State Law | Texas vs California

Texas vs California Multiplex Rules: Side by Side (2026)

California sets these rules for small multiplexes at the state level: SB 9 for two homes and a lot split, a state ADU law, a statewide rent cap. Texas leaves the number of homes on a lot to each city and uses state law for other things: lot sizes on large new tracts, housing on commercial land, zoning protests and tenant rules. This page puts the two states side by side, with a source for every cell, and links to the full pages in both guides.

The Comparison Table

Each cell links to the statute, agency file or page it comes from. Population uses the US Census Bureau's July 1, 2025 estimates for both states so the two columns are measured the same way.

Texas facts checked October 2026; California facts from the VanPlex California guide, checked October 2026. The Proposition 13 cell links to the California property tax page, which cites the constitutional text.

Row by Row

Population

The Census Bureau's Vintage 2025 estimates put California at 39,355,309 and Texas at 31,709,821 on July 1, 2025. Texas had 29,145,505 people in the 2020 Census. California's Department of Finance publishes its own figure for January 1, 2026, with a different date and method, so this page uses the Census numbers for both states.

Permits for two- to four-unit buildings

In the Census Bureau's 2025 state permit file, Texas issued permits for 3,178 two-unit buildings and 727 buildings of three or four units. California issued 1,748 and 330. Houston alone permitted 1,054 two-unit buildings. The Census counts each building by the homes it holds. ADU rules are compared in their own row below.

Two homes on a single-family lot

California's SB 9 (2021) requires ministerial approval, which is a staff check against fixed rules with no hearing, of up to two primary units in a single-family zone. The state housing agency's SB 9 fact sheet says it "facilitates the creation of up to four housing units in the lot area typically used for one single-family home." In Texas the city decides under Local Government Code 211.003. Austin allows up to three units on SF-1, SF-2 and SF-3 lots of 5,750 square feet; Dallas allows one home per single-family lot. See the California SB 9 page and the Austin page.

Splitting a lot

Under California Government Code 66411.7, an SB 9 lot split makes two parcels, neither smaller than 40 percent of the original lot, and each at least 1,200 square feet unless the city sets a smaller minimum. The applicant signs an affidavit of intent to live in one unit for three years. In Texas, dividing land into building lots needs a plat under city rules, and the city must approve, approve with conditions, or deny a plat within 30 days after filing, under Local Government Code 212.009. Lot size comes from the city's own code.

Small-lot subdivision laws

Texas SB 15 (2025) bars a city of more than 150,000 people in a county of more than 300,000 from requiring a lot larger than 3,000 square feet on a new single-family tract of five acres or more with no recorded plat. California's SB 684 (2023) and SB 1123 (2024), in Government Code 66499.41, require ministerial review of a map that creates 10 or fewer parcels with 10 or fewer homes on qualifying urban lots. See the California SB 684 page.

Accessory dwelling units

California Government Code 66323 requires staff approval, on a single-family lot, of one ADU and one junior ADU created inside the existing house or an accessory structure, plus one detached new ADU with 4-foot side and rear setbacks that the city may cap at 800 square feet. Under Section 66317, a complete application must be approved or denied within 60 days when a home already stands on the lot. Texas has no state ADU law: SB 673 (2025) stopped on the House calendar on May 26, 2025. Houston allows a detached second unit of up to 1,500 square feet, and Dallas needs an overlay or a special exception. See the Texas ADU page and the California ADU page.

Owner living on site

California Government Code 66315 bars cities from requiring an owner to live on a lot with an ADU. Texas has no state rule, so cities set their own: San Antonio's Unified Development Code (UDC), in Section 35-371, requires the owner to live in the main house or the ADU and to sign a notarized affidavit and a recorded covenant. An investor who will not live on the lot can add an ADU in California but not under San Antonio's ADU rule.

Neighbor protests and hearings

Texas HB 24 (2025) changed Local Government Code 211.0061: a protest against a rezoning that adds housing now needs owners of at least 60 percent of the land within 200 feet, and a majority of all council members can still approve it. California approves SB 9 and ADU projects ministerially, with no hearing, and Government Code 65905.5 limits a housing project that meets objective standards to five hearings after the application is complete.

Decision deadlines

Texas Local Government Code 214.904 gives a city 45 days to grant or deny a building permit application, give written reasons it cannot decide yet, or agree on a deadline; a city that misses it may not collect the permit fees and must refund them. California's SB 9 section, Government Code 65852.21, requires a decision on a complete application within 60 days, or it is "deemed approved." The California permit streamlining page covers more deadlines.

Rent limits

California's Civil Code 1947.12 limits rent increases over any 12 months to 5 percent plus the change in the cost of living, or 10 percent, whichever is lower, and the section ends January 1, 2030. Housing with a certificate of occupancy issued in the previous 15 years is exempt, so a new California fourplex sits outside the cap for its first 15 years. In Texas, Local Government Code 214.902 lets a city adopt rent control only after its council finds a housing emergency due to a disaster and the governor approves the ordinance.

Ending a month-to-month tenancy

Texas Property Code 91.001 ends a month-to-month tenancy on the later of the date in the notice or one month after notice is given, unless a signed agreement sets another period, and either side may give it. California's Civil Code 1946.2 requires just cause, stated in the notice, once a tenant has lawfully lived in a unit for 12 months, and a no-fault ending requires relocation help equal to one month's rent. See the Texas landlord page and the California tenant page.

Property tax limits

Texas limits value growth. Under Tax Code 23.23, a homestead's appraised value can rise by no more than 10 percent a year plus new improvements. Other real property valued at $5,320,000 or less in 2026 has a 20 percent yearly cap that expires December 31, 2026. Texas also exempts $140,000 of a homestead's value from school taxes under Tax Code 11.13. California's Proposition 13 (Article XIII A of the state constitution) caps the general property tax at 1 percent of full cash value, and that value can rise by no more than 2 percent a year from its base. New construction in California gets its own new base value. See the Texas property tax page and the California property tax page.

Energy codes

Texas sets a statewide minimum through its State Energy Conservation Office: Chapter 11 of the 2015 IRC since September 1, 2016 for one- and two-family homes of three stories or fewer, and the 2015 International Energy Conservation Code (IECC) for other buildings. Texas cities may adopt newer codes. In California, the 2025 Energy Code applies to buildings whose permit applications are submitted on or after January 1, 2026. See the Texas building codes page and the California energy code page.

Fire sprinklers

Since January 1, 2009, Texas Occupations Code 1301.551(i) has barred a city from requiring fire sprinklers in a new or existing one- or two-family dwelling. On the California side, this guide verified one sprinkler rule, in ADU law: under Government Code 66323, sprinklers are not required in an ADU or junior ADU if the main home does not need them.

Loan limits

The FHFA 2026 county file gives every Texas county the baseline four-unit conforming limit of $1,601,750. California counties range from that same baseline in Sacramento and Fresno counties to $2,402,625 in Los Angeles, Orange, Alameda, San Francisco and Santa Clara counties, with San Diego County at $2,123,100. See the Texas financing page and the California financing page.

Where to Go Next

Related on VanPlex: the California multiplex guide, the California SB 9 page in the global comparison and the Texas multiplex guide overview.

Frequently Asked Questions

Official sources (checked October 2026)