ADU Builders in
San Diego, CA

Start with the City of San Diego's ADU and JADU program page and Information Bulletin 400. The city says a building permit is required for every ADU or JADU project.

Homeowner question	Current San Diego check
How large can an ADU be?	San Diego publishes an ADU range of 150 to 1,200 square feet. The viable size still depends on the unit type and site.
How tall can it be?	ADUs must comply with the applicable zone's maximum height. In single-dwelling zones, an ADU may not exceed two stories.
What setbacks apply?	A new detached ADU must meet the zone's front setback. Side and rear rules depend on height, neighboring uses, fire-hazard status, and the property.
Can I use a preapproved plan?	San Diego accepts named local preapproved plans. Applications using them receive a 30-day review, but still need property-specific compliance and a plan-provider license.
Are coastal properties different?	Yes. Confirm the Coastal Overlay Zone and appeal area before relying on the general path. Some projects may need a Coastal Development Permit.

Check the parcel before the plan

Use San Diego's Zoning and Parcel Information Portal to check the base zone, overlays, sustainable-development status, and other mapped conditions. Then confirm the findings with Development Services. A map is a starting point, not a project approval.

The city publishes a front-setback rule for new detached ADUs and more detailed side and rear rules. For example, an ADU taller than 16 feet must observe a four-foot side and rear setback when the neighboring premises are residentially zoned or used only for residences. A four-foot side and rear setback also applies in a Very High Fire Hazard Severity Zone, regardless of structure height.

Treat preapproved plans as a faster plan-review route

San Diego accepts the County of San Diego's standard ADU plans and named plans from Chula Vista and Encinitas. The city says an application using an accepted preapproved plan receives a 30-day review and must still comply with the San Diego Municipal Code.

The plan is not automatically free to use. San Diego directs applicants to the provider for licensing cost. The property still needs site information, utility decisions, and any required coastal, fire, structural, or other review. Compare the plan's fixed assumptions with a custom design before deciding which route saves time or money.

San Diego does not publish one construction price that fits every address. Use the same scope for at least three itemized bids, and do not treat a builder's advertised range as a city-backed estimate.

Scope line	What to compare
Feasibility and design	Survey, zoning and overlays, preapproved or custom plan, architecture, structural work, energy documents, and revisions.
City and agency costs	Plan review, building permit, any coastal review, utility review, school or impact fees, and property-specific charges.
Site and utilities	Access, demolition, grading, drainage, sewer, water, electrical service, trenching, meters, and fire separation.
Construction	Foundation, framing, roof, windows, exterior finish, insulation, mechanical, electrical, plumbing, solar when required, and inspections.
Interior scope	Cabinets, counters, flooring, tile, fixtures, appliances, lighting, paint, and accessibility choices.
Risk allowance	Plan-check corrections, utility upgrades, concealed conditions, coastal or fire requirements, lead times, and written change-order rules.

San Diego says permit fees vary with the project and points applicants to its current construction permit fee schedule. Ask each builder to separate design and engineering, government and utility charges, site work, construction, finishes, exclusions, allowances, and contingency. A lower total is not comparable when it omits work included elsewhere.

The city's current ADU and JADU guidance says there are no exemptions from the building-permit requirement.

• Confirm City of San Diego jurisdiction. A San Diego mailing address may sit outside city boundaries, so identify the permitting agency first.
• Check the parcel. Review the zone, Coastal Overlay Zone, Sustainable Development Area, fire-hazard status, easements, existing structures, and access.
• Choose the ADU type and count. Confirm whether the plan is detached, attached, a conversion, or a JADU, and whether any bonus program is relevant.
• Compare custom and preapproved designs. Use a preapproved plan only when the layout, provider terms, and property conditions fit.
• Resolve site and utility questions. Show utility routes, service capacity, drainage, fire separation, refuse storage, solar requirements, and any coastal work.
• Prepare and submit the permit package. Include the city forms, complete plans, calculations, and property-specific documents required for review.
• Answer comments and complete inspections. Keep correction responsibility clear in the designer and builder scopes, then obtain final approval before occupancy.

What the 30-day review covers

The published 30-day review applies to applications that use an accepted preapproved plan. It is not a promise for the full project. Property research, plan licensing, application preparation, corrections, coastal or utility coordination, permit issuance, construction, inspections, and final approval can add time.

San Diego-specific checks

• Coastal status: Use the city's Coastal Overlay Zone map and confirm whether a Coastal Development Permit or different standards apply.
• Fire conditions: Very High Fire Hazard Severity Zone parcels have a published minimum four-foot side and rear setback for an ADU.
• Parking: San Diego generally does not require parking for new ADUs, but it publishes exceptions for certain Beach Impact Area and bonus-unit situations.
• Rental term: The city says an ADU or JADU may not be rented for fewer than 31 consecutive days.
• Solar: The city says newly constructed, non-manufactured detached ADUs are subject to California Energy Code solar requirements.

Do not base the project on a countywide rent average or a builder example. Use current long-term San Diego leases for units that match the proposed neighborhood, bedrooms, size, privacy, parking, utilities, outdoor space, and condition.

For a conservative model:

• Use the lower end of current comparable leases with terms of at least 31 consecutive days.
• Multiply monthly rent by 12 for annual gross rent.
• Subtract vacancy, maintenance, insurance, utilities paid by the owner, management, and reserves.
• Compare the remaining annual amount with the full project budget, including financing and contingency.

San Diego's public guidance says ADUs and JADUs cannot be used for rentals shorter than 31 consecutive days. Confirm the current rule and any deed restriction, homeowners association requirement, or lender condition before treating rent as project income.

How large can a San Diego ADU be?

The City of San Diego publishes an ADU size range of 150 to 1,200 square feet. The viable size still depends on the unit type, lot, zoning, setbacks, fire conditions, and other property-specific rules.

Does San Diego require a building permit for an ADU?

Yes. The City of San Diego says a building permit is required to create an ADU or JADU and that there are no exemptions. Some coastal projects may also need coastal review.

Do San Diego preapproved ADU plans skip site review?

No. The city says applications using accepted preapproved plans receive a 30-day review, but the project must still comply with the San Diego Municipal Code. Homeowners must also contact the plan provider about licensing cost.

What should I check on a coastal San Diego property?

Use the city's zoning and parcel tools to confirm whether the property is in the Coastal Overlay Zone and whether the location is appealable or non-appealable. The permit path and applicable rules can differ.

What setbacks apply to a San Diego ADU?

A new detached ADU must comply with the zone's front setback. Side and rear rules depend on height, adjacent uses, fire-hazard status, and the site; a four-foot setback applies in several published situations.

How should I budget for a San Diego ADU?

Give at least three builders the same property facts and scope. Compare design, engineering, permits, utilities, site work, construction, finishes, exclusions, allowances, and contingency before relying on a total.

How are the listed San Diego builders selected?

The directory uses public builder-owned evidence that a company serves San Diego and a dated CSLB license check. Inclusion is not an endorsement; homeowners should verify current licenses, insurance, references, scope, and availability.

• City of San Diego ADU and JADU program
• City of San Diego Information Bulletin 400, ADU and JADU regulations
• San Diego Zoning and Parcel Information Portal
• City of San Diego building permit application
• City of San Diego construction permit fee bulletin
• County of San Diego standard ADU plans accepted by the city
• California HCD ADU handbook