Learn the rules

In almost all cases, yes!

• ADUs and JADUs are allowed in all single-family (RS) and multifamily residential (RM) zones, except Single-Family Mobile Home (RS-MH).

• ADUs and JADUs that do not require an ADU permit (see details below) are also allowed in the Business/Residential Mixed-Use Zone (B/R-MU).

• There is no minimum lot size.

• Homeowners can build both an ADU and a JADU on their property, and multifamily building owners can build one or two ADUs, depending on the type of project (but no JADUs).

Homeowners can convert legally built structures (garage, barn, art studio, etc.) into an ADU. JADUs can be converted from an attached garage (but not detached). If you demolish your garage or other enclosed structure and build an ADU in its place, the ADU can take up the same footprint if it’s the same size and height of the structure it’s replacing. You may need to provide replacement parking; check with City staff and see our Guidebook for more details.

Demolition permits for an existing detached garage can be processed at the same time as the ADU permits. Note that garage conversion ADUs may require significant moisture barriers and other design elements in order to meet building codes.

ADUs and JADUs are allowed in all single-family (RS) and multifamily residential (RM) zones, except Single-Family Mobile Home (RS-MH). ADUs and JADUs that do not require an ADU permit (see details below) are also allowed in the Business/Residential Mixed-Use Zone (B/R-MU).

Homeowners can build both an ADU and JADU on their property. Multi-unit properties can have multiple ADUs, depending on the type and other details of the project.

The answer depends on the type of ADU and on your property. See ADU Rules and our Guidebook for more details on height, setbacks, and other rules.

In most cases, ADUs are limited to these sizes:

• Junior ADUs (JADUs) can be up to 500 square feet.

• Conversion ADUs have no limit on square footage (but are generally limited to the existing building’s envelope – see the Guidebook for more details).

• Attached and Detached ADUs can be up to 850 square feet for studio/ one-bedroom units and 1,000 square feet for two-bedroom units. Attached ADUs also cannot exceed 50% of the size of the primary house.

According to state law, you can build up to an 800 square foot ADU, as long as rear and side setbacks are at least 4 feet and it is not above 16 feet tall. No room behind or next to your main home? Talk to Planning Division staff to find out more about your options.

Until at least 2025, the City of Upland does not require homeowners to live on their property if it includes an ADU. However, JADU owners need to live in the primary unit or the JADU – and this will need to be recorded in a deed restriction for the property.

ADUs and JADUs in the City of Upland must be rented for at least 31 days at a time; short-term rentals are not permitted.

JADUs don’t require a new parking space. When a project is exempt from ADU Permits, there are no specific requirements about parking spaces. Confirm details with Planning staff.

When an ADU Permit is required, each ADU must have one off-street parking space, unless:

• The ADU is within 1/2-mile walking distance to transit;

• The ADU is within an Historic District or on a Historic Property;

• On-street parking permits are required and not provided to the ADU occupant;

• The ADU is located within one block of car-share access;

• The ADU is constructed along with a new house or multifamily building.

The off-street space can be tandem (directly behind another spot in the driveway) or located in setback areas (ask Planning Division staff for advice). Parking spaces must be at least 9’ wide by 19’ deep if unenclosed and at least 10’ wide by 20’ deep if enclosed.

If a garage, carport, or other covered parking structure is demolished or converted as part of an J/ADU project, those parking spaces do not need to be replaced.

You can convert your garage or other legally built structure (like a barn or art studio) into an ADU. Attached garages (but not detached) can also be converted into a JADU. If you demolish your garage or other detached structure and build an ADU in its place, the ADU must be the same footprint, size, and height of what it’s replacing.

Utilities:

• J/ADUs constructed along with a new single-family home must have separate utility connections and incur the normal connection fee and capacity charge.

• Conversion J/ADUs on a single-family lot are not required to have separate connections and connection fees/capacity charges are not required.

• All other J/ADUs require new, separate utility connections, subject to a connection fee or capacity charge that is proportionate to floor area or number of units.

Sewer lines Detached ADUs require a sewer line that connects laterally between the primary home and the public sewer line; not a connection directly to the primary home’s sewer line. Consider this requirement early on because it can require significant work and cost.

Septic Systems If the J/ADU connects to an onsite water-treatment system, the owner must include with the application a percolation test completed within the last five years or, if the percolation test has been recertified, within the last 10 years.

If your property is designated as a Historic Property or is located in a Historic District, you will need to apply for a Certificate of Appropriateness, which assesses whether your plans are compatible with your existing structure and/or the historic district. See the Permitting page for more details.