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

The big four families

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.