Last verified August 13, 2026
against Houston Code of Ordinances §42-190, 42-191
· LotCodex
A reserve is a parcel within a Houston subdivision plat that isn't a lot. Chapter 42 requires any tract not restricted to single-family residential use — detention, open space, a lift station — to be designated a reserve instead. Reserves are identified by letter rather than lot number, and each type has its own minimum size; an unrestricted reserve, for example, needs at least 5,000 square feet. Many plats also carry a mandatory one-foot reserve blocking street access until adjacent land is later platted.
Applies to: Any tract within a Houston subdivision plat that isn't restricted to single-family residential use, under Chapter 42, Article III, Division 4, Subdivision A. This page covers the general reserve designation, letter identification, minimum-size figures for unrestricted and compensating-open-space reserves, and the mandatory one-foot reserve at certain street stubs. It does NOT cover the detailed design standards for a specific reserve type beyond the minimum-size figures cited (e.g., the full design rules for compensating open space in Sec. 42-183, or the point-based standards of an open space amenities plan in Sec. 42-192), nor multi-unit residential (MUR) reserves under Sec. 42-237, which is not part of this archive.
Reserve type
Minimum size
Minimum street/driveway width
Minimum frontage
Unrestricted reserve
5,000 sq. ft.
60 feet (50 feet in a street width exception area)
60 feet
Restricted reserve — compensating open space
240 sq. ft.
50 feet (public street or Type 1 PAE)
12 feet
Restricted reserve — landscape or open space
None required
None required
None required
Selected reserve types from the Sec. 42-190(c) table — not exhaustive; see the full ordinance for restricted reserves (lift station, recreation, wastewater treatment, and others) not shown here.
Common questions
Why is my plat's detention pond labeled with a letter instead of a lot number?
Because Sec. 42-190(a) requires any tract not restricted to single-family residential use — a detention pond among them — to be designated a reserve, not a lot, and Sec. 42-190(b) requires every reserve on a subdivision plat to be identified by alphabetical letter rather than a lot number.
What happens if I don't know what a reserve will be used for yet?
Sec. 42-190(b) lets you plat it as an "unrestricted reserve" without committing to a use. An unrestricted reserve still has to meet its own minimum standards under Sec. 42-190(c) — at least 5,000 square feet, fronting a public street at least 60 feet wide (50 feet in a street width exception area), with 60 feet of frontage.
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.