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Zoning codes — what R-1, C-2, M-1, MU mean and why your house is one

Zoning codes look like license plates and are about as readable. Every US city (except Houston) divides its land into zones with letter+number codes that govern what can be built, how big, how dense, and what activities are allowed.

Published 2026-04-25 · Last reviewed 2026-09-24 · methodology

Common zoning codes and what one big city allows in each

Code	What it means	What Los Angeles allows there
A1	Agricultural	Farming, one-family homes, parks, golf courses. Minimum lot 5 acres.
R1	One-family residential	One house per lot (plus home occupations). Minimum lot 5,000 sq ft.
R2	Two-family residential	R1 uses plus two-family dwellings (duplexes). Minimum lot 5,000 sq ft.
R3	Multiple dwelling	R2 uses plus apartment buildings and small child care (up to 20).
R4	Multiple dwelling, denser	R3 uses plus churches, schools, child care, homeless shelters.
R5	Multiple dwelling, densest	R4 uses plus clubs, hospitals and hotels.
C1	Limited commercial	Local retail stores under 100,000 sq ft, offices, hotels, clinics; R3 housing also allowed.
C2	Commercial	C1 uses plus service stations, garages, auto sales and retail with limited manufacturing; R4 housing allowed.
C4	Commercial	C2 uses with some limits; R4 housing allowed.
CM	Commercial manufacturing	Wholesale, storage, clinics, limited manufacturing; R3 housing allowed.
M1	Limited industrial	Limited industrial and manufacturing uses. No homes, hospitals, schools or churches.
M2	Light industrial	M1 uses plus more industrial uses and storage yards. No homes.
M3	Heavy industrial	Any industrial use; nuisance-type uses must be 500 ft from any other zone. No homes.

Right-hand column: Los Angeles Department of City Planning, Generalized Summary of Zoning Regulations (updated January 2026). Most US cities use the same letters (R, C, M), but each sets its own rules, so your city's zoning ordinance is the binding text. Source

The big four families

Cities write zoning codes with or without hyphens. This guide uses R-1, C-2, and M-1 in prose; the Los Angeles table below keeps that city's official R1, C2, and M1 labels. They mean the same codes.

R = Residential. R-1 is single-family detached; R-2/R-3/R-4 escalate to duplex / townhouse / multi-family. R-5+ are typically high-rise apartments.

C = Commercial. C-1 is neighborhood retail; C-2 is general/strip-mall commercial; C-3/C-4 are downtown commercial / mixed-use commercial.

M (or I) = Manufacturing / Industrial. M-1 is light industrial (warehousing, light fabrication); M-2/M-3 escalate to heavy industry.

MU = Mixed Use. Rapidly growing category that blends residential + retail + office in one zoning district. Found in 'walkable urbanism' planning.

Why your zoning matters

Property value: R-1 single-family is typically the most expensive per-square-foot housing. Adjacent C-2 or M-1 can lower your value if you back up to it.

What you can build: R-1 typically prohibits ADUs (accessory dwelling units), short-term rentals (Airbnb), and home businesses with customer traffic. Some cities have relaxed these statewide (CA SB-9, OR HB-2001).

Setbacks: how far structures must be from property lines. R-1 typically 25ft front, 5ft side, 20ft rear. R-2/R-3 reduce these.

Lot coverage: max % of lot that buildings can cover. Often 40% in R-1.

Height: typically 35ft max in R-1, rising in higher zones.

Special districts

Overlay zones: layered on top of base zoning. Historic district overlays restrict facade changes. Coastal overlays restrict view-blocking. Floodplain overlays add construction requirements.

PUD (Planned Unit Development): site-specific zoning negotiated for a single project. Common for large-scale developments.

What zipradar shows

For top-25 US cities with structured zoning data, we pull the dominant base zoning code in your ZIP and translate it to plain English ('R-1 = single-family residential').

Houston has no zoning by city law — we say so. Elsewhere we link to the local planning department's zoning portal where coverage is unstructured.