Lemon Grove | Legacy Homes

Maximum size 1,200 square feet

Side/rear setbacks 4 feet

Two story Yes

Building separation 10 feet

Soils Report No

Building Verification Survey No

Coastal permit (in some areas) No

Stormwater Mitigation No

San Marcos

On Lemon Grove single-family residential lots, you may build one ADU (either attached or detached) and one Junior ADU (JADUs have an owner occupancy requirement and must be converted from existing space within the primary residence).
Lemon Grove allows up to 2 detached ADUs for multifamily lots with an existing multi-family building. (Meaning: In order to build 2 ADUs, the property must already have at least a duplex on it, not just a single family dwelling)

Effective Jan 2025 (SB1211): Multifamily property owners are permitted to build as many ADUs as there are existing units, with a maximum of eight detached ADUs. This change is due to California state law and will pre-empt existing local laws that are not brought into conformance.

Non‐livable space within existing multi‐family structures may be converted into an ADU. Examples of areas that can be converted include storage rooms and garage spaces. The maximum number of ADU allowed in a multi‐family structure is equal to 25% of the number of existing multi‐family units in the structure. A minimum of one conversion ADU is allowed.

Lemon Grove allows for a detached or attached ADU up to 1,200 sqft. Note that the ADU of >1000 sqft may not be larger than the primary home.

ADUs up to 800 square feet are exempt from lot coverage requirements. (Meaning: You can build an ADU of this size even if you’re maxed out on lot coverages).
The maximum height for detached accessory dwelling units shall be sixteen feet. However, in some situations state law allows up to 20′, so a two story may be possible.

Due to recent state law change, detached ADUs within half a mile of major transit stops or high-quality transit corridors can use 4′ side & rear setbacks, up to 18 feet tall. An additional 2 feet can be added if the ADU’s roof pitch matches the primary dwelling. This 18’+2′ limit would allow for a two story unit.

The maximum height for internal and attached accessory dwelling units and junior accessory dwelling units shall be the same as the primary dwelling in the underlying zone.

Read more about two story ADUs and height limits.
An ADU shall utilize the same or complementary architectural style, exterior materials, and colors as the existing or proposed primary dwelling, and the quality of the materials shall be the same or exceed that of the primary dwelling.

ADUs must have 4′ minimum setbacks from rear and side-yard property lines, with front yard setback per zoning standards.
The minimum required distance between structures is 10′ from existing structures.

Yes, Lemon Grove requires in-person submission of applications for an ADU, which adds some time and expense.
No, Lemon Grove does not mandate soils reports for ADUs.
No areas are subject to Coastal requirements.

A parking space is not required for an ADU in any of the following instances:

Within a one-half mile walking distance from public transit, which includes bus stops.

Within an established historic district.

Converted from the existing space of a primary residence or accessory structure, or are attached to an existing or proposed primary residence.

Effective Jan 2025 (SB1211): When a garage, carport, covered parking structure, or uncovered parking space is demolished or converted for construction of an ADU, replacement parking will not be required.
If a parking space is required, it may be located within the setbacks and in an existing driveway as tandem parking. Parking spaces don’t need to be replaced when a garage, carport, or covered parking structure is demolished in conjunction with the construction of an ADU or converted to an ADU.

Lemon Grove ADU Regulations & Zoning