ADU Basics

Learn About Building an ADU

Just starting to think about building an accessory dwelling unit (ADU) on your property in San Diego? You probably have a lot of questions…

What is an ADU? Is an ADU the same thing as a companion unit, granny flat, casita, guest house or in-law suite? What and where can I build on my property? How do I start in the process? Do I need to talk to an architect or a contractor first, or maybe start with financing? How much will it all cost?

We’re happy to help you get up to speed so you can decide if building an ADU in San Diego is right for you.

WHAT IS AN ADU?

The definition of an accessory dwelling unit (ADU) is a detached or attached dwelling unit that provides complete independent living facilities - including a kitchen and a bath - on the same parcel as a residential dwelling. ADU, granny flat, companion unit, casita, guest house, granny cottage, secondary living unit, mother-in-law apartment, second dwelling unit, in law suite, carriage house, au-pair suite... you may hear any of these terms used interchangeably for an accessory dwelling unit (sometimes mistakenly called an "additional dwelling unit," "auxiliary dwelling unit" or "accessible dwelling unit"... we like to think they're awesome dwelling units).

What is a Junior ADU?

Junior ADUs (JADUs) offer an option to add another unit (in addition to an ADU) within your existing home. JADUs must be contained within an existing or proposed single family home (think garage or spare bedroom), under 500sqft (you can add on up to 150 sqft to get to 500), and have a full bathroom and efficiency kitchen (appliances + cabinets).

What about Tiny Homes as ADUs?

Tiny homes have recently been classified as a type of ADU in San Diego – you can have a detached tiny home (150-430 sqft in size, licensed by the DMV) as your ADU in your back yard. Note that this is not in addition to having an ADU; the tiny home is classified as the ADU. Tiny Homes must be connected to all utilities and sit on a concrete pad, which means the all-in costs of using a tiny home for your ADU often end up looking very similar to a permanent ADU.

What are Guest Living Quarters?

ADUs are also sometimes called guest houses, though there is a technical definition of “guest living quarters,” which are different than ADUs. Guest Living Quarters are only for use by those employed on the premises or for temporary use by guests and may not be rented out. Guest Living Quarters may not have kitchens or laundry facilities. In some municipalities, guest living quarters can co-exist with an ADU.

Where can you construct or convert ADUs?

ADUs can take many different forms, either within or attached to your existing residence, or as standalone structures.

TYPES OF CONVERSIONS

New Stand Alone Unit

Looking for ADU floor plans? Head over to see all our standard floor plans. We can also create a modified design for you from any of our plans.

Addition or Expansion

We offer pre-selected design packages to choose from so you can easily find a cohesive look that’s perfect for your ADU.

Space Conversion

Learn about included elements & features in our standard proposals & construction bids (spoiler alert: we included it all + the kitchen sink).

WHY BUILD AN ADU IN LOS ANGELES?

Los Angeles homeowners build ADUs for many different reasons. Whether you’re thinking about moving part of your family to the ADU or looking for extra income, ADUs are flexible additions that can afford your family more options on your existing property… while adding value to the property when you eventually sell (or even sooner if you decide to refinance).

FLOOR PLANS

Looking for ADU floor plans? Head over to see all our standard floor plans. We can also create a modified design for you from any of our plans.

INTERIOR DESIGN

We offer pre-selected design packages to choose from so you can easily find a cohesive look that’s perfect for your ADU.

HOME FEATURES

Learn about included elements & features in our standard proposals & construction bids (spoiler alert: we included it all + the kitchen sink).

ADU Regulations To Know

SIZE

Zero minimum lot size requirement in CA. Local municipalities may pass additional regulations, but must allow a minimum 850 sqft 1BR or 1000 sqft 2BR+ with only 4′ side and rear setbacks.

APPLICATION REVIEW

Building departments have been required to act on any ADU application within 60 days (and we see most acting much sooner). This limit used to be 120 days.

PARKING

Most parking requirements have been waived (none required if within 1/2 mile from public transit), or are readily addressed (ADU attached to the primary dwelling doesn’t require parking!).

OWNERS

Zero minimum lot size requirement in CA. Local municipalities may pass additional regulations, but must allow a minimum 850 sqft 1BR or 1000 sqft 2BR+ with only 4′ side and rear setbacks.

FEES

Building departments have been required to act on any ADU application within 60 days (and we see most acting much sooner). This limit used to be 120 days.

HOAS

Most parking requirements have been waived (none required if within 1/2 mile from public transit), or are readily addressed (ADU attached to the primary dwelling doesn’t require parking!).

CAN I BUILD AN ADU ON MY PROPERTY?

While the new statewide ADU laws have made it much easier to add an ADU in San Diego, each municipality operates with a different set of requirements. Knowing how to scope & present your ADU project can mean the difference between a quick permit issuance and a drawn-out, costly process of resubmittals and additional fees.

We are constantly working to better understand ADU regulations in Greater San Diego and how to help our clients effectively navigate them. Part of the value we add to your project is the experience of bringing many ADUs through the permitting & building process.

Click below to investigate the most important parts of your city's ADU regulations. If you work with SnapADU, our feasibility study assesses all of the local and state rules that apply to your property & project.

HOW DO I START TO BUILD AN ADU IN SAN DIEGO?

With all the moving parts involved with building an ADU, it's tough to know where to start. With an architect? A contractor? Maybe a lender? At the city planning office? Or with an ADU consultant? At Snap ADU by Moore Construction, we're excited to dig into all of these aspects with you and act as the ADU builder and "quarterback" on your project. We have the in-house expertise and established partnerships to guide you through the ADU building process and make it all happen in a snap.

Put simply, we like being involved in all aspects of your ADU project to make sure it goes well, whether you are going full custom or working with a standard plan. We offer our own value-engineered floor plans & designs, but if you have your own architect that's OK, too... or we can also start from scratch with you on designing a custom plan. We also regularly work with the San Diego County Standard ADU Building Plans and the Encinitas PRADU Building Plans (and you'll want to read more about considerations for using county standard plans on our FAQ page). If you will be getting financing, we want to talk to your lender right away to make sure you will have exactly what is required.

THE PROCESS FOR BUILDING AN ADU

FREE

CONSULTATION

We will want to learn about your site location & requirements, building size & specifications, as well as your vision for the finishes in the unit. We’ll want to know which ADU plan is closest to what you’re looking for as a starting place for the design. From there, we can provide high-level feedback on feasibility & cost. Timing: 1-2 days

STEP 1

SIGN

PROPOSAL

STEP 2

SITE

PLANS

The Site Plan & Feasibility Report confirms what the building envelope will be for your ADU given the local requirements and your site conditions. We can also modify our plans based on your input & requirements. We ask for a mark-up with your changes to ensure we are on the same page and move swiftly through the design phase. Timing: 8-10 weeks (standard plan), 10-14 weeks (modified plan)

STEP 3

CONSTRUCTION

DOCUMENTS

Once the floor plan & elevations are approved, we will produce a full set of architectural drawings along with required calculations & reports for submission to the city for permits. Concurrently, we will refine your construction estimate, working with you to ensure the design will fall within your budget. Timing: 4-6 weeks

STEP 4

DESIGN

SELECTIONS

We like to have our clients make interior & exterior design selections early in the process to ensure we can keep your project on time and on budget. While the architect is working on construction drawings, you’ll make your design choices. Timing: 2-4 weeks (concurrent with other phases)

STEP 5

FINANCING

PROJECT

You may want to pursue financing options, such as using a line of credit or construction loan. We ensure you have the required plans, scope of work, and budget to submit to a lender for any loan requirements. We can also make recommendations for lenders who work with construction loans for ADUs. Timing: 6-12 weeks (concurrent with other phases)

STEP 6

SUBMITTING

PERMITS

We submit plans to the city & pull required permits. We work closely with the building department to ensure submitted construction plans move as swiftly as possible through plan review & permitting processes. After we receive revisions from the city, we also produce your guaranteed price maximum for construction. Timing: 12-18 weeks

STEP 7

BUILD