Side by side · Texas
Compare ADU rules across Texas
Flexible on where you build? The same backyard cottage can be routine in one city and impossible next door. This table puts 29 Texas cities side by side so you can shortlist the friendly ones before reading a single ordinance, or narrow it to just the cities you are deciding between. Every value is summarized from the city's own code; open a city's page for the full notes, citations, and fine print.
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| City | Detached ADU | Attached / internal | Max size | Owner occupancy | Extra parking | Approval |
|---|---|---|---|---|---|---|
| Amarillo | Not allowed | Not allowed | No square-footage cap stated for a servants/caretakers quarters or residential accessory buildings; size is governed by district bulk limits: maximum lot coverage 45 percent in R-1 and R-2, 65 percent in R-3, MD, and MF districts, maximum height 2 stories in R and MD districts, and accessory buildings larger than 200 sq ft need a 3 ft side yard and a 10 ft rear yard where no alley exists. | Not required | 2 off-street spaces per dwelling unit for single-family detached homes in the A, R, and MD districts; no separate parking figure is stated for a servants/caretakers quarters, and total parking is computed as the sum of the requirements for each use on the lot. | Where the Schedule of Uses shows a permitted square, a servants or caretakers quarters is a by-right use needing only building permits: A, MD-2, MF-1, MF-2, O-1, O-2, NS, GR, LC, CB, HC, I-1, and I-2 (and PD per its site plan). The use carries no 'S' designation in any district, so there is no specific-use-permit path where it is prohibited; in R-1, R-2, R-3, MD-1, and MH the only route to a secondary unit would be rezoning. Ordinance read July 2026 |
| Arlington | Arlington's ADU analog is the 'secondary living unit': a second single-family living unit on the same lot with its own living/sleeping, cooking, and sanitation, which may be detached. Per use Table 3.3-1 it is permitted with supplemental standards (P*) in the RE, RS-20, RS-15, and VG districts, but needs a Specific Use Permit in RS-7.2, RS-5, and RM-12, the city's most common single-family districts, and is not allowed in RMF-22. The major catch is occupancy: the unit is only for family members or relatives and cannot be rented or leased. Ordinance read July 2026 | The same secondary living unit use covers attached units, with the same district split as detached; if attached it must have its own entrance not connected to the primary structure. Two narrower attached options exist: caretaker's quarters (inside or attached by a common wall, allowed in RE and VG among residential districts, with recorded use covenants required before a building permit) and garage apartments (a dwelling unit built as part of a private garage, allowed only in RM-12, RMF-22, DB, NMU, and RMU, where it counts toward density). Ordinance read July 2026 | No square-footage cap stated for a secondary living unit; the limits are one bedroom, one kitchen, and one bathroom maximum, plus the district's primary-structure envelope (setbacks, height, lot coverage). Expressly exempt from the district's minimum dwelling size. One secondary living unit per lot. | Not required | None for a secondary living unit: §3.3.6.L expressly exempts it from the off-street parking requirements and from the garage or carport requirement. A garage apartment (RM-12, RMF-22, DB, NMU, RMU only) requires 1 space per dwelling unit; the main house remains subject to 2 spaces per single-family detached dwelling. | In RE, RS-20, RS-15, and VG, a secondary living unit is a permitted accessory use built under a standard building permit subject to the §3.3.6.L standards. In RS-7.2 and RS-5, Arlington's workhorse single-family districts (7,200 and 5,000 sq ft minimum lots), and in RM-12, it requires a Specific Use Permit, adopted by ordinance after a Planning and Zoning Commission public hearing and City Council approval. It is not allowed at all in RMF-22. Ordinance read July 2026 |
| Austin | Allowed | Allowed | Within the Subchapter F (central-city 'McMansion') boundary: each new unit capped at the greater of 0.4 FAR or 2,300 sq ft; total site FAR capped at the greater of 0.55 or 3,200 sq ft for two-unit use (0.65 or 4,350 sq ft for three-unit). Outside that boundary, base zoning district limits control. Preserving a qualifying older dwelling excludes its preserved square footage from FAR. | Not required | None. Austin eliminated off-street parking minimums citywide (Ord. 20231102-028, Nov 2023): 'off-street motor vehicle parking is not required' except accessible spaces tied to what would formerly have been required. If parking is provided, placement rules in § 25-2-773(C)(2)-(3) apply (max four spaces in the front street yard; garage placement limits). | Permitted use |
| Brownsville | Allowed | Allowed | No more than 50 percent of the total floor area of the principal dwelling's living space; no fixed square-footage cap in the ordinance. | Not required | 1 off-street space per accessory dwelling unit, in addition to the principal dwelling's requirement (2 per single-family detached dwelling). TN districts need only 50 percent of the minimum, and downtown (DT) form districts have no parking minimums. | Permitted use |
| Corpus Christi | Allowed | Not allowed | Lesser of the principal dwelling's gross floor area or a district cap: 1,000 sq ft in FR, RE, and RS-22; 800 sq ft in RS-15 and RS-10; 500 sq ft in RS-6 and RS-4.5, rising to 800 sq ft on lots over 10,000 sq ft. No floor-area cap for conversion of a legally conforming pre-1980 garage. | Required | No ADU-specific standard; §5.3.2.A is silent on parking. The parking table's Household Living catch-all requires 2 spaces per unit for uses without their own line, with a 1-to-2-space caretakers-quarters row as the nearest analogy; the CBD downtown district has no parking minimums. | Permitted use |
| Dallas | No by-right ADUs citywide. A detached rentable ADU needs either a Board of Adjustment special exception (available in any district) or location inside an adopted Accessory Dwelling Unit Overlay, which a neighborhood must petition for (50%+ of property owners). Ordinance read July 2026 | Same two paths apply. The overlay expressly regulates attached ADUs (max floor area the greater of 700 sq ft or 25 percent of the main use); the base special exception covers a rentable accessory dwelling unit without distinguishing attachment. A separate non-rentable 'additional dwelling unit' special exception also exists (51A-4.209(b)(6)(E)(i)), which requires a deed restriction against rental. Dallas Development Code Secs. 51A-4.510(c)(2)(C)(ii) and 51A-4.209(b)(6)(E)(i)-(iii)Full rules for Dallas Ordinance read July 2026 | In an ADU overlay: detached ADU 200 sq ft minimum, maximum the greater of 700 sq ft or 25 percent of the main structure; attached ADU maximum the greater of 700 sq ft or 25 percent of the main use; one story maximum. Outside an overlay (special exception path), general accessory structure caps apply: an individual accessory structure may not exceed 25 percent of the main building's floor area (excluding parking), all accessory structures combined 50 percent, and height may not exceed the main building. | Required | Overlay: minimum one off-street space, waived within 1,200 feet of a DART bus or transit stop, and reducible via the overlay petition (75 percent of owners) or by council on steering committee recommendation. Special exception path: if one additional off-street space is not provided, the board determines whether a traffic hazard results and may require one space as a condition. | Not by right anywhere in most cases (the city's own ADU page says so). Either a Board of Adjustment special exception (discretionary, $600 fee per the city page) or a city-council-adopted neighborhood ADU overlay, after which ADUs are permitted within the overlay subject to its standards. Dallas Development Code Secs. 51A-4.209(b)(6)(E)(iii)(aa) and 51A-4.510; City of Dallas ADU pageFull rules for Dallas Ordinance read July 2026 |
| Denton | Allowed | Allowed | 800 sq ft or 75 percent of the principal dwelling's square footage, whichever is greater. | Not required | None for the ADU; parking removed from the principal dwelling must be replaced on site. | Permitted use |
| El Paso | Allowed | Allowed | 800 sq ft gross floor area, or 1,200 sq ft on lots of 8,000 sq ft or more; no more than one bedroom; height may not exceed the principal dwelling; minimum lot 5,500 sq ft | For a detached ADU the owner must occupy either the principal unit or the ADU as their permanent residence, and may rent out both units only during a temporary absence of one year or less. The attached-ADU subsection (§20.10.035.B) does not repeat this requirement, so as codified the owner-occupancy rule is stated only for detached units; confirm with Planning whether the city applies it to attached ADUs in practice. Ordinance read July 2026 | No ADU-specific minimum stated; on-site ADU parking is required only if the ADU takes vehicular access from an alley. The principal house itself requires 2 spaces per dwelling unit. | Permitted use |
| Fort Worth | Habitable accessory buildings are permitted by right as accessory uses in all one- and two-family districts, but in one-family districts they 'may be used only as an accessory dwelling unit and may not be used as a separate independent residence'. The ADU definition further limits occupancy to temporary guests or family members of the main dwelling and bars cooking equipment, so this is a guest house or family quarters, not a rentable independent unit. Ordinance read July 2026 | Not allowed | No ADU-specific square footage cap; habitable accessory buildings may not exceed the height of the primary dwelling and count toward district lot coverage (for example 50% maximum in A-5). The lot-size-based table in § 5.301(b) (120 to 400 sq ft, or 2% of lots of an acre or more) applies only to NON-habitable accessory buildings. | Not required | No ADU-specific parking requirement in § 5.301. District standards require 2 spaces per dwelling unit behind the front building wall plus 1 per bedroom over three (for example A-5, § 4.705(d)(2)); because an accessory dwelling unit is not a separate dwelling unit under the code, no additional spaces are triggered in the text read. | Permitted use |
| Frisco | Allowed | Allowed | No square-footage cap stated for a Garage Apartment or Guest House. Size is limited indirectly: maximum lot coverage for all buildings combined (20 percent in RE up to 55 percent in OTR), a district height cap of 40 ft and 2.5 stories, and accessory-structure setbacks per Figure 4.06.04.1. | Owner occupancy of the main house is mandatory whenever the Garage Apartment or Guest House is rented or offered for rent; that is the rental gate in §4.06.03(C)(2). The Garage Apartment definition additionally builds in an owner-occupied main structure regardless of rental. A Guest House used only to house the owner's guests carries no separate occupancy test beyond its definition tying it to the owner of the main residence. Ordinance read July 2026 | No separate parking ratio for the unit itself. The Use Chart assigns Garage Apartment and Guest House the single-family parking reference, which requires a minimum of 2 enclosed garage spaces plus 2 paved stacking spaces behind the front property line. | Permitted use |
| Garland | Garland defines an Accessory Dwelling as attached or detached, so detached ADUs exist in the code, but no zoning district allows one by right. A detached Guest House (not for rent) needs a Specific Use Provision (SUP) from City Council and is eligible only in the AG, SF-E, SF-10, and SF-7 districts; a rentable Accessory Dwelling Rental Unit is SUP-eligible only in AG and SF-E. Owners of typical SF-5 small-lot homes, townhouses, and duplexes have no ADU path at all, and an ordinary accessory building may never be lived in without that SUP. GDC §6.03 (Dwelling, Accessory); §2.51 Land Use Matrix (2 Attachment 1, p. 3); §2.58(C)Full rules for Garland Ordinance read July 2026 | The same three Accessory Dwelling use categories cover attached units; every definition says the unit may be either attached or detached, and the Land Use Matrix does not distinguish the two forms. An attached ADU therefore also requires an SUP in the same districts: Guest House in AG, SF-E, SF-10, SF-7; Rental Unit in AG and SF-E; Guard/Manager/Caretaker in AG, LC, HC, IN. No district grants attached ADUs by right. Ordinance read July 2026 | No fixed square-foot cap; an accessory dwelling's building area may not exceed 30 percent of the main structure's floor area, and all accessory buildings combined share that 30 percent budget, except a single accessory building is never limited below 600 sq ft. Height capped at 15 ft over 200 sq ft and 25 ft (or the main structure's height, whichever is less) over 500 sq ft. | Not required | Guest House: 1 space per dwelling unit. Rental Unit: 1 space for efficiency and 1-bedroom units, 2 spaces for 2 or more bedrooms. Guard/Manager/Caretaker unit: 2 spaces. All in addition to the main house's 2 enclosed spaces. | Every accessory dwelling type appears in the Land Use Matrix only with an 'S': allowed solely upon approval of a Specific Use Provision, Garland's conditional-use instrument granted by City Council. No district shows a 'P' (by right) for any ADU. Ordinary accessory buildings are by right in residential districts but may not be inhabited without that SUP, and any accessory building over 20 sq ft needs a building permit under GDC Chapter 4. GDC §2.51 Land Use Matrix (legend and Accessory Dwellings rows); §2.58(C), (F)Full rules for Garland Ordinance read July 2026 |
| Grand Prairie | Not allowed | An accessory apartment built in or added to the main house makes the lot a two-dwelling-unit property, and the definition expressly points to the 2-Family/Duplex row of the use charts. That use is permitted by right only in the SF-A (Single Family Attached) and 2F (Two Family) districts and is blank (not permitted) in every single-family detached district. Where allowed, the unit must meet all eight accessory-apartment criteria including minimum size, a two-bedroom cap, owner occupancy, and no street-facing evidence of the unit other than an entrance. UDC Art. 30, Accessory Apartment criteria A-H; UDC Art. 4, §22 Use Charts and §4.1.2 legendFull rules for Grand Prairie Ordinance read July 2026 | Minimum 400 sq ft; no more than 35 percent of the original dwelling's total floor area; maximum two bedrooms; occupancy capped at four people. | Required | One parking space for each adult resident of the accessory apartment, on top of the main dwelling's parking. | There is no Specific Use Permit category for accessory apartments: in the two base districts where a second unit can exist (SF-A and 2F, via the 2-Family/Duplex classification) it is a by-right use needing only standard building permits, and in all other base districts it is simply not permitted. A large share of the city sits in Planned Development districts whose case-by-case use lists override the base chart. Garage conversions into living space of the main home (not a separate unit) are permitted across all single-family districts. Ordinance read July 2026 |
| Grapevine | Grapevine allows a detached accessory dwelling unit, but only in the R-20 Single-Family District (20,000 sq ft minimum lots), where it is a listed permitted secondary use with standards in Section 42.C.6. The more common R-12.5, R-7.5, and R-5.0 districts do not list ADUs and each limits the lot to one single-family detached dwelling, so most Grapevine homeowners cannot build one. Where allowed, the ADU must be a site-built structure in the rear yard behind the primary home; modular and manufactured units are prohibited. App. D Sec. 13.B.2; Sec. 42.C.6; Sec. 12 (definition); contrast Secs. 14 to 16Full rules for Grapevine Ordinance read July 2026 | Not allowed | 750 sq ft maximum building area; one story and 16 ft maximum height; limited to one bedroom | Not required | 1 additional space for the ADU, located behind the front building line, on top of the base 2 spaces per dwelling for single-family homes; driveway and parking must be shared with the main house | Permitted use |
| Houston | Allowed | Allowed | 1,500 sq ft for a detached second dwelling unit (the threshold for the lot to remain classified single-family residential under Chapter 42); parking tiers change at 1,000 sq ft. No sq ft cap is written for an attached second unit within a single two-unit building. The current code contains no 900 sq ft threshold. | Not required | None for a second unit up to 1,000 gross sq ft; one additional space if 1,001 to 1,500 sq ft, provided the first unit meets its own requirement. Numeric minimums do not apply in the market-based parking area (greater Downtown, Midtown, EaDo) or along primary transit-oriented development streets. | Permitted use |
| Irving | Irving has no accessory dwelling unit ordinance; the closest uses are guest quarters and servants quarters, treated as accessory uses to a single-family home. The Residential Land Use Table leaves the guest and servant's quarters row blank (prohibited) in all fifteen base residential districts and marks it permitted only in the S-P site plan column: each single-family district allows the quarters only if the lot is approved as an S-P-1 site plan district, a case-by-case rezoning by city council. Without that approval, a detached accessory building may not contain dwelling accommodations at all, defined to include a kitchen, indoor bath, built-in HVAC, gas service, more than two rooms, or even a closet. UDC-2 §2.4.2 (Residential Land Use Table); §§2.4.4 to 2.4.9 (for example R-6 §2.4.8(b)); UDC-3 §3.1.7; UDC-9 §9.3 defs. 66, 87, 169Full rules for Irving Ordinance read July 2026 | The code draws no attached-versus-detached distinction for quarters: the district regulations address a private garage, guest quarters, or public utility use whether attached or detached, and the S-P-1 requirement applies either way. An accessory building physically attached to the house is treated as part of the primary structure, and no residential district lists a second dwelling unit on a single-family lot as a permitted use, so an attached in-law suite functioning as a separate dwelling also requires the S-P-1 rezoning. Ordinance read July 2026 | No quarters-specific cap; size is fixed by the approved S-P-1 site plan. Generally applicable limits: detached accessory buildings other than garages are capped at 10 percent of lot area up to 2,500 sq ft total on lots under half an acre (no cap on larger lots), max height 10 ft, extendable to 20 ft with added setbacks; a detached garage is capped at 800 sq ft or 10 percent of lot area, whichever is greater, up to 1,200 sq ft. | Not required | No separate quarters ratio; parking for S-P-1-approved quarters is fixed on the council-approved site plan. Base single-family standard: homes built on or after April 5, 2018 need a 2-car garage of at least 400 sq ft plus 2 additional off-street spaces. A short-term rental in a single-family property must show 4 on-site spaces or 1 per bedroom, whichever is greater. | There is no by-right or staff-level path: guest or servants quarters require rezoning the lot to an S-P-1 site plan district, granted only by city council ordinance on the owner's written request after Planning and Zoning Commission recommendation and public hearing. This is a discretionary legislative approval, heavier than a typical conditional use permit, and the land use table offers no CUP alternative for quarters. Building permits and a certificate of occupancy follow the rezoning. Ordinance read July 2026 |
| Killeen | Killeen has no accessory dwelling unit ordinance; the closest thing is a detached guest house, permitted in only two districts: A-R1 (agricultural single-family, 1-acre minimum lots) and SR-2 (suburban residential). One guest house per lot is allowed by right there, capped at 25 percent of the main home's floor area, and it can never be rented or leased. In the common R-1, SR-1, and SF-2 single-family districts, only ordinary accessory buildings and servants' quarters (living quarters for household staff, never a separate domicile) are allowed, so a detached independent second dwelling is not available on most lots. §31-172(b)(1) (A-R1); §31-185.2(b)(1) (SR-2); §31-186(13) (R-1); §31-2 (servants' quarters)Full rules for Killeen Ordinance read July 2026 | Not allowed | Guest house: max 25 percent of the principal residence's floor area, excluding garages (A-R1 and SR-2 only). Accessory buildings placed in a required rear yard are separately capped at 20 ft in height and, combined, at 25 percent of that rear yard area. | Not required | 2 off-street spaces per single-family lot (at least 180 sq ft each, open or enclosed), plus 1 additional off-street space if a guest house is built. | Permitted use |
| Laredo | Laredo has no ADU ordinance; the phrase accessory dwelling unit appears nowhere in either code. In the R-1 and R-1B single-family districts only one dwelling per lot is allowed, so a detached second unit with its own kitchen is prohibited there. A detached second dwelling on one lot is expressly allowed only in the R-3 Mixed Residential District, and only if it is occupied by a relative, produces no rental income, the lot provides 3,000 sq ft of area per dwelling unit, and 1.5 parking spaces per unit are on the lot. The RS district additionally permits guest quarters separated from the principal structure as an accessory use, but a guest quarters is not a dwelling unit. Ordinance read July 2026 | An attached second unit with its own kitchen makes the building a two-family dwelling (duplex), which the land use chart permits by right in AG, R-2, R-3, R-O, AE, B-1, B-1R, CBD, and B-3, but not in the R-1, R-1A, R-1B, R-1-MH, RS, or RSM districts. Separately, the chart lists Servants Quarters as a permitted use in R-1, R-2, R-3, RSM, RS, R-O, and most business districts; the code never defines that term, and the RS district text limits servants quarters to space for domestic employees within the main structure. An attached family or staff suite is broadly achievable, but a true second dwelling attached to a house in an R-1 district is not authorized. LDC §24-63.2 (Two Family (Duplex) and Servants Quarters rows); §24-65.2(3); Appendix A (Dwelling, Two-Family)Full rules for Laredo Ordinance read July 2026 | No ADU-specific floor-area cap in the code. The R-3 second dwelling requires at least 3,000 sq ft of lot area per dwelling unit; horizontal duplex lots require 6,000 sq ft minimum; vertical duplex and multifamily lots require 1,200 sq ft of lot area per unit plus 400 sq ft per additional bedroom. Residential height is capped at 2.5 stories and 35 ft in R-1 and RS (2 stories in R-1A and R-1B; 4 stories and 50 ft in R-2 and R-3). | No section requires the owner to live on the property, but the only path to a second unit on a single-family lot (R-3) requires the additional dwelling to be occupied by a relative and bars using it for rental income, which ties the unit to the resident household in practice. Duplexes in the districts that allow them carry no occupancy restriction at all. Read the R-3 relative condition as stricter than a typical owner-occupancy rule, since the unit cannot be rented to anyone. Ordinance read July 2026 | 2 off-street spaces per single-family dwelling unit; 4 spaces for each duplex; the R-3 second dwelling requires at least 1.5 spaces per dwelling unit on the lot; R-1B lots require at least 3 spaces. Single-family and duplex spaces are 8 by 16 ft, must be paved with concrete or brick, and stacked (tandem) spaces are permitted. | Permitted use |
| Lewisville | Allowed | Not allowed | Minimum 400 sq ft; maximum 800 sq ft or 50 percent of the principal building's floor area, whichever is greater. The cottage may not exceed the height of the principal building, and the house, cottage, and all other accessory buildings together may not exceed the district's maximum lot coverage. | Required | 1 space per backyard cottage, in addition to the single-family home's own requirement (1 garage space plus 2 driveway spaces). A cottage space on pavement outside a garage may not be a tandem space and must be contiguous with the driveway serving the main house. | In the residential use table, Backyard Cottage is marked A (allowed) in AO, R-18, R-12, R-9, and R-7.5 and S (Special Use Permit) in R-6, R-5, and ETH; in the mixed-use table it is A in OTMU-1 and OTMU-2 and not allowed in OTC, MU, and MU-90. On most standard single-family lots a cottage is by right with a building permit only, but the small-lot R-6 and R-5 districts and ETH require a discretionary Special Use Permit. Cottages are not allowed at all in duplex, townhouse, multifamily, manufactured-home, and nonresidential districts. Ordinance read July 2026 |
| Lubbock | Allowed | Allowed | No fixed square-footage cap; the ADU floor area may not exceed the primary dwelling's floor area. Minimum lot area 10,000 sq ft (6,000 sq ft in the Neighborhood Infill or Community Infill Overlay districts). On lots under half an acre, accessory buildings together are also capped at 10 percent of lot area. | Required | 1 off-street space for the ADU in addition to the spaces required for the primary dwelling (2 per dwelling unit for a single-family detached house). The off-street parking schedule does not apply in base Mixed-Use districts. | Permitted use |
| McAllen | Allowed | Allowed | On single-family lots: 650 sq ft maximum if the lot is smaller than 6,500 sq ft, no numeric maximum on larger lots, but never larger (or taller) than the primary dwelling; minimum ADU size 450 sq ft. On townhouse through multiplex lots the caps run 500 to 900 sq ft with 5,000 to 13,500 sq ft lot minimums. | Required | 1 space per dwelling unit for the ADU. No parking minimums apply in the Downtown (DT) subdistrict, and 25 to 50 percent reductions are available in M-1, M-2, UT, and for infill development. | Permitted use |
| McKinney | Allowed | Not allowed | Up to 50 percent of the primary dwelling's total square footage; if the primary dwelling is 1,200 sq ft or less, up to 75 percent. Same height limit and setbacks as the primary dwelling, set behind the front face of the house. | Not required | 1 space for the ADU, waived if the lot already has at least 4 parking spaces (at least 3 in the H Historic Overlay). The single-family home itself requires 4 spaces per dwelling, 2 enclosed. | Permitted use |
| Mesquite | A detached backyard ADU is possible only with a Conditional Use Permit approved by the City Council, and only in the AG agricultural and R single-family districts (R-1, R-1A, R-2, R-2A, R-3) on lots of at least 21,780 sq ft (half an acre). The use table leaves the D duplex, TNMR, and A multifamily columns blank, which §2-201.D defines as prohibited. The unit must sit in the rear yard behind the rear facade of the house, meet the primary structure's setbacks with at least a 10 ft rear setback, and one ADU per property is the limit. Zoning Ordinance (App. C) §2-203(C)(3); §2-603.N intro, N.1, N.9, N.10; §2-201.B, .DFull rules for Mesquite Ordinance read July 2026 | Mesquite's definition of an accessory dwelling covers attached space too: any area beyond the principal dwelling with living, sleeping, and bathroom facilities that either contains a kitchen or has its own entrance not from inside the main house. Such a suite is the same Accessory dwelling unit use, so it needs the same City Council CUP and half-acre lot. The §2-603.N standards are written for backyard structures (rear-yard placement, 15 ft height cap), so an attached unit would likely need the council to modify conditions, which the ordinance allows. A plain garage conversion into extra living space within the primary dwelling (no kitchen, interior access) is a separate, simpler path under §2-202.E with building permits. Zoning Ordinance §6-102 (Dwelling unit, Accessory); §2-203(C)(3); §2-603.N; §2-601.B; §2-202.EFull rules for Mesquite Ordinance read July 2026 | 500 sq ft maximum; up to 1,000 sq ft on Agriculture-zoned lots over 1 acre. Height capped at 15 ft or the primary structure's height, whichever is less. | Required | 4 off-street spaces total on the property, behind the front and exterior side building lines, each independently accessible (no stacked or tandem parking). The citywide single-family baseline is 2 spaces. | ADUs are marked 'C' in the residential use schedule: a Conditional Use Permit that only the City Council can grant after a Planning and Zoning Commission hearing and recommendation. Under §5-310 a CUP is processed as a zoning map amendment: public notice, two public hearings, and an adopted ordinance that stamps the property with a '-CUP' suffix on the zoning map. Approval is discretionary ('may be approved'), and the council can attach or modify conditions. Before October 2022 this was a Board of Adjustment special exception; Ord. No. 4990 switched it to the CUP process. Zoning Ordinance §2-201.B; §2-203(C)(3); §2-603.N; §5-310.A, .D; Ord. No. 4990 (10-3-2022)Full rules for Mesquite Ordinance read July 2026 |
| Midland | Midland defines an Accessory Dwelling Unit as living quarters attached to or detached from the principal residence, and the 4.03 Use Chart lists the use with an 'S' (Specific Use Designation required) in the AE, CE, SF-1, SF-2, and SF-3 districts only; the column is blank (prohibited) in MH, TH, 2F, MF-16, MF-22, and all nonresidential districts. A detached second unit is possible on a single-family lot, but only after a case-by-case Specific Use Designation approved by City Council, and the unit can never be rented. A mobile home, travel trailer, or RV cannot serve as the detached unit. Zoning Ordinance §2.01 def. 5; §4.03 Use Chart; §4.09.C.1.d (PDF pp. 9, 71, 109)Full rules for Midland Ordinance read July 2026 | The same Accessory Dwelling Unit use covers attached quarters: the definition says attached or detached, and §4.09.C applies its limits to ADUs including units attached to the principal residence. The same Specific Use Designation requirement and district list (AE, CE, SF-1, SF-2, SF-3) apply, and the attached unit must respect the district's setbacks and lot coverage and match the home's architecture. Zoning Ordinance §2.01 def. 5; §4.03 Use Chart; §4.09.C.1 (PDF pp. 9, 71, 109)Full rules for Midland Ordinance read July 2026 | Living area capped at 1,000 sq ft or 30 percent of the principal residence's area, whichever is less; one ADU per tract. Detached units also count against the accessory-building caps: all accessory buildings limited to 10 percent of the property (15 percent on 5+ acres), 15 ft height on lots under 22,000 sq ft, 5 ft side and rear setbacks, and 10 ft separation from the principal building. | Not required | Two off-street spaces per dwelling unit for single-family uses, in addition to any garage spaces; the Use Chart's parking reference for the ADU row points to this same single-family schedule (§6.02.C.1). All spaces must be at least 9 by 20 ft on curbed, paved surfaces. | An Accessory Dwelling Unit is never allowed by right anywhere in Midland. In the five districts where it is possible (AE, CE, SF-1, SF-2, SF-3) it requires a Specific Use Designation, which is processed as a Zoning Map Amendment (rezoning): application with site plan, Planning and Zoning Commission review, and City Council approval, with discretionary conditions and possible time limits. Zoning Ordinance §4.03 Use Chart legend; §9.07.A-C; §4.09.D.10 (PDF pp. 71, 110, 167-168)Full rules for Midland Ordinance read July 2026 |
| Pasadena | Pasadena has no zoning, so no ordinance authorizes or prohibits a detached second dwelling; the code never mentions accessory dwelling units and contains no citywide one-dwelling-per-lot rule. What actually decides the question on a given lot is the private deed restrictions recorded with the Harris County Clerk: most Pasadena subdivisions carry them, the city's law department is authorized to sue to enforce them, and the housing code defers to them for any multifamily conversion. On a lot whose restrictions allow it, a detached second dwelling proceeds as ordinary permitted construction under the 2024 IRC with 25 ft front and 5 ft side/rear setbacks, plus planning site plan review because a two-dwelling lot is no longer single-family residential as defined. Ordinance read July 2026 | An attached second unit makes the building what the code calls a duplex, a building type Pasadena's ordinances expressly recognize (the setback article defines duplex residential buildings, the adopted residential code covers one- and two-family dwellings, and the parking table has a two-family category). No use-district rule forbids it, but the housing chapter says nothing in the code permits establishing or converting a multifamily dwelling in a residential addition except where the deed restrictions permit, and 2021 replat rules lock in single-family plat restrictions. Pull the subdivision's recorded covenants from the Harris County Clerk before designing a conversion. Ordinance read July 2026 | No ADU-specific or citywide size cap (no zoning). Practical thresholds: residential garages, shops, barns, barn/residence and similar structures over 1,200 sq ft trigger planning site plan review; storage buildings under 100 sq ft are exempt from a building permit; new residential lots must be at least 6,000 sq ft; deed restrictions may impose their own size limits. | Not required | 2 off-street spaces per dwelling unit for single-family and two-family residential (garage spaces may count), so a house plus second unit needs 4 spaces total. Each residential lot must also have a driveway sized for 2 off-street spaces, and paved parking must sit at least 5 ft from property lines. | Permitted use |
| Plano | Allowed | Not allowed | 1,100 sq ft or 50 percent of the main home's gross habitable floor area, whichever is more restrictive; minimum 400 sq ft; height capped at the main dwelling's height; 6,000 sq ft minimum lot. ED-district accessory dwelling units: minimum 500 sq ft with 1 acre of lot per unit. | Not required | 1 off-street space for the backyard cottage, in addition to the 2 spaces required per single-family dwelling; tandem parking may not be used to satisfy it. | Permitted use |
| Port Aransas | Allowed | Allowed | At least 300 and less than 600 sq ft of air-conditioned living space (air-conditioned garages excluded). No ADU-specific height cap; district height and setback rules apply. | Not required | 1 additional off-street space per ADU bedroom, on top of the primary home's parking (2 spaces per single-family dwelling). The parking table's 2-space-per-unit minimum expressly excludes ADUs. | Permitted use |
| San Antonio | Allowed | Allowed | 800 sq ft, or 50 percent of the primary home's gross floor area if larger, capped at 1,600 sq ft (excluding covered porches) in single-family districts; 1,200 sq ft cap in the RE district; in FR, each ADDU must be 300 to 1,200 sq ft. Detached ADUs max 25 ft and 2 stories. | Required | None for an ADU of 800 sq ft or less; a detached ADU over 800 sq ft gross floor area must provide 1 off-street space. | Permitted use |
| Southlake | Southlake has no independent detached ADU. What it allows is one detached 'domestic employee or family quarters' (sleeping, cooking, and sanitation) built as part of a detached residential garage, and only in the large-lot districts AG, RE-5, RE-7, SF-1A, SF-1B, and SF-2. Occupancy is limited to on-premises domestic employees or family members of the owner, and the quarters may never be rented or used as a separate domicile. In SF-30, SF-20A, and SF-20B a detached quarters is not authorized; only attached or internal quarters are. Ordinance read July 2026 | One attached or internal domestic employee or family quarters is a by-right accessory use across essentially all single-family districts (AG, RE-5, RE-7, RCS, SF-1A, SF-1B, SF-2, SF-30, SF-20A, SF-20B, plus approved single-family uses in R-PUD, EC, and DT). The quarters must be attached to or internal within the principal dwelling, must remain accessory and subordinate to the single-family use, and cannot be rented or occupied as a separate domicile; only one quarters is allowed per residence. This is a restricted in-law or staff suite, not an independent second unit. Ordinance read July 2026 | Detached garage quarters: max 50 percent of the garage building area if attached to the garage, or 100 percent if above the garage's first floor, with the footprint capped at 1,000 sq ft (excluded from the district's cumulative accessory-building area). Attached or internal quarters: no separate numeric cap, limited by subordination to the main dwelling. | No clause expressly orders the owner to live in the main house, but quarters occupancy is defined entirely relative to the owner: occupants must be domestic employees working on the premises or family members of the owner of the premises, and the quarters can never be rented or used as a separate domicile. That occupant restriction effectively ties the quarters to the owner's household; it cannot function as a unit independent of it. Zoning Ord. 480 §4.2 (Domestic Employee and Family Quarters); §34.1(jj), (kk); §34.2(d)Full rules for Southlake Ordinance read July 2026 | 2 off-street spaces per dwelling unit, exclusive of in-garage parking, for single-family detached dwellings; no separate parking requirement is stated for domestic employee or family quarters. | Permitted use |
| Waco | Allowed | Allowed | Greater of 500 sq ft or 30 percent of the primary dwelling's floor area (garage excluded from the primary's calculation); one bedroom maximum; height may not exceed the primary dwelling. Existing structures adapted or renovated into ADUs are exempt from the size cap. | In single-family residence districts (R-E and R-1A/B/C), the property owner must sign a notarized affidavit, recorded with the McLennan County Clerk's Office, affirming the owner lives in either the main house or the ADU, and leasing both units at once is unlawful there. The code states no owner-occupancy requirement for ADUs in the R-2, R-3, O-1, or O-2 districts. Owner occupancy is defined by title records plus evidence like voter or vehicle registration. Ordinance read July 2026 | 1 off-street space for the ADU, in addition to the 2 spaces required for the primary dwelling. ADU parking access must be the same as the primary dwelling's, except alley access is allowed where the lot abuts a public alley. | Permitted use |
Summarized from each city's ordinance text, most recently read July 2026. Tap a value marked with an info icon to see exactly what it depends on, straight from the ordinance. Nearly every value has zone, lot-size, or process caveats beyond that; the per-city pages carry the full notes and code citations. Treat this as orientation, not a permit determination.
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Reading the table
- Detached ADU is the make-or-break column for backyard cottages: minimum lot sizes (often 8,000 to 14,500 sq ft) hide behind many of the "Allowed" values, so check your lot before celebrating.
- Attached / internal (basement apartments, additions) is legal almost everywhere and is usually the path of least resistance.
- Approval: "Permitted use" means staff-level sign-off; "Conditional use" means a public hearing, which adds time, cost, and uncertainty.
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