Millbrae R-1LL zoning: height, setbacks and lot size

R-1LL (Single-family Residential Large Lot) is a zoning district in Millbrae. Every value below was read from the Millbrae Municipal Code and links to its section (read October 2026). State laws such as the ADU and SB 9 rules can allow more on a residential lot. General information, not legal advice — read the code text and check with the city before you build.

Development standards in R-1LL

The general rule for a typical lot in this zone. Zoning tables often attach notes, such as rules for corner lots, lots next to a residential zone, or new subdivisions only. Open “code text” under a value to see the table cell or sentence it was read from.

Maximum building height	30 ft § 10.05.0520 · code text Maximum height of structures shall be thirty feet, provided the uppermost five feet shall consist of a roof which slopes toward any adjacent street at a minimum slope of three inches per foot.
Minimum side setback	5 ft Applies: Interior side yard; may be reduced to 10% of lot width, but not below 3 ft. Exterior side: 10 ft. § 10.05.0520 · code text Five feet interior; however, the width of interior side yards may be reduced to ten percent of the lot width, but in no case to less than three feet.
Minimum lot size	10,000 sq ft § 10.05.0520 · code text Area: ten thousand square feet.
Maximum lot coverage	40% § 10.05.0520 · code text Lot coverage: forty percent.
Maximum floor area ratio (FAR)	55% § 10.05.0520 · code text Floor area ratio (FAR): fifty-five percent.
Maximum density	1 unit per 10,000 sq ft § 10.05.0520 · code text The minimum lot area per unit shall be ten thousand square feet.

When a different number applies

The code sets other values for particular lots, buildings or locations in R-1LL:

Maximum building height: 25 ft — If the roof slope toward an adjacent street is less than three inches per foot § 10.05.0520
Minimum front setback: 10 ft more than the walls below — Upper floor on any lot width: the second floor must parallel the ground floor along the front facade. § 10.05.0520
Minimum side setback: 10 ft more than the distance of the exterior building walls below — Upper floor on lots at least 55 feet wide; may be reduced by two feet for each one foot that the ground floor setback exceeds five feet, up to six feet § 10.05.0520
Minimum side setback: 7 ft more than the distance of the exterior building walls below — Upper floor on lots at least 45 feet but less than 55 feet wide; may be reduced by one foot for each one foot that the ground floor setback exceeds five feet, up to three feet § 10.05.0520
Minimum side setback: 5 ft more than the distance of the exterior building walls below — Upper floor on lots less than 45 feet wide; may be reduced by one foot for each one foot that the ground floor setback exceeds five feet, up to two feet § 10.05.0520

Not on this page

We did not find a general stories, front setback, rear setback limit for R-1LL in the zoning tables we read. The code may still set one elsewhere — check the Millbrae Municipal Code.

Other Millbrae zoning districts

Who this affects

HomeownersArchitects and designersDevelopersReal estate agents

Frequently asked questions

What is the maximum building height in Millbrae's R-1LL zone?

30 ft — Millbrae Municipal Code § 10.05.0520.

What is the minimum side setback in Millbrae's R-1LL zone?

5 ft (interior side yard; may be reduced to 10% of lot width, but not below 3 ft. Exterior side: 10 ft) — Millbrae Municipal Code § 10.05.0520.

What is the minimum lot size in Millbrae's R-1LL zone?

10,000 sq ft — Millbrae Municipal Code § 10.05.0520.

What is the maximum lot coverage in Millbrae's R-1LL zone?

40% — Millbrae Municipal Code § 10.05.0520.

What is the maximum floor area ratio (far) in Millbrae's R-1LL zone?

55% — Millbrae Municipal Code § 10.05.0520.

General information, not legal advice.