Frequently Asked Questions

Most cities throughout San Diego County allow up to 1200 sqft, including the city of San Diego. However, there are some exceptions. For example, Escondido only allows up to 1,000 sqft, and Poway allows up to 1,500 sqft in some cases. Read our guide to ADU sizes and see city-by-city ADU regulations.

Many jurisdictions allow two story ADUs including the City of San Diego and the County of San Diego. Even in jurisdictions that do not typically allow 2 story ADUs, California state law still permit a 2 story ADU up to 18 feet tall if the property is located within a 1/2 mile of a major public transit stop.

However, what you can actually build depends on several factors, including local zoning height limits, setback requirements, transit proximity, fire codes, and even how your city measures building height.

Check out our two story ADU guide to learn more.

Per California state law, setbacks for new ADUs have been reduced to 4′ for side and rear yards. The City of San Diego went even further and has established 0′ setbacks on the side and rear yards for single-story ADUs. 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.

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 typically required building separation is 5 to 10 feet. Though some cities do not list a minimum, fire code is still a consideration. This is why we usually hold at least 6′ from existing structures. Read more about ADU setbacks.

Yes, you can generally build an ADU in your front yard if it complies with underlying setbacks for your lot. A local agency may still apply front yard setbacks for ADUs.

However, front yard setbacks cannot preclude an ADU of at least 800 square feet and must not unduly constrain the creation of all types of ADUs (Gov. Code, § 65852.2, subd. (c) and (e)). So, if you are looking to build an ADU under 800 square feet, you can build in the front yard encroaching into the front yard setbacks.

Read more about ADU setbacks.

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 statewide exemption ADU in California.

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.

Typically, cities have accepted showing replacement parking in the driveway. We can also convert existing landscaping to parking, so long as this parking does not exceed the lot coverage allowed per the zoning.

No, an HOA cannot stop you from building an ADU. However, HOAs can impose reasonable restrictions on ADUs such as architectural standards. SnapADU has built many ADUs in HOAs including very stringent HOAs such as Rancho Santa Fe.

See our HOA ADU projects, and read more about building an ADU in an HOA.

Yes, you can build an ADU in a historic district or on a property subject to historic preservation, such as under the Mills Act. While local agencies may impose standards to protect historic resources, these standards must be objective and cannot overly burden the creation of ADUs. California State ADU Law ensures that historic preservation requirements do not prevent compliant ADU projects. Read more about ADUs in historic districts.

Yes, in general, you can build an ADU in most of the coastal zone. However, depending on the jurisdiction there may be some added time and expense. Read more about building an ADU in the Coastal Zone.

No, a junior accessory dwelling unit (JADU) must be created from existing space within the primary dwelling unit. A JADU cannot be built as part of a detached ADU.

Note that a JADU is only possible on a single family lot, as JADUs are not allowed on multifamily lots (which already typically allow two ADUs – check out city ADU regulations pages for rules by municipality).

Also note that, until December of 2023, the City of San Diego did permit a JADU to be attached to an ADU. They closed that option as part of the Housing Action Plan 2.0.

Until recently, an ADU could not be sold separately from the primary residence due to California state law. However, AB 1033 lets cities and counties decide whether to offer the option of condo conversion in their jurisdiction.

As of 2026, a few jurisdictions including the City of San Diego and the County of San Diego have adopted this locally. Read more about AB 1033 and selling ADUs.

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. Read more about if you can build an ADU before the main home.

When you build your new ADU, you may have to address permitting for any “illegal” or unpermitted ADUs on the property. The process is similar to bringing an illegal addition into compliance – read more from City of San Diego about How to Obtain a Permit to Legalize Unpermitted ADUs. At a high level, it would require drawing a plan for the existing structure (typically $3000-5000), 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 $1-2K).

ADU permit fees greatly depend on the jurisdiction and ADU size. They can range from a few thousand dollars to $30K+. For instance, while permit fees in Encinitas are generally $2-4/SF, permit fees in San Diego are closer to $26-28/SF (though quite a bit less for ADUs under 500 SF at $13/SF average). Read more about the different types of permit fees when building an ADU.

We will give you a high-level estimate in our initial discovery meeting based on your description of the project and your site. If we determine your project is a fit, we conduct a Virtual Site Visit and create a Feasibility SnapShot & proposal that includes your expected price for each phase of the project, including design, sitework, and construction. If you do move forward with SnapADU, we finalize your ADU build price during our first step of Feasibility & Design so that you know the full cost of you ADU upfront; we absorb the risk of labor & material price fluctuations. Read our blog on ADU pricing to understand how we work hard to refine your budget so we minimize surprises over the entire process.

You can provide your own finish materials, 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.

For homeowners that want to handle all finish work themselves including installation, we offer a Tape & Texture (TNT) option. Also known as a “white box” approach, we can take your project all the way from design to drywall, then you can complete the finish work as you see fit. TNT will save $40-90K between labor & materials depending on the size project. Read more about Tape & Texture.

Some factors that can quickly add cost to an ADU project include long utility runs, slope / retaining walls, soils export & grading, difficult site access, and fire requirements such as fire sprinklers or creating fire access. Read more about Sitework & Utility Costs.

Yes, adding an ADU does increase property taxes. The state will conduct a “blended assessment” to determine the tax increase. 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 1-2% annually. This is generally an increase of $2-4K in taxes a year for a typical ADU. Learn more about ADU property taxes.

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.

Yes, we offer free discovery meetings 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. The Feasibility Snapshot — a paid assessment ($475, credited toward your project) that includes a 15-page deliverable, site analysis, and a formal proposal — follows for those ready to move forward.

Contact us to get started on the free discovery process.

When we discuss your project, one of the first steps is to assess the existing conditions of the property. We work with a provider that licenses a large data set that includes lot dimensions, topography, 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 for the purposes of a proposal.

When you decide to move forward, the first part of our project with you will be to verify all of our assumptions by going on-site to measure existing utilities, assess required upgrades, and ensure that the site assumptions we made were accurate. We will also refine your site plan, floor plan, elevations, and electrical plan based on all these inputs. You will review and sign off at this phase to lock in your pricing and authorize us to move on to your full set of construction documents for the city.

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.

Yes! We offer custom, standard, and semi-custom plans. Read more about custom ADUs and custom ADU floor plans, and check out all our standard floor plans as a jumping off point.

Our primary focus is on design-build projects, providing an integrated, end-to-end experience for our clients. While we don’t exclusively offer design & permitting services, if you’re open to considering the complete design-build approach, we’re here to guide you every step of the way. And why choose a design-build general contractor like SnapADU over separate teams of professionals? Here’s a snapshot of the benefits:

• Accountability: Our singular focus on design-build ensures seamless project execution. We are entirely accountable, aligning with the commitments made during the feasibility study.
• Transparent Budgeting: Our approach centers around clear budgeting. We provide an unambiguous view of the complete costs right from the outset.
• Guaranteed Price: With SnapADU, you get a fixed build price. This ensures budget predictability with no surprises.
• Efficiency: Our in-house permitting team ensures that the project moves swiftly and efficiently, eliminating potential delays that can arise from multiple handoffs.
• Quality: A collaborative, unified team means that the end result will be of the highest standard.
• Cost Savings: A significant number of projects encounter cities that may misinterpret ADU regulations, leading to unnecessary costs. Our seasoned team is well-equipped to advocate for you, ensuring you aren’t paying more than you need to.

We are a licensed general contractor and provide a design/build service, meaning you work with us for your entire project and we are fully accountable. 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 by our team, including design & permitting.

Our ADUs are “stick built” construction and are not prefab ADUs, mobile or manufactured homes. All of our ADUs are built on site using conventional framing methods, though we utilize some offsite processes that improve our quality control and timeline. We regularly evaluate new technology to make sure we are offering a competitive product.

We build ADUs throughout Greater San Diego, including Oceanside, Carlsbad, Encinitas, Vista, San Marcos, Escondido, Solana Beach, Del Mar, Poway, La Mesa, El Cajon, Chula Vista and surrounding areas. See our service area map.

Yes, SnapADU provides comprehensive warranties as part of our construction agreement. Our commitment includes:

• 1-year Full-Service Warranty on all workmanship and materials we manage or procure, ensuring adherence to the NAHB Residential Construction Performance Guidelines – Fifth Edition. This warranty covers defects not caused by normal wear and tear or homeowner neglect.
• 2-year Full MEP Warranty on all mechanical, electrical, and plumbing (MEP) systems, including solar/photovoltaic systems
• 10-year Structural Warranty against structural defects, contingent on our adherence to approved plans and 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 will not be responsible for issues stemming from insufficient soil conditions.

In a world where versatility is often praised, there’s still immense value in specialization. We have made a deliberate decision to focus solely on detached ADU (Accessory Dwelling Unit) design and build for several key reasons:

1. Expertise Through Specialization: By dedicating ourselves exclusively to detached ADUs, we’ve refined our skill set to become true experts in this niche area. This enables us to maintain the highest quality standards and keep up with the latest best practices, ensuring our clients receive nothing but the best. From initial planning and design to the final stages of construction, our in-house team collaborates seamlessly, ensuring a cohesive and efficient project flow.
2. External Elements Can Be Managed Post-Completion: While elements like landscaping, patios, or other auxiliary structures can enhance the overall aesthetic and functionality of a property, they are not integral to the ADU construction process. These components can be executed after our work is done. We’ve found that many homeowners have preferred vendors for such tasks or may even choose to undertake some projects DIY-style. By allowing homeowners the flexibility to manage these elements separately, they often find opportunities for cost savings and personalized touches.
3. Home Additions and Remodels Present Unique Challenges: Working on additions or remodels is fundamentally different from constructing a detached ADU. Such projects require extensive coordination with existing structures and conditions, which can be unpredictable and may lead to extended timelines and unforeseen expenses. Our commitment to transparency, predictability, and excellence means we avoid venturing into areas that could compromise these values.

While there are countless avenues in the world of construction and design, we’ve found our passion and expertise in ADUs — and we’re committed to being the best in this space.

Good ADU contractors have specialized experience with accessory dwelling units, a strong understanding of local regulations, transparent pricing, and a clearly defined process from design through construction. Because ADUs involve unique challenges like permitting, utility coordination, fire requirements, setbacks, and site constraints, it’s important to work with a company that handles ADU projects regularly rather than a general contractor with only occasional ADU experience.

Read more about how to choose the right ADU contractor.

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. We are also seeing some cities enact “queues” for review, especially when they are facing staffing crunches like many industries are right now. We keep our clients updated on what to expect in their city.

In short, the answer is no. State laws passed in 2020 made obtaining a new ADU easier with “ministerial approval,” which refers to a streamlined permit process for development approval involving little or no personal judgment by the public official. The official’s “discretion” on whether to approve the permit has been eliminated, as well as factors such as design features and size. Thus, only the municipal code or state laws will be considered in the approval process. A plan must still be formally submitted to the city and reviewed to confirm the plans adhere to the state and local ADU laws, building code, etc.

There are many factors that add time to an ADU project. Some of the most common factors include:

• City delays (some jurisdictions take longer than others)
• Coastal zones
• HOAs
• Utility Upgrades
• Right of Way Work
• Plan revisions & changes
• Long material lead times

Our comprehensive Feasibility Study covers every aspect necessary for a successful ADU build. This includes a site plan, zoning & code analysis, initial utility assessment, design, renderings, and a detailed budget. We also obtain necessary property reports such as a survey and utility mapping.

A detailed feasibility study is the backbone of a smooth ADU project. It sets expectations early, clarifies the true cost of the build, and prevents surprises during permitting or construction.

Read more about the importance of ADU feasibility studies and everything that is included.

It depends on your city’s requirements, site conditions, and where your ADU will be placed. Some jurisdictions now require a boundary survey for all ADUs, while others leave it up to the building inspector, who may request one even after permitting, causing delays. To avoid surprises, SnapADU includes a basic planimetric/topographic survey in all our projects. If your ADU is within 2 feet of a setback, a boundary survey may also be required. Learn more about ADU survey requirements

Not every ADU project requires a soils report, but there are many instances where one will be needed. These scenarios include:

• Poor soil conditions
• Steep slope
• Jurisdiction requirements

Learn more about soils reports and if one will likely be required for your project in our Guide to Soils Reports for ADUs.

No. Any newly constructed ADUs may only be rented for periods of more than 30 days. This is a state-wide requirement designed to curb the use of ADUs for short-term rental. 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, however, have the option of moving into the ADU and renting out your primary residence as a short-term rental (except in Oceanside, where neither the ADU nor the primary may be used as a short term rental). However, short-term rental rules change frequently and vary by city — verify current local regulations before assuming this exception applies.

Read more about renting out an ADU.

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

Read more about ADU address requirements.

Yes, an ADU will receive a separate electric bill from SDGE. This is because all ADUs must be metered separately for electrical service. Read more about electric panels and service upgrades for ADUs.

Water service can be metered privately by means of a metering device that is located on the ADU. Upon request, SnapADU will provide the preparation to accept a metering device which can be connected to WiFi and monitored remotely on your smartphone or computer. We recommend this product as a WiFi enabled water meter. Learn more about water, gas, and sewer connections for your ADU.

No! Owner occupancy requirements have been permanently banned by the State of California (AB 976), meaning you could add an ADU on a rental property. Read more about owner occupancy requirements here.

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 or up to the number of units existing on the property, capped at 8. You can also convert accessory space within the existing structure to an ADU. Read more about adding ADUs to multifamily properties.

Yes, for many homeowners an ADU can be a strong investment! To assess if an ADU is a good investment for your property, you will want to understand the costs for the size unit you want to build. Then, you will want to understand the anticipated effect of the ADU on the property value and also on the potential rental income for the property.

Our blog on investing in an ADU details all important considerations for determining if an ADU would be a good investment for your property.

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 to pre-approved plans so you can assess whether a pre-approved plan might work best for your ADU.

Generally, no, pre-approved ADUs plans cannot be customized. However, some pre-approved plans such as the ones SnapADU created for the cities of Chula Vista & San Marcos have some set modification options to choose from.

Because of the lack of design flexibility, pre-approved plans are not suitable for every scenario. For instance, pre-approved plans may not work for projects that involve complex site conditions like steep grade or for homeowners that have a very specific architectural vision for their ADU.

Passed in October 2023, AB1332 mandated that every city must accept pre-approved ADU plans and all pre-approved plans must be made publicly available on the city’s website.

However, it’s important to note that as of January 1st, 2026 the new California building code cycle took effect. That means all previously pre-approved ADU plans must now be updated to comply with the latest code requirements. So as of early 2026 there are currently very few truly “off-the-shelf” pre-approved plans that will pass review as-is until cities bring their plans up to code.

We are happy to help realtors evaluate ADU potential for their client’s properties. We also offer a referral program for clients referred to our team. Learn more about our referral program, and also check out our blog on Benefits of ADUs for Real Estate Agents as a great place to start!