Journal ·
Glendale Hillside Building Rules: What the R1R Zone Allows
On a Glendale hillside lot the house size is capped by a floor area ratio that depends on which of three city districts the lot sits in, and the cap drops once the ground averages 40 percent slope. Height is two stories and 32 feet, with a third story allowed only on the steepest ground. A separate chapter bans building on mapped ridgelines and within 30 feet of a mapped stream. Los Angeles adds up slope bands; Glendale works by district, slope class and map, and the two do not convert into each other.
What does R1R zoning mean on a Glendale listing?
R1R is the Restricted Residential zone. Chapter 30.11 of the Glendale Municipal Code describes it as a zone that exists "to preserve and protect low density residential neighborhoods or approved overlay zone uses in hillside areas," while "permitting a substantial and reasonable beneficial use of such property." Its sibling, ROS, is Residential Open Space for undeveloped hillside land.
Both zones share one development table with the flatland R1 zone, but the hillside pair carries extra standards in section 30.11.040 that R1 does not, starting with a Hillside Development Review Policy that weighs every discretionary decision against the neighborhood "in terms of size, scale, bulk/mass, roofline orientation, setbacks, and site layout." The code text used here is current through Ordinance No. 6052, adopted May 19, 2026.
How much house can you build on a Glendale hillside lot?
Table 30.11-B sets the floor area ratio for ROS, R1R and R1 by district. District I allows 0.30 of the first 10,000 square feet of lot area, District II allows 0.40, District III allows 0.45, and in every district the lot area beyond 10,000 square feet counts at only 0.10. Which district a street falls in is a map question for the Planning Division, not a label on the zoning map.
Then the slope override applies. For lots "with an average current slope of 40% or greater," the ratio is 0.30 for the first 10,000 square feet and 0.10 after that, whatever the district. The table marks this rule N/A for R1, so it bites only in the hillside zones.
Worked example, District III, 15,000 square foot lot: 10,000 at 0.45 gives 4,500, plus 5,000 at 0.10 gives 500, for 5,000 square feet. The same lot at 40 percent slope: 3,000 plus 500, for 3,500 square feet. The slope survey took 1,500 square feet off the house before anyone drew a plan.
Garage area gets a partial exclusion in these three zones only: up to 500 square feet for dwellings under 3,500 square feet, up to 700 for larger ones. Lot coverage is capped at 40 percent including accessory buildings, and 40 percent of the lot must be permanently landscaped open space.
How tall can a house be in the R1R zone?
Section 30.11.040E limits a primary building in R1R and ROS to two stories and 32 feet, with an extra three feet for any roofed area pitched at least three in twelve. R1, by comparison, stops at 25 feet.
The unusual part is the third story. The same subsection permits "an additional story" where the primary building sits on a portion of the lot "having an average current slope of 40 percent (21.8 degrees) or steeper," measured on "the smallest possible polygon, in terms of area, necessary to enclose the primary building and having a maximum of four sides." This time the measurement runs around the footprint, not across the parcel.
Accessory buildings top out at 12 feet, or 15 with a pitched roof, and on ground falling away at five to one or steeper their downslope wall may not exceed 10 feet.
Who calculates the average current slope?
A registered civil engineer or licensed land surveyor, and the code fixes the method. The definition in Chapter 30.70 reads "S = 0.00229 IL/A," where I is the contour interval in feet, L is the total length of contour lines inside the project boundary in feet, and A is the gross area in acres. The survey must use a contour interval no greater than two feet at a scale of one inch to 100 feet or larger.
Slope is measured on the land "before any current grading or other terrain modification is commenced," meaning the ground as it stands when the new project starts.
Can you build on a ridgeline or near a stream in Glendale?
Not on a mapped ridgeline, and not within 30 feet of a mapped stream. Chapter 16.08 is written for subdivisions, but section 30.11.040B applies its ridgeline and stream sections to "all subdivisions, development, building, construction, and grading in the ROS and R1R zones."
Within a mapped primary ridgeline area, section 16.08.010 says "no grading, engineered slopes, housing construction, streets, utilities or other manmade features shall be permitted." Secondary ridgelines under 16.08.020 carry the same prohibition, with a hearing-only exception that limits structures to 15 feet or one story and retaining walls to five feet, no more than two in succession.
Blue-line streams under 16.08.030 are channels drawn in blue on the USGS 7.5 minute quadrangles. Nothing may be built within 30 feet of the centerline, and grading between 30 and 100 feet is allowed only if riparian habitat is fully preserved. The lines sit on the city's 200-scale topographic sheets, so a parcel can look like ordinary R1R on the zoning map and still carry a ridge or stream line.
How much grading does Glendale allow on a hillside lot?
Glendale does not set a cubic-yard cap the way Los Angeles does. It regulates the shape of the cut. Chapter 15.12 limits cut slopes to 50 feet of vertical height, rising to 100 feet only where the toe of the cut is at least 40 horizontal feet from the nearest downslope street. Fill slopes may not exceed 60 feet, or 120 with the same separation. Slopes are rounded into the natural terrain where conditions permit and planted on automatic irrigation as soon as rough grading is done.
Section 15.12.067 is the gate. The city engineer or building official "shall not issue a grading permit for a grading plan which is inconsistent with the intent and purpose of the hillside design guidelines," a document adopted by council resolution rather than codified.
One definition catches flatland buyers off guard: for this chapter, "hillside area" includes "any land located in the R1 or SR zones." An R1 lot on a gentle street is a hillside area for grading purposes.
Glendale R1R vs the Los Angeles Baseline Hillside Ordinance
| Rule | Glendale ROS / R1R | Los Angeles R1 hillside |
|---|---|---|
| Floor area method | FAR by district, 0.30 to 0.45 of first 10,000 sq ft | Sum of slope bands, 0.45 down to 0.30 |
| Steep ground | Whole lot drops to 0.30 at 40% average slope | Land over 100% slope counts at 0.00 |
| Floor area floor | None stated | 25% of lot or 800 sq ft, whichever is greater |
| Height | 2 stories, 32 ft, third story on 40% ground | Envelope height rules in LAMC 12.21 C.10(d) |
| Grading quantity | No cubic-yard cap; slope height limits of 50 and 60 ft | 1,000 cu yd by right in R1 |
| Ridgelines | Mapped primary and secondary ridgelines, no building | Only inside specific plans such as Mulholland |
| Slope survey | 2 ft contours, engineer or surveyor certified | 10 ft contours with 2 ft intermediates, same signers |
The Los Angeles figures come from Ordinance No. 184,802, Tables 12.21 C.10-2a and C.10-6, and are worked through in the Encino hillside rules explainer. An LA buyer can estimate floor area from a slope band map before offering. A Glendale buyer needs the FAR district and a certified slope figure.
What to check before writing an offer on a Glendale hillside home
- Zone and FAR district. Confirm ROS, R1R or R1, then ask the Planning Division which floor area district the street sits in.
- Average current slope. Get any certified slope map, or budget for one before removing contingencies on a project that adds square footage.
- The 40 percent line. A lot near it can lose a third of its floor area ratio or gain a story, depending on where the survey lands.
- Ridgeline and stream sheets. Ask the city to check the 200-scale topographic sheets for primary ridges, secondary ridges and blue lines.
- Retaining walls. In ROS and R1R, walls under three feet may sit anywhere in an interior setback; walls of three to five feet stay five feet off the line, per section 30.11.070.
- Lot history. R1R lots created before June 26, 1986 can take a new house at 7,500 square feet; the subdivision minimum today is 12,000.
- Overlays and utility. Part of the foothills sits inside a historic district, covered in the Glendale historic district guide, and service comes from the city's own utility, covered in the Glendale Water and Power note.
Q: Is the 40 percent slope measured on the whole lot?
For the floor area ratio, yes: Table 30.11-B refers to lots with an average current slope of 40 percent or greater. For the third story, no: section 30.11.040E measures the smallest four-sided polygon enclosing the primary building.
This article is general information drawn from the Glendale Municipal Code, not legal, engineering or land use advice. Code sections, maps and guidelines change, and a parcel can be affected by overlays not discussed here. Confirm your lot with the City of Glendale Planning Division before relying on any figure. Call Alla at (818) 699-5367 or use the enquiry form.
Looking at homes in the Glendale foothills? Start with the Glendale area guide.