Everything You Need to Know about La Mesa ADU Regulations

In La Mesa, the number of ADUs permitted depends on the property type. For single-family properties, current regulations allow one ADU, either attached or detached, plus one Junior ADU (JADU), which must be converted from existing space within the primary residence. Starting in 2025, however, updated state regulations clarify that single-family properties may have a total of three units: one detached ADU, one converted ADU within existing interior space, and one JADU within the primary residence. For multifamily properties, La Mesa currently permits up to two detached ADUs, plus additional conversions of existing non-livable spaces (such as garages or storage areas) into ADUs—up to 25% of the existing unit count, with a minimum of one allowed. Beginning January 1, 2025, under California’s SB 1211, multifamily properties may construct up to eight detached ADUs, or a number equal to the existing units, whichever is fewer, alongside the internal conversions already permitted.

Yes. Under current regulations, multifamily properties in La Mesa can have up to two detached ADUs per property, in addition to converting existing non-livable spaces such as garages, storage rooms, or basements into ADUs, up to 25% of the existing unit count, with at least one conversion allowed. Starting in 2025, California Senate Bill 1211 increases this allowance, permitting multifamily properties to build up to eight detached ADUs, or a number equal to the existing primary units, whichever is fewer, alongside these internal conversions.

In La Mesa, accessory dwelling units (ADUs), whether attached or detached, may be constructed up to a maximum size of 1,200 square feet. Junior ADUs (JADUs), however, are limited to 500 square feet and must be created from existing interior space within the primary residence. The city does not set a specific local minimum size, but state building codes require habitable spaces to be at least 150 square feet.

A detached ADU in La Mesa can be up to 1,200 square feet in size, regardless of the primary home’s size.

An attached accessory dwelling unit (ADU) in La Mesa may be constructed up to a maximum size of 1,200 square feet.

In La Mesa, height restrictions for accessory dwelling units (ADUs) depend on the zoning of the property. For single-family residential lots, ADUs must comply with the height limit of the underlying zoning district, which is typically 20 feet in lower-density residential zones (such as R1) and up to 30 feet in higher-density residential areas. Two-story ADUs are permitted if they meet these zoning height standards. However, for detached ADUs on multifamily lots, there is a specific height limit of 16 feet. Attached ADUs must comply with the same height limitations as the primary residence.

Yes, La Mesa allows two-story ADUs, provided they comply with height restrictions, which are generally 20 feet in lower-density zones and up to 30 feet in higher-density residential areas. Although two-story units are permitted, the city typically favors single-story designs, so approval depends on adherence to local height limits and design guidelines.

La Mesa’s ADU regulations do not explicitly address roof decks. Generally, roof decks are permitted if the ADU complies with height limits (typically 20 feet in lower-density zones, 30 feet in higher-density zones) and meets setback and privacy guidelines. However, due to privacy concerns, roof decks may be subject to additional review or restrictions by the planning department, especially if overlooking neighboring properties. It’s recommended to verify specific plans with the city, as roof decks are handled on a case-by-case basis.

In La Mesa, ADUs must be visually compatible with the primary home’s design, though the city does not mandate strict architectural conformity. Typically, ADUs should incorporate exterior materials, colors, and finishes that complement or match the main residence, and roof forms should align or harmonize with the primary dwelling. Within historic districts, ADUs must specifically match the style and character of the main home without impacting significant historic features. Design review is ministerial, meaning approval occurs without discretionary review, provided these basic compatibility standards are satisfied.

La Mesa does not have a specific limit on the number of bedrooms allowed in an ADU. However, the practical limit on bedrooms is governed by the overall size constraints—typically a maximum of 1,200 square feet for detached ADUs, or up to 50% of the primary home’s size for attached units—and California Residential Code requirements, including minimum bedroom sizes and egress standards. Homeowners may include multiple bedrooms within these guidelines, provided each bedroom meets applicable size and safety regulations.

Yes, in La Mesa, an Accessory Dwelling Unit (ADU) must include a kitchen. The La Mesa Municipal Code defines an ADU as an independent unit that provides its own kitchen, bathroom, living area, sleeping area, and entrance. For Junior Accessory Dwelling Units (JADUs), an efficiency kitchen is required, which includes a cooking facility with appliances, a food preparation counter, and storage cabinets appropriate to the unit’s size.

No, you cannot build an ADU without a kitchen in La Mesa. By definition, an ADU must include a kitchen to qualify as a fully independent living unit under La Mesa’s regulations.

In La Mesa, an ADU must include a full bathroom with toilet, sink, and bathing facilities (either a shower or bathtub) to comply with building code standards and qualify as an independent living unit.

An Accessory Dwelling Unit (ADU) can be detached, attached, or converted from existing space, with a maximum size of up to 1,200 square feet. It must include a full bathroom and kitchen, does not require owner occupancy, and may have separate utilities. In contrast, a Junior Accessory Dwelling Unit (JADU) must be built within the existing primary single-family home and is limited to 500 square feet. It requires at least an efficiency kitchen and may share bathroom facilities with the main residence. Additionally, JADUs mandate owner occupancy—meaning the owner must reside in either the primary home or the JADU—and they share utilities with the main dwelling.

In La Mesa, Accessory Dwelling Units (ADUs) are required to maintain a minimum side and rear setback of 4 feet, while front setbacks must match those required for the primary residence. However, when converting existing structures such as garages or accessory buildings into ADUs, these standard setbacks may not apply, provided the Fire Marshal or Building Official confirms that the existing setbacks are adequate for fire safety. These setback rules aim to ensure ADUs integrate safely and compatibly within residential neighborhoods.

In La Mesa, the setback requirements for construction depend on the type and location of the structure. For Accessory Dwelling Units (ADUs), a minimum setback of 4 feet from side and rear property lines is required, while the front setback must match the primary dwelling’s requirements. For primary dwellings and other structures, setbacks vary based on the specific zoning district. To confirm exact setback regulations applicable to your property, particularly for non-ADU structures, consulting the La Mesa Zoning Ordinance or contacting the city’s Planning Department is recommended.

In La Mesa, an Accessory Dwelling Unit (ADU) must maintain a minimum distance of 6 feet from existing structures on the property.

In La Mesa, an Accessory Dwelling Unit (ADU) must maintain a minimum distance of 6 feet from existing structures on the property, including the main house.

In La Mesa, building an Accessory Dwelling Unit (ADU) in the front yard is generally prohibited, as ADUs must conform to the front setback requirements applicable to the primary dwelling. However, California state law allows potential exceptions if the front yard represents the only feasible location due to unique property constraints, provided the ADU still complies with established front yard setbacks. To determine if your property qualifies for such an exception, it’s recommended to consult directly with the City of La Mesa’s Planning Division.

Yes, a building permit is required for all ADUs constructed in La Mesa, including new detached or attached units, conversions of existing structures, and Junior ADUs (JADUs). Permit approval ensures compliance with zoning laws, safety codes, and city standards.

Yes, La Mesa accepts digital submissions for Accessory Dwelling Unit (ADU) plans. Applications for ADUs and Junior ADUs (JADUs) can be submitted online through the Maintstar Portal.

Yes, in La Mesa, a soils report is required for constructing an Accessory Dwelling Unit (ADU). This report must be submitted at the time of application.

No, coastal development permits are not required for ADUs in La Mesa, as the city is not located within California’s coastal zone.

In La Mesa, a Building Location Verification Survey is required for new buildings and additions located within three feet or less of a property line. Since Accessory Dwelling Units (ADUs) must maintain a minimum four-foot setback from side and rear property lines, a Building Location Verification Survey is typically not required for ADU construction.

In La Mesa, accessory dwelling units (ADUs) do not require specific stormwater mitigation measures beyond standard building requirements. The city does not impose additional stormwater permits or special mitigation conditions exclusively for ADU projects.

In La Mesa, the plan review process for an Accessory Dwelling Unit (ADU) begins with submitting a complete set of plans and supporting documents through the city’s online portal. State law requires that La Mesa either approve or deny a fully completed ADU application within 60 calendar days, though the actual timeframe can extend if plan corrections or additional documentation are needed. During review, the city verifies compliance with zoning, building, and applicable local or state standards. Although some projects may finalize permits within a few months, it is advisable to anticipate additional time for any revisions or clarifications. For a more precise estimate and to ensure that all requirements are addressed, it is best to consult La Mesa’s Planning Division directly.

In La Mesa, utility meter requirements for Accessory Dwelling Units (ADUs) depend on the unit type and configuration. Interior or attached ADUs that are built entirely within an existing single-family home or accessory structure, with independent exterior access and adequate fire safety setbacks, typically do not require separate utility connections. However, detached ADUs often necessitate new or separate utility connections, including dedicated electrical meters, particularly when connection to existing utilities isn’t feasible due to site conditions. San Diego Gas & Electric (SDG&E) specifically mandates separate electric meters for all newly constructed ADUs to ensure accurate billing and proper service management.

In La Mesa, utility connection requirements for Accessory Dwelling Units (ADUs) depend on the unit’s type and layout. Interior or attached ADUs within existing single-family homes or accessory structures, having independent exterior access and adequate fire safety setbacks, typically do not require new or separate utility connections such as water and sewer. In contrast, detached ADUs often require separate utility connections, including dedicated electrical meters, especially when connecting to existing utilities isn’t feasible due to property conditions. Additionally, San Diego Gas & Electric (SDG&E) mandates separate electric meters for all newly constructed ADUs to ensure proper billing and service management.

In California, including La Mesa, homeowners associations (HOAs) cannot prohibit the construction of Accessory Dwelling Units (ADUs). Assembly Bill 670, enacted in 2019, renders any HOA rules that effectively prohibit or unreasonably restrict the construction or use of ADUs on single-family residential lots as invalid. However, HOAs may impose reasonable restrictions, such as ensuring the ADU’s exterior matches the main residence, provided these do not unreasonably increase the cost or effectively prohibit the construction of the ADU.

In La Mesa, assigning a separate address to an Accessory Dwelling Unit (ADU) is typically managed through the city’s Planning or Engineering departments. Although the city commonly grants separate addresses for ADUs to facilitate clear identification, emergency response, mail delivery, and utility services, the specific procedure can vary. For precise guidance on obtaining a separate ADU address, it’s best to consult directly with the City of La Mesa’s Planning Division.

In La Mesa, constructing an Accessory Dwelling Unit (ADU) on an empty lot is not permitted. ADUs are defined as residential units located on the same lot as an existing or proposed primary dwelling. Therefore, to build an ADU, there must be an existing or concurrently constructed primary residence on the property.

Yes, in La Mesa, existing non-livable spaces within multifamily properties, such as storage rooms, boiler rooms, passageways, attics, basements, or garages, can be converted into Accessory Dwelling Units (ADUs). The city allows for the conversion of these spaces into ADUs, with the number of conversion ADUs permitted being up to 25% of the existing multifamily units, with a minimum of one conversion allowed.

In La Mesa, the municipal code does not explicitly address the stacking or stacking of detached Accessory Dwelling Units (ADUs). Although two-story ADUs are permitted, they must comply with general height restrictions, typically limited to 16 feet unless the unit meets setback requirements, in which case greater heights may be allowed according to the underlying zoning district. Given this ambiguity, it’s recommended to consult directly with the City of La Mesa’s Planning Division to confirm feasibility and compliance for stacking or multi-level ADUs.

In La Mesa, current guidelines do not explicitly address the configuration of attaching two ADUs together. While the city allows multiple ADUs on a single property, especially for multifamily lots, the specific arrangement of connected or attached ADUs remains undefined. To clarify the feasibility and compliance of constructing attached or connected ADUs, it’s recommended to consult directly with La Mesa’s Planning Division.

In La Mesa, the regulations do not explicitly address the attachment of two Accessory Dwelling Units (ADUs) to each other. While the city permits multiple ADUs on certain properties, such as allowing up to two detached ADUs on multifamily lots with existing multifamily dwellings, the specific configuration of attaching two ADUs together is not clearly defined in the current guidelines. Given this ambiguity, it’s advisable to consult directly with the City of La Mesa’s Planning Division to determine the feasibility and compliance of such a project with local regulations.

Yes, in La Mesa, it is permissible to have both an Accessory Dwelling Unit (ADU) and a Junior Accessory Dwelling Unit (JADU) on the same property. The JADU must be contained entirely within the existing or proposed single-family residence and cannot exceed 500 square feet. The ADU can be either attached to or detached from the primary residence, with a maximum size of 1,200 square feet.

In La Mesa, parking for an Accessory Dwelling Unit (ADU) is generally not required if the ADU is within a half-mile walking distance of public transit, located in a historic district, or created by converting existing spaces such as garages or carports. Additionally, as of January 2025, replacement parking is not mandated when existing parking spaces are demolished or converted to build an ADU. However, if these conditions do not apply, providing parking may still be required, and any voluntary parking additions must comply with the city’s design standards outlined in the municipal code.

In La Mesa, while additional parking for an Accessory Dwelling Unit (ADU) is not required, any voluntarily provided parking must comply with design standards outlined in the city’s Municipal Code. These spaces can be situated within setback areas or configured as tandem parking within an existing driveway. To ensure compliance with all applicable design regulations, consulting directly with the City of La Mesa’s Planning Division is recommended.

In La Mesa, permit fees for Accessory Dwelling Units (ADUs) vary depending on the size and complexity of the project. To promote ADU development, the city waives the first $2,000 of applicable city fees for both ADU and Junior ADU (JADU) building permit applications. Additionally, exact costs are influenced by factors such as the scope and scale of the ADU. For an accurate fee estimate specific to your project, consulting the City of La Mesa’s Planning Division is advisable.

In La Mesa, the cost to build an Accessory Dwelling Unit (ADU) typically ranges from $220 to $600 per square foot, depending on factors like size, design complexity, materials selected, and site conditions. Smaller units, such as a 500-square-foot, one-bedroom ADU, generally cost around $300,000, while larger ADUs, like a 1,200-square-foot, three-bedroom unit, average approximately $450,000. Additional costs can arise from challenging site conditions, custom designs, premium materials, and permitting fees—although La Mesa waives the initial $2,000 in city permit fees. For an accurate estimate tailored specifically to your project, consulting local contractors or the La Mesa Planning Division is recommended.

Yes, in La Mesa, you are permitted to rent out your Accessory Dwelling Unit (ADU). However, rentals must be for terms longer than 30 days, as short-term rentals (less than 30 days) are not allowed.

In La Mesa, California, the municipal code does not explicitly outline regulations on short-term rentals for Accessory Dwelling Units (ADUs). However, under California state law, ADUs generally must be rented for periods exceeding 30 days, effectively restricting short-term rental uses such as Airbnb. Due to this regulatory nuance, property owners considering short-term rentals should verify specific local requirements by consulting directly with the City of La Mesa’s Planning Division.

In La Mesa, California, Accessory Dwelling Units (ADUs) cannot be sold independently from the primary residence; they must remain under the same ownership. Although Assembly Bill 1033 (AB 1033), enacted in 2023, grants local jurisdictions the option to permit separate condominium sales of ADUs, La Mesa has not adopted an ordinance allowing such sales. For the most current information or updates regarding this policy, consulting directly with the City of La Mesa’s Planning Division is recommended.

In La Mesa, homeowners interested in building an Accessory Dwelling Unit (ADU) have access to several financial incentives. The California Housing Finance Agency (CalHFA) has provided grants up to $40,000 to cover pre-development and non-recurring closing costs, although as of December 2023, the latest funding round has been fully allocated. Locally, the City of La Mesa encourages ADU construction by waiving the first $2,000 in city fees for ADU and Junior ADU permit applications, and ADUs under 750 square feet are exempt from impact fees. Homeowners seeking additional financing options may consider home equity loans or lines of credit. For the most current incentives and available financing methods, consulting local financial institutions or the City of La Mesa’s Planning Division is recommended.

In La Mesa, sustainability requirements for Accessory Dwelling Units (ADUs) primarily follow California’s Title 24 Building Energy Efficiency Standards, which mandate energy-efficient construction practices including insulation, window specifications, efficient heating and cooling systems, and lighting. Additionally, homeowners are encouraged to incorporate water conservation strategies, such as low-flow fixtures and drought-tolerant landscaping, and to select sustainable, eco-friendly materials for construction. Although La Mesa does not specify additional local sustainability mandates, compliance with state regulations and adopting environmentally responsible practices is recommended. For detailed guidance or information about potential local incentives, consulting the City of La Mesa’s Planning Division is advisable.

In La Mesa, Accessory Dwelling Units (ADUs) must adhere to California’s Title 24 Building Energy Efficiency Standards, which require energy-efficient design elements such as insulation, window efficiency, optimized heating and cooling systems, and effective lighting. Additionally, ADUs exceeding 620 square feet typically must include solar photovoltaic (PV) systems designed to offset their electricity usage, while smaller units may be exempt. Newly built ADUs are also required to be “Energy Storage System (ESS) ready,” meaning they must have infrastructure capable of accommodating future energy storage installations. To ensure compliance and integration of these requirements, consulting with La Mesa’s Building Division is recommended during the planning phase of your ADU project.

In La Mesa, the timeline for obtaining a building permit for an Accessory Dwelling Unit (ADU) generally averages around eight months from the initial application submission, accounting for plan reviews, corrections, and administrative processes. However, state law requires the city to either approve or deny a complete ADU application within 60 calendar days. To streamline and expedite the permitting process, La Mesa offers pre-approved ADU plans, potentially reducing the review time significantly. For detailed information on using these pre-approved plans or to clarify the permitting process, it is recommended to contact the City of La Mesa’s Planning Division directly.

In La Mesa, obtaining a permit for an Accessory Dwelling Unit (ADU) involves selecting from the city’s pre-approved ADU plans, available upon request from the Building Division. After choosing an appropriate plan, homeowners must prepare a detailed site plan and any required supplemental documents. These materials are then submitted through La Mesa’s MaintStar Permitting Portal. Once submitted, the city reviews the application, typically making a decision within 60 calendar days. Plan review fees are assessed based on factors like the ADU’s size and configuration. For personalized assistance and clarification of the permitting process, consulting directly with the City of La Mesa’s Planning Division is highly recommended.