. The lot can be part of a recorded plat, part of an approved site plan for apartments or commercial use, or a lot that "faces upon a dedicated paved public right-of-way" and "existed prior to April 29, 1968, or prior to the annexation of the property into the city." In that last case "only one building permit for a single main building" may be issued on the lot.
Ordinance No. 2026-03-028, also of March 3, 2026, put back a related rule in Sec. 301C.2.b: a building permit "may be issued for one single family building on an unplatted plot, tract, or lot that faces a dedicated street" and was separately owned in that shape before the subdivision ordinance or annexation. The City's presentation for that change, agenda item 26-0002M, listed it as a change to "Reintroduce" the rule. Most divisions of land need a plat; the plats, permits and fees page covers the plat types.
Best For
- ✓ An unplatted single-family tract of five acres or more, more than 3,000 feet from an airport, for R3-size small lots.
- ✓ A TR1.8 townhome lot that meets two of the three minimums of 1,800 sq ft, 22 ft and 75 ft.
- ✓ An R5 or R3 subdivision with rear alleys, where lots under 50 ft wide are allowed.
Usually Fails When
- ✕ The plan splits an existing platted lot in an older neighborhood under SB 15.
- ✕ A small lot design counts on a backyard cottage.
- ✕ A narrow lot has no rear alley.
What To Verify Before Spending Money
- → Which table the City applies where Table 2-24 and the district table differ.
- → Whether the tract is five acres or more, unplatted, and outside 3,000 feet of McKinney National Airport.
- → Setbacks printed on any recorded plat, which prevail over the district table.
Where to Go Next
Related on VanPlex: the McKinney overview, the SB 15 small lots page, and how Texas zoning works.
Frequently Asked Questions
What is the minimum lot size for a house in McKinney?
Can I split my McKinney lot into small lots under SB 15?
What setbacks apply to a small lot in McKinney?
How much parking does a McKinney small lot need?
Can I build a backyard cottage on a small lot in McKinney?
Why do two McKinney tables show different lot rules?
What is the TR1.8 two-of-three rule in McKinney?
Can I get a building permit on an unplatted McKinney lot?
How deep must a McKinney lot be when it backs onto a creek?
How many trees must a new McKinney house lot have?
Official sources (checked October 2026)
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