Los Angeles County Zoning Ordinances

As described on their web site (which also has applications for zoning and subdivision, as well as contacts for the offices).

Also, "How to Request a Subdivision"

ZONE R-1: Single Family Residence

Permitted Uses:
Single family residences (22.20.070 - 22.20.100)

Minimum Required Area:
Unless otherwise specified: 5,000 sq. ft./lot (22.52.100, 22.52.250)

Maximum Height Limit:
35 feet from existing or excavated grade (22.20.110) (unless modified by a special standards district such as a community standards district.)

Minimum Required Parking:
2 covered parking spaces per single family residence (22.52.1180)

Standard Yard Requirements:
Front Yard: 20 feet (22.20.120), except as provided in special Standards District

Rear Yard: 15 feet or 20% of average depth of shallow lot, but not less than 10 feet (22.20.120 and 22.48.110)

Side Yards: Interior Lot: 5 feet or 10% of average width of narrow lot, but not less than 3 feet (22.20.120 and 22.48.100)

Corner Lot: 5 feet except on reversed corner lot, which is 10 feet (22.20.120)

Development Standards:
(See 22.20.105 regarding development standards for single-family residences)

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ZONE R-2: Two Family Residence

Permitted Uses:
Two family residences (or duplex), single family residences (22.20.170 - 22.20.200)

Minimum Required Area:
Unless otherwise specified:
- 5,000 sq. ft./lot (22.52.100)
- 2,500 sq. ft./unit (22.52.270)

Maximum Height Limit:
35 feet from existing or excavated grade (22.20.210). See special standards district

Minimum Required Parking:
- 1 1/2 covered spaces + 1/2 uncovered space per unit for each 2- family residence (duplex)
- Single Family Residence, same as in R-1 zone (22.52.1180)

Standard Yard Requirements:
Front Yard: 20 feet (22.20.220)
Rear Yard: 15 feet or 20% of average depth of shallow lot, but not less than 10 feet (22.20.220 and 22.48.110)
Side Yards: Interior lot: 5 feet or 10% of average width of narrow lot, but not less than 3 feet (22.20.220 and 22.48.100)
Corner lot: 5 feet, except on reversed corner lot, which is 10 feet (22.20.220)

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ZONE R-3: Limited Multiple Residence

Permitted Uses:
Apartment houses, uses permitted in Zone R-1 and R-2 (22.20.260 - 22.20.290)

Minimum Required Area:
Unless otherwise specified:
- 5000 sq. ft./lot (22.52.100)
- 1452 sq. ft./unit or as otherwise limited by the General Plan (22.20.310 and 22.20.060)

Maximum Height Limit:
35 feet from existing or excavated grade (22.20.300)

Minimum Required Parking:
- Each bachelor apartment unit, 1 covered space
- Each efficiency or 1 bedroom apartment unit, 1 1/2 covered spaces
- Each 2 bedroom apartment unit, 1 1/2 covered + 1/2 uncovered spaces
- See R-1 and R-2 zones
- Guest parking required for apartments with a minimum of 10 units at a ratio of 1 space for each 4 units (22.52.1180 and 22.20.330)

Standard Yard Requirements:
Front Yard: 15 ft., except as provided (22.20.320)
Rear Yard: 15 ft. or 20% of average depth of lot, not less than 10 ft. (22.20.320 and 22.48.110)
Side Yards: Interior Lot: 5 feet or 10% of average width of narrow lot, but not less than 3 feet (22.20.320 and 22.48.100) Corner Lot: 5 ft., except on reversed corner lot, which is 7 1/2 feet (22.20.320)

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ZONE R-4: Unlimited Residence

Permitted Uses:
Apartments, rooming and boarding houses, uses permitted in zones R-1 and R-2 (22.20.340 - 22.20.370)

Minimum Required Area:
Unless otherwise specified:
- 5000 sq. ft./lot (22.52.100)
- 871 sq. ft./dwelling or as otherwise limited by the General Plan (22.20.390 and 22.20.060)

Maximum Height Limit:
Total floor area not to exceed 13 times the buildable area (22.52.050)

Minimum Required Parking:
Same as R-1, R-2, and R-3, based on the type of structure (22.52.1180 and 22.20.400)

Standard Yard Requirements:
Front Yard: 15 feet (22.20.380), except as provided in Special Standards District
Rear Yard: 15 feet or 20% of average depth of shallow lot, but not less than 10 feet (22.20.320 and 22.48.110)
Side Yards: Interior Lot: Same as in R-1, plus 1 foot for each story above 2 stories, maximum required 16 feet (22.20.380)
Corner Lot: 5 feet, except on reversed corner lot which is 7 1/2 feet (22.20.380)

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ZONE R-A: Residential Agriculture

Permitted Uses:
- Single family residences
- Crops (field, tree, bush, berry, row and nursery stock) (22.20.410 - 22.20.440)

Minimum Required Area:
Unless otherwise specified 5000 sq. ft./lot (22.52.100, 22.52.250)

Maximum Height Limit:
35 feet (22.20.450)

Minimum Required Parking:
2 covered parking spaces per single family residence (22.52.1180)

Standard Yard Requirements:
Front Yard: Same as R-1 (22.20.450)
Rear Yard: Same as R-1 (22.20.450)
Side Yards: Same as R-1 (22.20.450)
Corner Lot: See 22.20.105 regarding development standards for single family residences

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