How a Subdivision Gets Platted in Houston and Harris County

Every lot sold in a Houston-area subdivision traces back to one recorded document: the plat. It is where a tract of land becomes Lot 14, Block 2, and where streets, easements and reserves are dedicated for good.

What surprises people from other markets is how many hands touch it. Houston has no zoning, but it has detailed subdivision rules, and much of the region's new land sits where the city's rules and Harris County's both apply. Here is who approves what, in what order, and what has changed since Harvey.

Two governments, one plat

Every subdivision inside the City of Houston or its extraterritorial jurisdiction needs a plat under Chapter 42 of the City Code (§42-20). The Planning Director approves Class I plats and development plats; the Planning Commission approves the rest (§42-70).

Planning review covers the layout. Water, sewer and drainage are reviewed separately, outside the Planning Department.

Where the land sits in the Harris County part of the ETJ, state law requires county approval as well, and where the two sets of rules differ, the stricter one governs (Local Government Code §242.001). In practice the sequence runs: the city, then Harris County's Office of the County Engineer, then Commissioners Court, then recording in the County Clerk's map records.

Outside any city's ETJ, the county acts alone (§232.002).

Where the ETJ is, and why it moved

Houston's extraterritorial jurisdiction reaches about five miles beyond the city limits (§42.021), into Harris, Fort Bend, Liberty, Montgomery and Waller counties. Inside it, Chapter 42 applies even though the city does not otherwise govern the land.

Since SB 2038 (2023), landowners can petition to be released from an ETJ: the owners of a majority of the land by value, or more than half the registered voters. If the city does not act within the statutory window, the release happens automatically, and the land cannot be put back without the owner's request (§§42.104–.105). Land under a strategic partnership agreement, industrial districts and land near certain military bases are excluded.

The effect on a tract can be large. Released land is platted by the county alone, and a new utility district there needs no city consent. The cities' constitutional challenge to SB 2038 was still on appeal at last check, so confirm the current position with counsel before relying on a release.

The plat types Houston uses

Chapter 42 sorts plats by what they create (§§42-22 to 42-24).

Approvals last 12 months and can be extended once (§42-80). A master-planned community moves through this table many times: one general plan, then a preliminary and final plat for each section as it comes to market.

The sequence, step by step

For a new residential section with streets, the path generally looks like this:

1. General plan, if the tract will be platted in sections. It fixes the street pattern everything else must follow.
2. Preliminary plat for the section. This is where lot layout, reserves, building lines and street dedications are settled.
3. Engineering review of water, sewer and drainage, on its own track.
4. Final plat. Inside a city floodplain, it cannot be approved until the City Engineer approves the drainage plan (§19-13).
5. County approval in the Harris County part of the ETJ: the Office of the County Engineer, then Commissioners Court.
6. Recording with the Harris County Clerk. From that moment the lots legally exist.

The order of construction-drawing approval relative to the final plat varies by project and jurisdiction; ask the reviewing engineer rather than assuming it.

The 30-day shot clock

Texas put a clock on plat review in 2019 with HB 3167. A city must approve, conditionally approve or deny a plat within 30 days, or it is approved (§212.009). A denial or conditional approval must give written reasons citing the law relied on (§212.0091). The applicant can respond at any time, and the city then has 15 days to decide (§212.0095). A city cannot require an applicant to waive these deadlines (§212.0097).

HB 3699 (2023) narrowed what counts as a "plat" for the clock to preliminary plats, final plats and replats, which took general plans out of it, and required cities to publish their list of required documents.

Counties have their own version (§232.0025): 30 days from a complete application, and if the county does not act, the plat is approved and the fee refunded. The practical lesson for both is the same. The clock starts at a complete application, so completeness is where schedules are won.

Lot size and width rules

Houston dropped its old "suburban" category in 2013. Under Chapter 42 today:

• Minimum lot size is 3,500 square feet inside the city and 5,000 square feet in the ETJ (§42-181).
• Smaller lots are allowed where the plat provides compensating open space, on a sliding scale: the smaller the average lot, the more shared open space each lot must contribute (§42-182).
• Minimum width is 20 feet, or 15 feet inside the city under conditions (§42-185).

Deed restrictions and the product itself often push lots well above these floors. They are minimums, not a design.

Drainage after Atlas 14

The single biggest change to Houston-area platting in a decade came from rainfall data. NOAA Atlas 14 (2018) raised Harris County's 100-year rainfall by roughly 30 percent, so the new 100-year storm is about the old 500-year storm.

Harris County rewrote its regulations on that basis, effective January 1, 2019, and the City of Houston adopted Atlas 14 rainfall later that year. The Harris County Flood Control District publishes the design criteria manual, but it is the county and the city that regulate.

For a developer the consequences are concrete:

• More detention. Bigger storms mean bigger ponds, and the pond comes out of the land that would otherwise be lots. The lot yield guide covers how that deduction works.
• Fill must be offset. Under Harris County's rules, floodplain storage lost to fill in the 500-year floodplain must be replaced one-for-one, and the city's Chapter 19 requires lost storage to be made up as well.
• Higher floors. New building floors in the floodplain must sit at least 24 inches above the 500-year flood level under the county's rules, and 2 feet above it under the city's.

FEMA's draft MAAPnext flood maps were released in early 2026 and are not yet regulatory, but they are worth checking on any tract under contract.

What a recorded plat shows

A Houston-area plat records the things everyone downstream relies on (§§42-41, 42-190):

• Lots and blocks, numbered, with dimensions and areas
• Reserves, lettered, for tracts not used for single-family homes: detention, open space, landscape, amenity, commercial
• Streets and rights-of-way, dedicated to the public
• Easements for utilities and drainage
• Building lines setting how close a structure can be to a street

The distinction between a lot and a reserve matters more than it looks. A reserve generally cannot become a homesite without a replat, which is why a marketing map that blurs the two causes problems at closing. For how a plat differs from a site plan and a marketing map, see plat map vs. site plan vs. site map.

How long it takes

The Planning Commission works on a 14-day cycle, and the statutory clocks bound each review. No reliable source publishes a typical end-to-end time from general plan to recording, because the variables are the project's own: how complete each submittal is, how much drainage and utility engineering the section needs, whether it sits in a floodplain, and whether the county's review runs in parallel or after the city's.

What reliably adds time is predictable: an incomplete application, a drainage plan that has to be redesigned for Atlas 14, and a replat because the marketing plan changed after the preliminary plat. The finished-lot guide covers what happens after recording, when paper lots become finished ones.

What to check before you plat a tract

Most platting delays are knowable before the land is under contract. Six questions settle most of them:

• Which jurisdiction? City, ETJ or unincorporated county, and which county. In the Harris County part of the ETJ, plan for both reviews.
• Has anyone petitioned for ETJ release? A released tract plays by county rules alone, and the legal challenge to SB 2038 is a risk to price in.
• What already exists? A general plan, earlier plats or replats over the same ground, and their expiry dates.
• Where is the floodplain? Both on today's effective maps and on the draft MAAPnext maps, because fill mitigation and floor elevations follow from it.
• Who provides water and sewer? A city, an existing district or a new one, and whether creating one needs city consent.
• What does the title commitment show? Pipeline and utility easements cross a great deal of land in this region, and every one of them comes out of the lot layout.

Where a map fits

The recorded plat is the legal source for every lot, but it is drawn for a clerk, not a buyer. Between the general plan and the last recorded section, a community's lots exist in three states at once: recorded, approved but unrecorded, and planned.

An interactive plat map is built from the recorded plat itself, so lot and block numbers match the county's, and future sections are shaded as future rather than as available. When a replat changes lot lines, the new filing is what the map is updated from. The land developer view puts every section's status on one page.

The Bottom Line

In the Houston ETJ, a plat answers to two governments and one clerk. Chapter 42 sets the layout rules, Harris County applies its own, and the stricter one wins. The state's 30-day clocks keep each review moving, but only once the application is complete.

The rule that changed most is drainage. Since Atlas 14, detention, fill mitigation and floor elevations shape the plat as much as lot sizes do, and they are now the first thing to model on any tract. For the district that usually pays for those ponds and pipes, see Texas MUDs, explained.