Most single-family properties can accommodate additions. The development criteria are based upon the zoning designation of your property. You can obtain or verify your property's zoning information online by visiting the City's interactive GIS map and searching by street address or by Assessor’s Parcel Number (APN). When these development standards are applied to your property, they will determine the maximum size and configuration of the home on your property. Refer to Development Code Section 22.08.040 for development standards.
Some second-story additions, and all additions that increase the size of the house by more than 50% require Planning Commission approval. Contact the Planning Division for initial inquiries and more information by submitting online through the Planning inquiry form or by making an appointment with the Planning Division.
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You may find approximate locations of your property lines on Diamond Bar’s GIS Parcel Data Map or you may obtain a copy of the parcel map from the L.A. County Assessor’s Office website. However, the exact location of your property lines can only be verified by a licensed surveyor. The City cannot recommend any specific surveyor or survey company. You can search for California-licensed professional engineers and land surveyors by visiting the California Department of Consumer Affairs website.
Freestanding walls and fences do not require a building permit, but still require Planning Division approval through an over-the-counter application called a Zoning Clearance.
Please submit a Uniform Application, a site plan (example) showing property line dimensions, location and details of the wall/fence such as material, height, and color of the proposed wall/fence.
If the wall/fence is on a shared property line, please obtain authorization from the neighbor on the “Fence, Wall & Hedges Signature form.”
The purpose of a retaining wall is to hold back soil, typically at the base of a slope. Approvals or permits from the Building and Safety Division and the Public Works/Engineering Department may also be required depending on wall height and site conditions. In most cases, retaining walls that are not over three feet in height measured from the bottom of the footing to the top of the wall do not require a building permit. Refer to Development Code Chapter 22.20 and Section 22.22.080 (b)(7) for general height requirements for retaining walls.
Contact the Planning Division for initial inquiries and more information by submitting online through the Planning inquiry form.
If the storage shed is less than 220 square feet, it may be placed five feet from the property line or buildable pad/edge of descending slope. If 220 square feet or larger, setbacks shall be the same as required for the main structure. Refer to Development Code Section 22.08.040 for setback requirements for the main structure, or contact the Planning Division. The design of the storage shed shall be compatible with the main structure. Storage sheds that are less than 120 square feet and eight feet in height do not require a building permit, but still require Planning Division approval through an over-the-counter application called a Zoning Clearance. Please submit a Uniform Application, a site plan (example) showing property line dimensions, location and details such as building material, height, and color of the storage shed.
A setback is the distance by which a structure, parking area or other development feature must be separated from a lot line, other structure or development feature, or street centerline. Refer to Development Code Section 22.16.090 (2) for more details on how to measure setbacks.
All patio covers require Planning Division approval through an over-the-counter application called a Zoning Clearance. Please submit a Uniform Application, a site plan (example) showing property line dimensions, location, and details such as building material, height, and color(s) of the proposed patio cover. Refer to Development Code Section 22.42.110 for setback, height, design, and lot coverage requirements.
Freestanding patio covers and gazebos not exceeding 120 square feet (roof area) are exempt from building permits, but still must obtain Planning Division approval and comply with Development Code Section 22.42.110 for setback, height, design, and lot coverage requirements. Any patio cover exceeding 120 square feet and any patio cover attached to the house requires a building permit.
You may contact the Planning Division with initial inquiries and more information by submitting online through the Planning inquiry form.
All residential properties are allowed one ADU of at least 800 square feet. Depending on lot size and capacity, an ADU may be as large as 1,000 square feet. In addition to an ADU, single-family residences may also have a Junior Accessory Dwelling Unit (JADU). A JADU is created within the walls of a single-family residence and may share restrooms with the primary residence, and must contain a basic kitchen. JADUs are allowed up to 500 square feet. Please visit Development Code Section 22.42.120 for additional ADU requirements.
Once you have plans ready, you may submit through the Planning inquiry form. No additional forms are required at this stage. Please allow a few days for the Planning and Building and Safety Divisions to review for completeness. Once authorization is received, a planner will assist you on the next steps for formal building plan check submittal to the Building and Safety Division. There is a 15-working day turnaround once accepted by the Building and Safety Division. Every subsequent submittal is 10 working days. When all comments/corrections have been addressed, your permit will be issued for the ADU.
Yards and setback areas shall be landscaped with lawn, trees, shrubs, or other plant material, and shall be permanently maintained in a neat and orderly manner and substantially free of weeds, debris and dead, diseased or dying vegetation and broken or defective decorative elements of the landscaped area. Foliage in landscaped areas shall be mowed, groomed, trimmed, pruned and adequately watered so as to maintain healthy growing conditions and not detract from the appearance of the immediate neighborhood. Irrigation systems shall be maintained to prevent public health or safety hazards.
If you are proposing to modify your front yard with drought-tolerant landscaping, Planning Division approval through an over-the-counter application called a Zoning Clearance is required. Please submit a Uniform Application, a site plan (example) showing property line dimensions, details and location of the proposed landscape/decorative hardscape improvements (e.g., quantity and species of all drought tolerant plants, shrubs, trees, and decorative hardscape areas).
For a list of drought tolerant landscaping, refer to the CAL-IPC website and the L.A. County Drought Tolerant Handbook for some ideas. https://www.cal-ipc.org/
Store your bins out of public view (or screened) at any time with the exception of your designated trash day. All bins shall be relocated from the place of collection before 10 p.m. on your trash day.