Below are the common questions we hear on San Diego ADU regulations, cost, financing, timelines, working with Snap ADU, pre-approved plans, rentals & investments and more. Contact us to talk about specifics of your ADU project.

How large an ADU can I build?

State law allows you to build up to a 1200 sqft detached ADU that is 24′ tall without any local discretionary approvals. If a local municipality creates their own ADU ordinance, they must still permit an ADU of up to 850 sqft, or 1,000 sqft for an ADU that contains more than one bedroom. Attached ADUs cannot exceed 50% of floor area of the main residence.

How many ADUs can I build?

New state laws permit two ADUs on a single family zoned property… one full Accessory Dwelling Unit (ADU) and one Junior Accessory Dwelling Unit (JADU).

What is a Junior ADU?

A Junior Accessory Dwelling Unit (JADU) is defined as a complete independent living facility not to exceed 500 sqft in size and contained entirely within an existing or proposed single family home (think garage or spare bedroom). A JADU must have a separate exterior access, as well as a full bathroom and efficiency kitchen. The kitchen must have a cooking facility with appliances, a food preparation counter, and storage cabinets.

Sometimes we are asked about opting for a “wet bar” instead, which could then prevent a living space from being deemed a JADU. Rules will vary by jurisdiction, but the County of San Diego specifies that a wet bar may not have more than 10′ of cabinets in total length, a single-basin sink of not more than 18″ wide, a fridge of max capacity <=5 cubic feet, no gas or 220 volt AC power outlets in vicinity, and so long as the room “is not designed so that it could easily result in an unpermitted ADU.”

What is the minimum lot size for an ADU?

There are no minimum lot sizes for accessory dwelling units per California state code. Even if there is a coverage ratio maxed out on your property, you are still allowed to build at least an 800 sqft ADU.

Where on my lot can I build an ADU?

Per state law, setbacks for new ADUs have been reduced to 4′ for side and rear yards; some cities, such as City of San Diego, have set 0′ setbacks on the side and rear yards. Also, no setbacks are required if an existing and permitted accessory structure is being converted. You can even remove an existing structure (like an old garage) and replace it with a new ADU that matches the old footprint, even if the old structure had pre-existing reduced setbacks. Any new addition must comply with setbacks, with exception of up to a 30′ encroachment (e.g. above a garage that is at the lot line).

Note that if you choose to build directly up to the setback, there is more of a risk that the city inspector may require a survey. To reduce this risk, we advise leaving an additional 18″ buffer on all required setbacks when possible.

Some municipalities have minimum building setbacks, meaning the ADU must be a minimum distance from the primary residence; state guidance defers to local regulations in this case, and typical is 5 to 10 feet (though some cities, including San Diego, do not list a minimum).

Can I build an ADU in my front yard?

Yes, you can build an ADU in your front yard if it complies with underlying setbacks for your lot. However, the state laws have not reduced setbacks for the front yard, only for the sides and rear.

What’s the most advantageous size to build?

If your ADU is under 500 sqft, it will not require civil engineering review (stormwater, catch basins etc). If your ADU is under 750 sqft, you will not incur impact fees (except for the school fees which are still due even after the new regulations). Our standard 1BR and 2BR designs are under 500 sqft and 750 sqft to help you avoid those additional costs (typically $3-5K). Use our plan search to find floor plans at the size you want.

Can I convert or attach to an existing structure (old shed / garage / outbuilding)?

Yes. Though from a feasibility standpoint, starting from scratch will often be easier and cheaper. Trying to tie into an existing outbuilding can be problematic, especially when it comes to footings and having proper compaction. Grading work done decades prior is not up to par with current standards. When we dig the footings for the new structure up against the existing, often we cannot get compaction and are exposed to settlement issues.

If I have an empty lot, can I build an ADU first and then build a house later?

Yes. Some folks might want to start out with a smaller home, build some equity, then later build another larger home on the same lot and rent out the smaller one. An ADU is a designation that can’t exist by itself – there must also be a primary residence – so the initial home will be considered the primary residence. Then once you build the second larger home, you would then “convert” the status of the original building to an ADU. This means you would need to ensure the first structure you build (what you would later call the ADU) will conform to both the requirements for a primary dwelling AND the requirements for an ADU. For instance, there are typically minimum sizes for a single-family dwelling unit based on the number of bedrooms, there may be minimum widths etc. These requirements will vary by municipality and we can help you determine what requirements must be met (or you can reach out to your building department directly).

Could I build an attached ADU and a JADU at the same time?

Yes, there is a workaround. A JADU has to be contained within the existing single family home. You could expand the primary residence with a room addition or a garage and simultaneously build an attached ADU over the addition. Then you could convert the garage / room addition into the JADU after the addition has been completed. Note that the setbacks for a garage would be the underlying setbacks for the property, not reduced ADU setbacks, which will vary by municipality.

How much will it cost to build a standalone ADU?

As a good rule of thumb, figure on $275-350/sqft for all-in ADU project costs… a 750 sqft 2BR/1BA ADU would typically cost around $215K to build, plus $20K for typical sitework, $8K for design, $8K for permitting costs to city. Read more about ADU costs.

How much will it cost to convert my garage into an ADU?

The cost would be around $90-100K for a standard garage conversion project of about 400 sqft.

What are the fees?

While many ADU fees have been waived, several still apply:

  • Impact fees: There are no impact fees for ADUs <750 sqft. Impact fees for ADUs >750 sqft are proportional to size of the ADU in relation to the primary dwelling unit (typically $3-5K).
  • Sewer: Connection fees are usually $2-4K, with recurring fees thereafter of about $1K/year. If your property is on septic, read more on our septic blog post.
  • School: Usually $4/sqft, so $2-5K
How does Snap ADU pricing work?

We will give you a high-level estimate in our first phone call based on your description of the project and your site. From there, we would present you with a proposal to proceed with Phase 1 (site plan & feasibility study). The proposal would include your expected price for each phase of the project, including design, sitework, and construction. As we work through the ADU location & design with you in Phase 1 & Phase 2 (floor plan & elevations), we will keep track of any significant cost implications stemming from your decisions.

Phase 3 is to produce a set of construction drawings for submission to the city. After we get comments from the city, we can provide a Guaranteed Max Construction Estimate (Gmax), which includes all construction materials  + labor. We will also provide a standard finish package price so you have an all-in cost to build your ADU. Your final finish material cost will depend on your actual selections. We aim to have no surprises by this point, since we keep you apprised of approximate cost throughout the design process.

Can you provide a price off of plans?

Unfortunately we no longer bid out plans that we have not designed in-house. We can work with clients to customize our plans to create something that will work for their property.

Can I provide my own finish materials to save money?

You can, but we typically don’t find clients can save a lot of money by doing so. We have trade agreements in place with suppliers, which help us provide our clients very competitive pricing on finish items – often at the same or better pricing than could be found elsewhere. Additionally, we have already screened materials to ensure the specifications will work together. However, if you want to provide your own finish materials, that is something we accommodate during the Selection process. You can either provide the items yourself, or work with our vendors to source custom materials.

What are financing options?

We work with several providers who can help you navigate financing options to narrow your choices and determine which path is best for you. Check out an overview of ADU Financing Options.

Do you work with construction financing?

Yes, we work with you and your lender to ensure you have the required plans, scope of work, and budget required to submit for loan documentation. If you don’t already have a lender, we are happy to put you in touch with some contacts and help you through that process.

Can potential income of an ADU be used to qualify for a higher loan value?

Yes, this is possible. The Fannie Mae Homestyle Conventional Renovation loan program can be used for purchase of a property + construction of a detached ADU. The loan amount may be based on the future value of the home, i.e. after adding the ADU. The max loan amount is $753,250 (Fannie Mae limit for 2021). Investment properties can be up to 85% financed, while primary residences may be up to 97% financed. Here’s an example of “maxing out” that loan potential while building an ADU:

  • To max out the loan value of $753K, we’d be looking for a property with a future value of ~$886K (=$753K/85%)… you could go over that, but would have to put in more cash
  • Let’s say you choose an ADU that has all-in costs of ~$253K
  • That leaves about $500K for the purchase of the property (=$753K-253K), if the investor didn’t want to pay for any construction costs out of pocket
  • The investor would be responsible for a down payment of ~$133K (=15%*$886K)
How much detail do I need to have for the lender in order to get construction financing?

In our experience, we’ve found it to be sufficient to produce an intended floor plan and elevations, plus scope of work along with a budget that specifies the full construction costs by trade (framing, plumbing, electrical, insulation, sheetrock, etc). If a lender has worked with the contractor in the past, it can be a smoother process since the lender is familiar with the documentation & work of the builder. If you are looking for a property to construct an ADU on, we suggest asking the seller for an “extended due diligence period” of 75-90 days if possible. This allows you more time to research the feasibility of the project you intend to do (e.g. complete a feasibility report to understand any special site requirements that may affect project cost). After you submit the plans & budget to the lender, they will then order an appraisal, which will take into account the value of the “future state” of the property.

How long does the whole process take?

The entire process from signing a proposal to moving into an ADU takes 7-12 months.

  • PLANS & ENGINEERING: 6-10 weeks. Once the proposal is signed, we start designing your unit. We incorporate your needs into the design and check the plan against costs to ensure we deliver a great design within budget.
  • PERMITTING: 12-20 weeks. 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 & processes.
  • CONSTRUCTION: 14-18 weeks. Once we have permits, construction can typically start moving within a week. We handle the entire process, all the way to the final punch list with you to make sure your ADU meets your expectations.
How long is the approval process with the city?

Cities must act on an application for an ADU within 60 days of receiving the application in cases where there is an existing single family dwelling on the lot.

What factors will most affect the timeline?

Permitting with the city still takes a big chunk of time. The build-out is another large chunk of time. It’s a process that includes hundreds of decisions and to-dos, so even losing half a day on tasks can add up significantly. This is why we manage all our projects using BuilderTrend to communicate seamlessly with the client, vendors, subcontractors, and within our team.

Do you measure my site remotely?

Yes, when we move forward on your project, the first step is to assess the existing conditions of the property. We work with a provider that licenses a large data set that includes lot dimensions, land use, lot square footage, building square footage, zoning and more. This is cross-referenced with plot plan information and several different sources of satellite imagery to ensure accurate lot dimensions. When matched up with ADU regulations for your lot, this enables sufficient accuracy for us to position a chosen ADU floor plan on your site plan.

Do I need a survey for my ADU?

Maybe. Unfortunately there is not a one size fits all answer, since the need for a survey is very dependent upon the site conditions, local codes, and the building inspector. Most cities do not require a survey for an ADU, though the final decision is up to the inspector. We do our best to reduce the likelihood of needing a survey. Read more about how we work to reduce the need for an ADU survey and about the cases when it may be prudent to go ahead with a survey even though it is not required.

Do you provide free consultations?

Yes, we are happy to answer feasibility questions, provide ballpark estimates, and get into details quickly about your property specifics so you can decide if an ADU project is right for you and, more specifically, if you’d like to work with us. Contact us to get started.

What is your typical process for working with a new customer?

We get into the details with you right away to make sure your project is feasible and that your vision is aligned with your budget. Read about our overall process from the time we first interact to the time we hand you the keys. Also read about our user-friendly interface, BuilderTrend, where we manage your entire project.

What work does SnapADU do in-house?

We are a general contractor and provide a design/build service, meaning you can work with us for your entire project. We will be on point for getting the job done during design, permitting and in the field. We subcontract out trades like concrete, framing, drywall, plumbing, electrical, HVAC, tile & stucco. We also partner with select septic companies, geotechnical engineers, civil engineers, and structural engineers for the site planning phase of the work. All the rest of the work is done in-house, see our team here.

Do I need to have plans before I start with SnapADU?

No, in fact we offer the most competitive pricing if you pick from our standard plans, or work with us to customize an existing plan to suit your needs. You can also provide us with a sketch of your ideas or your “wish list” and we will design something custom for you.

What areas do you serve?

We build ADUs throughout San Diego, including Oceanside, Carlsbad, Encinitas, Vista, San Marcos, Escondido, Cardiff, Solana Beach, Del Mar, Carmel Valley, Rancho Santa Fe, Rancho Bernardo, Poway, San Clemente, Fallbrook, Bonsall and surrounding areas.

What construction type does SnapADU use?

Our ADUs are “stick built” construction and are not mobile or manufactured homes. All of our ADUs are built on site, though we utilize some offsite processes that improve our quality control and timeline.

Are you the same as Moore Construction?

Yes, SnapADU is affiliated with Moore Construction, an experienced general contractor that historically specialized in custom homes and renovation in North County San Diego. We’ve designed SnapADU as a standalone company & general contractor to meet the need for economical, efficient, and attractive stick built ADUs.

Does your work come with a warranty?

Yes, we provide a 2 year warranty for work performed as part of our construction agreement. This warranty is against any cosmetic defects not arising from normal wear & tear or due to the neglect of the owner to properly maintain the home. We also provide a 10 year warranty against any structural defects arising from a failure on our part to adhere to approved plans & specifications.

A soils report is an optional step in most jurisdictions. Declining a soils report means that no soils compaction testing will be performed by a Geotechnical Engineer, and the ADU will be built to the most stringent UBC design standards & thresholds. In such cases when a soils report is declined, SnapADU shall not be held responsible for any issues related to insufficient soils conditions. A soils report can be ordered for an additional ~$5K.

What are “pre-approved” or “permit-ready” ADU plans?

The County of San Diego and Encinitas have made several ADU plans available to the public. Encinitas calls theirs the Permit-Ready Accessory Dwelling Unit (PRADU) Program. All of their plans are searchable by size on our ADU Plans+Pricing page so you can consider them alongside other options.

Will using pre-approved plans save money & time?

Sometimes. If you can use a plan exactly as-is, you may not need to pay for architectural plans. You will also still need a site plan along with Title 24 calculations. And lastly, since most of the costs of your ADU project are in the actual sitework and build-out (not the design phase), the few thousand you may save on plans may vanish because of higher build costs. We’ve put together a guide so you can assess whether a pre-approved plan might work best for your ADU.

Can I use an ADU for short term rental?

Any newly constructed ADUs cannot be rented for less than 30 days. This is a state-wide requirement that cities cannot overrule. A city cannot issue a building permit until you have signed a covenant that agrees you will not rent the ADU for less than 30 days. You do have the option of moving into the ADU and renting out your primary residence as a short-term rental.

Can I add ADUs to multifamily property?

Yes. Per state ADU code, if you have a structure of two or more residential dwellings that are attached to each other (e.g. a duplex) and in a residential zone, you may add two detached ADUs. The new standalone structure has a 16’ height limit with 4’ rear/side setbacks (the city-specific ADU code may be more lenient). You can also convert accessory space within the existing structure to an ADU… one per every four existing residential units. You can convert portions of space that are not used as livable space, such as storage rooms, garages, carports, mechanical rooms, attics or basements.

We’ve learned that in jurisdictions like Oceanside, the multi-family provision only applies to properties developed with existing multi-family units. So if the property only has a single family residence on the property – even if the area is zoned for duplexes – the owner can only build one ADU.

Is there an owner occupancy requirement?

There is a five year moratorium on owner-occupancy requirements… you can lease out both your home and ADU until 2030. Read more about owner occupancy requirements here.

Do I need to add parking for the ADU?

ADUs do not require parking if they are within a half mile walking distance of public transit or created within an existing space in your house or an accessory structure, like a garage or carport. Additionally, no replacement parking is required for the main residence when a garage or carport is demolished or converted to create an ADU. Otherwise, parking requirements for ADUs are one parking space per unit or per bedroom (whichever is less). JADUs do not require parking.

What about utilities?

Typically, no new utilities or meters are needed. You can connect “behind curb” on your private property. We can install a private, sub-meter to read usage if desired. If you would like to know the utility usage, a cost-effective option is to install sub-meter that can monitor the water, electric and gas usage of the ADU only.

What if my property is on septic?

If your property is on a septic system, we recommend a “Phase 0” where your system is mapped and assessed to determine capacity. In many cases, a new system will be required and, if so, we want to make sure and factor that in to your broader project costs so you can design to your budget. Read more about septic systems for ADUs.

What about my HOA?

Neither HOAs (Home Owners Associations) nor property CC&Rs (Covenants, Conditions and Restrictions) can “reasonably prohibit” development of an ADU or JADU. However, they can make it more time consuming and expensive for you, and in some cities HOAs have won against homeowners.

Some cities, such as Poway and Rancho Santa Fe, also have requirements that the architectural features of the ADU match the main house. We can quote out any upgrades this might entail, for instance upgrading to a tile roof or board and batten siding.

Our approach is to prepare our Feasibility Report, which includes a site plan, floor plan, and elevations, which includes callouts on materials to be used (typically to match existing house). In some cases this is sufficient for the HOA. In other cases, they may require full construction drawings. We usually advise the client to submit to the HOA and for permits concurrently, and address any design changes called out by the HOA during the plan revision process that occurs with the municipality.

Read more about HOAs and ADUs on our blog.

What if I own a condo and want to build an ADU in my portion of the property?

These are very sticky situations where it’s legally murky as to what is allowed. Legally you can build up to two ADUs on a multifamily parcel. The question is whether the other condo owners are also OK with it, since they likely collectively own the common spaces. Building an ADU would likely require the various owners in the HOA to authorize the ADU in the common area, unless there is something else written in the Covenants, Conditions & Restrictions (CCRs).

Do I need to install solar on my ADU?

Solar is mandatory for all detached ADUs that do not currently have a solar array on the main home. Typically a 1.44KW system is the minimum size and will run about $10K. There is some upside here, as in 2021, solar panels allow for taking a federal tax credit of 26%.

Can I sell the ADU separately from my house?

An ADU may be rented out but is not intended or allowed for sale separate from the primary residence at this time.

Does an ADU have a separate address?

Yes, an ADU is typically designated with a separate address for fire safety reasons (so the fire department would know where to go).

Does adding an ADU increase my property taxes?

Yes, the state will conduct a “blended assessment” to determine your taxes. This means the base value of the existing house will stay the same, and your ADU’s additional value will be added to the existing home’s value. Once this new assessed value for the ADU + property is set, the property value will then be taxed at 1% and up to 2% annually. This is generally an increase of $1-2K a year for a typical ADU.

California has a standard guide that explains “cost factors” whereby the newly added unit is assessed for various components, e.g. living space, garages, deck etc. A multiple is calculated and used to come up with a new value for the ADU, which is added to the existing tax base. Typically assessments value the improvements at “wholesale” costs, e.g. considerably lower than it actually cost to build the ADU. It takes about a year to run through the process before the new assessment becomes active.

Can I add an ADU in a Coastal Zone?

Probably yes. Getting a permit for an ADU in the coastal zone is becoming much more likely, though the process may take time. Usually if there is a Local Coastal Program (LCP) in place by the city to handle low impact Coastal Commission projects, then it can be handled by the LCP at the city level. LCPs are catching up to state ADU legislation in favor of ADUs, though in some areas, restrictions are still more stringent (e.g. bluff top size, hillside overlay zone, wildland urban interface etc). Read much more in our blog about Granny Flats in The Coastal Zone.

What about existing “illegal” or non-permitted ADUs or Junior ADUs on my property?

When you build your new ADU, we can at the same time handle permitting for any “illegal” ADUs on the property. The process is similar to bringing an illegal addition into compliance. It would require drawing a plan for the existing structure (typically $2000-3000), sending it to plan check at the city (planning, building, and fire), potentially conducting an exploratory phase where walls are opened up for inspection with the city (typically no more than $1000-2000 for opening walls and repairing them), addressing anything in the structure that is not within compliance (cost will of course depend on what’s going on with your structure), and paying for any permits (typically $1000). Any tenants in your existing ADU likely will not need to vacate during this process.

What advice would you give a customer looking to hire an ADU contractor?

Consider the visibility you will have into the project. How does the company handle project management? What tools will enable you to stay up to date on progress? How easy is it to work with the company on things like payments and material selections? Pick someone you trust & will be excited to interact with about your project on a regular basis… it should be a pleasure to discuss your project, not a chore. It’s also important to engage a contractor early on to provide cost analysis and make sure you are designing within your budget.