Which plat does Houston require?

There are two plat requirements in chapter 42, not one. Sec. 42-20 attaches to dividing property; Sec. 42-22 attaches to building or enlarging. They have different triggers and different exemption lists, and a project can need both, one, or neither.

Gather these details first

Use your current plat or survey and a sketch of the proposed changes. Answer both groups of questions, then save the result URL with your project notes. The tool does not look up your recorded plat or determine whether an exemption applies to your property.

Use the result as a list of questions for the city and your project team. It is not an approval or a buildable-home count.

Are you dividing property?

Are you dividing property into more than one lot or tract?

Does one of Sec. 42-21’s three exceptions apply?

Does it require or propose a new street?

Does it require or propose dedicating an easement for public water, wastewater collection or storm sewer lines?

Is it a vacating plat?

Is it a replat?

Is it an amending plat?

How many lots does it create?

Does every lot front on an existing street?

Are you building?

Are you building new, or enlarging any exterior dimension of a building, structure or improvement?

Does one of Sec. 42-22’s six exemptions apply?

Nothing here triggers either requirement

Subdivision plat

Not triggered

Sec. 42-20(a) attaches to the subdivision of property. If you are not dividing property, it is not engaged — though a development plat may still be, below.

Development plat

Not triggered

Sec. 42-22 attaches to new construction or the enlargement of any exterior dimension of a building, structure or improvement. Without that, it is not engaged.

What this rests on

    What it cannot tell you

    • Whether deed restrictions add requirements of their own. They are private agreements, the holder can sue on one, and city approval of a plat is no defence to that suit. Inside the city limits the city has its own powers as well: Sec. 10-552(a) makes failure to comply with a recorded restriction — after notice of Chapter 10 article XV — a civil violation of the Code carrying up to $1,000.00 per day, and Sec. 10-553 lets the city attorney sue and seek repair or demolition. Sec. 10-551 limits that regime to subdivisions within the city limits, so it does not reach the extraterritorial jurisdiction.
    • Whether the property sits in the extraterritorial jurisdiction rather than the city. Both Sec. 42-20 and Sec. 42-22 reach the ETJ, but other parts of chapter 42 treat it differently.

    The thing most summaries get wrong

    Class I, class II and class III are usually described as a hierarchy you are sorted into by the size of your subdivision. Sec. 42-23(a) says otherwise: class I and class II plats are optional and may be used in lieu of a class III plat. A class III plat stays available to anyone. What the criteria in Sec. 42-23(c) and (d) decide is which of the two lighter options you may choose — not which one you are assigned.

    What genuinely forces a class III plat is narrow and listed in Sec. 42-23(b): a new street, a dedicated easement for public water, wastewater collection or storm sewer lines, or a vacating plat.

    This is how the code reads; confirm with the city — or ask a builder who's actually pulled this permit in Houston. The authoritative text is the Houston Code of Ordinances; permitting questions go to Houston Permitting Center.