Diamond Bar · Building on your lot

Building on your lot in Diamond Bar

Diamond Bar sets its own limits on accessory structures and on fences in hillside and slope areas. It also has its own chapter on home-based businesses.

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Key points

Accessory structures: Diamond Bar limits detached accessory structures in residential zones to 15 feet and one story, and no higher than the main home.
Hillside fences: In hillside and slope areas, Diamond Bar limits walls and fences to 6 feet; ones visible from roadways must be open.
Home businesses: Diamond Bar has its own chapter on home-based businesses.

Each rule below is marked Diamond Bar code or CA state law and links to the section it comes from (checked October 2026). General information, not legal advice.

Fences and walls

Diamond Bar code What Diamond Bar's code adds
Height anywhere on the lot	Walls and fences can be at most 6 feet tall and must be see-through. Applies: Hillside and slope areas: walls and fences visible from roads or public rights-of-way. § 22.22.130 · code text Walls and fencing, not exceeding six feet in height, visible from roadways or public rights-of-way shall be visually open and non-opaque. Privacy walls and fences can be at most 6 feet tall. Applies: Hillside and slope areas: next to buildings, to create private outdoor areas. § 22.22.130 · code text Privacy walls and fences, not exceeding six feet in height, are allowed adjacent to structures, in order to provide private outdoor areas.

Sheds, garages and other accessory structures

Diamond Bar code Diamond Bar limits detached accessory structures in residential zones to 15 feet and one story, and no higher than the main home.

All 14 Diamond Bar rules on sheds, garages and other accessory structures, with the code text →

Solar panels and EV chargers

Diamond Bar code The building official issues permits when the application meets the city checklist and laws; electronic applications and signatures accepted. Administrative, nondiscretionary review; a permit is issued when the application meets the checklist and standard plan; only one inspection.

All 6 Diamond Bar rules on solar panels and EV chargers, with the code text →

Tree removal

Diamond Bar code The director may waive a separate tree removal permit. Yes, a permit is required.

All 8 Diamond Bar rules on tree removal, with the code text →

Building in a flood zone

Diamond Bar code What Diamond Bar's code adds
Floodplain permit	A development permit is needed before building or developing in any special flood hazard, flood erosion or mudslide (mudflow) area. § 18.108.100 · code text A development permit shall be obtained before construction or development begins within any area of special flood hazards, areas of flood-related erosion hazards or areas of mudslide (i.e., mudflow) established in section 18.108.050.
Building in a floodway	No encroachments, including fill and new construction, unless a registered professional engineer certifies no flood level rise. Applies: Applies in designated floodways, for flood levels during the base flood discharge. § 18.108.170 · code text Prohibit encroachments, including fill, new construction, substantial improvements, and other development unless certification by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.
Height of the lowest floor	The lowest floor, including basement, must be at or above the base flood elevation. Applies: New or substantially improved homes and other structures in special flood hazard areas. § 18.108.130 · code text New construction and substantial improvement of any structure shall have the lowest floor, including the basement, elevated to or above the base flood elevation. Lowest floor at least the flood map's depth number, in feet, above highest adjacent grade; 2 feet if none. Applies: New or substantially improved homes and other structures in flood zone AO. § 18.108.130 · code text New construction and substantial improvement of any structure in zone AO shall have the lowest floor, including the basement, elevated above the highest adjacent grade at least as high as the depth number specified in feet on the FIRM, or at least two feet if no depth number is specified.

Building on a hillside

Diamond Bar code Finished slopes may be no steeper than 50% (2:1). Finished slopes may be no steeper than 67% (1.5:1).

All 5 Diamond Bar rules on building on a hillside, with the code text →

Noise and construction hours

Diamond Bar code 7:00 a.m. to 7:00 p.m. 6:30 a.m. to 8:00 p.m., never on Sundays.

All 13 Diamond Bar rules on noise and construction hours, with the code text →

Outdoor lighting

Diamond Bar code What Diamond Bar's code adds
Shielding	Shielding must hide the light source and its reflection from any point 5 feet or more beyond the property line. Applies: Applies where the light source is visible from outside the project boundary. Does not apply to single-family homes. § 22.16.050 · code text Where the light source is visible from outside the project boundary, shielding shall be required to reduce glare so that neither the light source nor its image from a reflective surface shall be directly visible from any point five feet or more beyond the property line.

Family child care homes

CA state law California law
Zoning	A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning Health & Safety Code § 1597.45(a)
Business license or fee	A city or county may not charge a business license, fee or tax to run a family child care home Health & Safety Code § 1597.45(b)
Local rules	Local limits on height, setbacks, lot size, health and safety must be the same as for every other home in the same zone Health & Safety Code § 1597.45(e)
Small home	Up to eight children, counting the provider's own children under 10 who live there Health & Safety Code § 1596.78(c)
Large home	7 to 14 children, counting the provider's own children under 10 who live there Health & Safety Code § 1596.78(b)

Group homes and residential care

Diamond Bar code What Diamond Bar's code adds
Distance between homes	Parolee-probationer homes must be at least 10,000 feet apart, measured from the nearest outside building walls. Applies: Applies to parolee-probationer homes. § 22.42.140 · code text To avoid over-concentration of parolee-probationer homes, there shall be a 10,000-foot separation requirement between parolee/probationer homes as measured from the nearest outside building walls between the subject use and any other parolee/probationer housing. Must be at least 1,320 feet from any other group home, school, college, day care, park, library, bar, tavern or off-sale alcohol business. Applies: Applies to parolee-probationer homes. § 22.42.140 · code text A parolee-probationer home shall not be located within 1,320 feet of any other group home, a public or private school (pre-school through twelfth grade), university, college, child day care center, family day care home, public park, library, bar, cocktail lounge, tavern or business licensed for off-site sales of alcoholic beverages as measured from any point on the outside walls of the parolee/probationer housing to the nearest property line of the noted use.

Parking spaces required for homes

Diamond Bar code What Diamond Bar's code adds
Spaces per apartment or condo	2 spaces for each unit, in a garage. Applies: Applies to duplex housing units. § 22.30.040 · code text Duplex housing units \| 2 spaces for each unit in a garage.

Signs on homes

Diamond Bar code Signs up to 2 square feet per unit. Street address numbers must be at least 4 inches high. 1 sign per street frontage, at most 4 square feet and 6 feet high.

All 7 Diamond Bar rules on signs on homes, with the code text →

Trash and recycling carts

Diamond Bar code All residential property owners and occupants shall utilize the services of a collector Before 10:00 p.m. on the day the containers have been emptied

All 3 Diamond Bar rules on trash and recycling carts, with the code text →

Other Diamond Bar rules on this

Diamond Bar's code also has these chapters. We have not summarized their values on this page yet; read them in the library.

Home-based businesses (Sec. 22.42.070)
Pets at home: how many dogs and cats (§ 22.42.030)
Parking trailers on streets (§ 10.16.190) — public streets only
Hillside grading standards (§ 22.22.080) — hillside development only

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

How tall can a fence be in Diamond Bar?

In hillside and slope areas, Diamond Bar limits walls and fences to 6 feet; ones visible from roadways must be open.

Can I run a business from my home in Diamond Bar?

Diamond Bar has its own chapter on home-based businesses. Diamond Bar also has a related rule: Home-based businesses (Sec. 22.42.070).

What are the rules for building in a Diamond Bar flood zone?

Diamond Bar's code: A development permit is needed before building or developing in any special flood hazard, flood erosion or mudslide (mudflow) area. (§ 18.108.100); The lowest floor, including basement, must be at or above the base flood elevation. (New or substantially improved homes and other structures in special flood hazard areas.) (§ 18.108.130).

What are the outdoor lighting rules for homes in Diamond Bar?

Diamond Bar's code: Shielding must hide the light source and its reflection from any point 5 feet or more beyond the property line. (Applies where the light source is visible from outside the project boundary. Does not apply to single-family homes.) (§ 22.16.050).

Can I run a family child care home in Diamond Bar?

California law sets this for every city, including Diamond Bar: Zoning: A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning (Health & Safety Code § 1597.45(a)); Business license or fee: A city or county may not charge a business license, fee or tax to run a family child care home (Health & Safety Code § 1597.45(b)); Local rules: Local limits on height, setbacks, lot size, health and safety must be the same as for every other home in the same zone (Health & Safety Code § 1597.45(e)); Small home: Up to eight children, counting the provider's own children under 10 who live there (Health & Safety Code § 1596.78(c)); Large home: 7 to 14 children, counting the provider's own children under 10 who live there (Health & Safety Code § 1596.78(b)).

Where are group homes and residential care homes allowed in Diamond Bar?

Diamond Bar's code: Parolee-probationer homes must be at least 10,000 feet apart, measured from the nearest outside building walls. (Applies to parolee-probationer homes.) (§ 22.42.140); Must be at least 1,320 feet from any other group home, school, college, day care, park, library, bar, tavern or off-sale alcohol business. (Applies to parolee-probationer homes.) (§ 22.42.140).

How many parking spaces does a home need in Diamond Bar?

Diamond Bar's code: 2 spaces for each unit, in a garage. (Applies to duplex housing units.) (§ 22.30.040).

General information, not legal advice.

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