Frequently Asked Questions

Many pages on this site feature FAQs – here are all the FAQs together in one place.

How long does construction take?

Traditional construction will take 6-12 months, though this will vary depending on the specifics of the project. Stages of construction include:

  • Site preparation: 1-2 months
  • Foundation: 1 month
  • Walls, roof, doors: 1-2 months
  • Plumbing & electrical: 1-2 months
  • Insulation & drywall: ½-1 month
  • Fixtures & finishes: 1-2 months
  • Final touches: ½-2 months
What do I need to know about becoming a landlord?

Renting an ADU comes with many responsibilities, including understanding local and state housing laws, executing a lease, finding and managing a tenant, and maintaining a rental property. It’s important to understand the laws as they may affect things like future rent increases, changing use over time, evicting tenants, and moving family into the unit. See below for resources on understanding rental laws, tenants’ rights, and more, and our ADU Worksheets for help with your lease terms.

When is my ADU ready for move-in?

As soon as the final inspection is complete, your ADU is ready for move-in! Make sure utility services are set up, an address is established, and other preparations are in place. See below for more responsibilities of being a landlord.

What are my responsibilities during construction?

While your contractor will lead the construction process, you will have the following responsibilities:

  • Keep in touch with your contractor and set up a schedule for checking in.
  • Regularly walk through the construction area to monitor the quality of the work and make sure the work is progressing the way you expect.
  • Be prepared to make decisions about the details—light fixtures, appliances, and other materials—in a timely manner so your contractor can stay on schedule.
  • Follow the contract you agreed to, including any changes as described specifically in a change order form.
  • Although your contractor will usually arrange the required city or utility inspections, it is your responsibility as the property owner to make sure that the inspections are conducted as required.
How can I keep construction costs down?

Construction costs for your ADU will vary significantly depending on personal preferences, site conditions, location, and many other factors.

Size: Despite what many think, smaller ADUs may cost almost the same as larger ones. Many costs like foundation, kitchen and bathroom work only increase slightly for larger ADUs. Kitchen costs will range from $25,000–$50,000 with each bathroom ranging from $15,000–$25,000.

Type: New construction, both detached and attached, tend to be the most expensive. Garage conversions are not much cheaper than new construction if at all. Conversions of interior space (basement or otherwise) are often the cheapest.

Other factors:

  • Quality of interior finish work and amenities
  • Architectural form and details
  • Extent of utility, structural, mechanical, electrical, and plumbing upgrades required
  • Required site upgrades (sidewalks, sewer and water)
  • Whether sprinklers are required
  • Whether doors and windows meet emergency exit standards
  • Lot complexity (slope, trees, fault lines, etc.)
How do I find a contractor?

If you are not using a design/build firm, you will need to find a contractor to take over for the construction phase of your ADU.

JumpstartADU has an ADU Contractor List to help you identify professionals who work on ADU in our area. This list includes building professionals who participated in outreach events and/or requested to be included. It is not vetted and serves as an informational resource only. Be sure to do your research and reference the rest of this section before hiring anyone to work on your ADU.

See more details about the hiring process in the Hire Your Contractor step, below.

Can I renew my building permit if the project is delayed or paused?

Unincorporated El Dorado County: Permits expire two years from date of issue. May be renewed up to twice for another year before/within 30 days of expiration, if permit holder has tried to pursue construction and has completed inspections as needed. The permit holder can apply for permit reactivation after the four-year period if the project hasn’t gotten a final inspection.

Placerville: Permit expires one year from date issued or 180 days from last approved inspection. If construction has begun, an extension may be granted by the Building Official. If no work has commenced, a new permit is required.

Can my ADU be stopped because of other noncompliance issues on my property?

In most cases, state law no longer allows cities and counties to comment on pre-existing zoning issues unrelated to the ADU. For example, you should not receive comments about correcting the main house or a fence unrelated to the ADU, unless there is an obvious public safety issue.

What if I have a building code violation or unpermitted structure on my property? 

State law says an ADU permit cannot be denied due to nonconforming zoning, building code violations or unpermitted structures unless there is a threat to public health or safety, and they are not affected by building the ADU.

What if I have an unpermitted ADU?

An unpermitted ADU can make it difficult to sell or refinance your property. If an unpermitted unit is discovered and is under construction, the county will issue a stop work order. If the building is complete, it will need an as-built permit, which has extra fees and requires substantial physical work on the building to assess the condition and details.

For unpermitted ADUs built before January 1, 2018, state law says a permit to legalize cannot be denied even if there is a violation of ADU laws or building standards, unless it is a “health and safety concern” or if the building is deemed “substandard” by state Health and Safety Code.

What permits are required for ADUs and JADUs?

All ADUs and JADUs require building permits in order to start construction. Other permits are required based on location, special zones, ADU type, and other conditions. See more details below.

Are there pre-approved ADU plans I can use?

El Dorado County is currently working on permit-ready ADU plans that will save you time and money in the design and permitting process. When those plans are ready, this site point you in the right direction.

Are there design standards I need to follow?

Your ADU may be expected to comply with objective design standards, such as roof pitch, landscaping guidelines, and others. For instance, City of Placerville properties in Historic Districts require a review for consistency with historical criteria, and ADUs in architecturally controlled Community Services Districts require architectural approval before building permits are issued. Confirm applicable design guidelines with local staff before beginning the design process.

When do I show my designs to Planning staff?

Once you have a design established with your architect/designer, it’s a great idea to discuss it with Planning staff so they can point out any issues before you prepare your application. See our ADU Worksheets for questions you might want to ask.

How do I find an architect or designer?

Most homeowners choose to work with some type of design professional to plan their ADU and help throughout the process. Bringing on a professional early in the process is often key to getting your ADU approved quickly, managed efficiently, and built cost-effectively. Relevant experience and fit will be critical.

There are a variety of types of designer, and they may be an architect, builder, “designer,” design/build, or a modular/prefab company. If you’re hiring a local individual or team, they’ll likely start the process by visiting your home and talking to you about your ideas and goals. If it seems like a good match, they will prepare a proposal detailing their services and fee. Professionals typically charge for an initial consultation or proposal.

The American Institute of Architects provides helpful information for homeowners and maintains a local Central Valley chapter website where you can find professionals accepting new work.

You can also check out our Contractor List to see if it includes any design professionals who interest you.

See our ADU Worksheets for a list of questions to ask a potential architect or designer.

Can I make rental income?

Rental income is a major benefit of having an ADU or JADU on your property – for many people, it supplements their fixed income and provides an opportunity to grow their savings. Remember, short-term rentals are prohibited.

Make sure to consider potential income when planning the finances for your project.

Can I eventually sell my ADU separately from the main building?


JADUs: You’ll need to record in a deed restriction for the property that the JADU cannot be sold separately from the primary home.

ADUs: El Dorado County does not require a deed restriction for ADUs. Placerville requires a deed restriction stipulating that the ADU can’t be sold separately from the primary residence. See more information here.

How will building an ADU affect my taxes and property value?

Adding an ADU will likely affect your property taxes and the resale value of your home. However, your primary house will not be reassessed, and your property taxes will only increase based on the added value of your ADU. For example, if you build an ADU that adds $150,000 to your property value, and your tax rate is 1%, your taxes will increase by 1% x $150,000, or $1,500 per year.

Building a JADU will have a significantly smaller impact on assessed value. In some cases, your taxes will not increase at all. Home sharing will also not increase the assessed value of your home. Generally, garage conversions will not raise your tax bill as much as new construction, but they will also not add as much value.

Each property will require a one-on-one analysis to determine the added value of an ADU, so contact the El Dorado County Assessor’s Office once you have an idea of your plan. They will be able to provide you with a rough estimate of tax implications.

Adding an ADU may impact your income taxes as well. This can be rather complicated, and it’s best to discuss these with a tax advisor.

What if I don’t have a lot of money available right now to build an ADU?

If you have equity in your home, a cash-out refinance or home equity loan/line of credit (HELOC) might work for you. Financing is typically unavailable for homeowners with lower income and insufficient home equity, but the California Housing Finance Agency (Cal HFA) ADU Program has provided grants of up to $40,000 to qualified homeowners – check their website for the most up-to-date information.

How am I going to pay for an ADU?

Many homeowners use a mix of options to finance their ADU, including savings, funds from family, and/or loans. It is strongly recommended that your financing is in place before construction starts. Be sure to factor in potential rental income since that will help you repay loans. See Casita Coalition’s ADU Finance Guide for Homeowners for more details on financing options and our Worksheets (LINK) for questions to help you decide a financing strategy.

What will it cost to build an ADU?

In general, it is helpful to avoid having a fixed budget total in your head as you explore your options.The cost to build an ADU typically ranges from $30,000 for a simple interior conversion JADU, to $400,000+ for a large detached ADU with high-end finishes on a hillside lot. Cost per square foot is a good way to estimate, though this too can range — a very rough placeholder for you to use is $275 per square foot for construction (“hard costs”) and design and fees (“soft costs”), depending on your design and the materials you chose.

What if I’m in a high-fire severity area?

Wildfires are a reality throughout our region, which is why it is important to understand the risk in your area. If your property is in a Fire Hazard Severity Zone or Fire Protection District there may be additional requirements or reviews. Find out about your location and talk to staff early on to learn how where you live might impact your ADU.

State agencies have developed several resources and guidelines to help. View the Fire Severity Zone Map and plug your address into the Fire Hazard Severity Zone Tool to look up your property and identify your zone. Use the Homeowners Checklist and review the Disaster Ready Guide and Board of Forestry Code to make sure your ADU and property are fire safe.

Do I need to do anything special for a high-altitude ADU?

ADUs on parcels above 4,000 feet elevation must have bear-resistant garbage enclosure(s). Contact Environmental Management for more info.

What if I’m in a high snow or flood area?

Hazard requirements depend on property elevation and location, and may factor into ADU plans. Talk to staff early on to see what additional requirements your team will need to include.

What if my property is in a Community Services District?

Unincorporated El Dorado County: If the property is within the architecturally controlled area of El Dorado Hills Community Services District or Cameron Park Community Services District, architectural approval of the plans from the district prior to permit issuance is a requirement. Failure to obtain approval may delay issuance of your permit.

What if my property is in a historic district?

Unincorporated El Dorado County: Contact local staff to confirm the process and submissions required for ADUs in historic districts.

City of Placerville: Properties in Historic Districts may require Historical District Review for ADU projects and are likely subject to design review for consistency with historic criteria. Confirm exact requirements with Planning staff. See the Historical District Review Application for more information.

Will my ADU need new utility connections?

Conversion ADUs: New connections and fees not required.

Attached/detached ADUs: Separate utility connections and connection fee/capacity charges are required for new ADUs and are due when building permit is issued.

What if I have a septic system and/or well?

Sewer Districts and Onsite Septic Systems: If your property is outside of a sewer service district, you will need to find out if your septic system will meet local requirements when adding an ADU to your property. You may have to increase your septic capacity (add a new tank) or establish a new water source, which can be an unexpected cost, so talk to the El Dorado County Environmental Management Department early in the process to find out (see the Contact page for details).

Water Wells: If your home is not served by the public water system, El Dorado County Environmental Management will require a capacity report to ensure the existing water well is adequate for an additional residence. You must submit a perc test, septic design, and well production report to Environmental Management (with or after building permit application).

City of Placerville: Septic systems are not permitted in Placerville unless the public sewer main is greater than 200 feet from the residence. Septic systems require a permit application and review and approval by El Dorado County Environmental Management Department.

Will I need to add parking?

Parking is much less of a concern than it used to be. See details below for El Dorado County and the City of Placerville.

Unincorporated El Dorado County:
One off-street parking space required per unit, unless:

  • The unit is a JADU
  • Within ½ mile to public transit
  • In a Design Review-Historic Combining Zone (-DH)
  • Converted from primary dwelling or permitted accessory structure
  • On-street parking permits are required but not offered to ADU occupant
  • Within 1 block of car share

The required space may be tandem or in the side yard/setback (ask Planning staff to verify allowed placement). Garage conversions do not require a replacement parking space.

Detached ADUs: One off-street space required, unless:

  • Within ½ mile to public transit
  • In architecturally and historically significant historic district
  • On-street parking permits are required but not offered to ADU occupant
  • Within 1 block of car share

Attached or conversion – no off-street parking requirement

Multi-family: One parking space per unit. Replacement parking required for any parking spaces eliminated by new construction.

The required space may be tandem or in the side yard/setback (ask staff to verify allowed placement).

When a garage, carport, or covered parking space is replaced by an ADU, the parking space does not need to be replaced. JADUs are still subject to parking requirements if created within an attached garage.

Can I rent my ADU as an AirBnB or other short-term rental?

No. ADUs and JADUs cannot be rented short-term.

El Dorado County: Minimum 30 day rental.
Placerville: Minimum 31 day rental.

Do I need to live in the main house to build an ADU or JADU?

Until at least 2025, homeowners are not required to live on their property if it includes an ADU. However, JADU owners need to live in the primary unit or the JADU – and this will need to be recorded in a deed restriction for the property.

I don’t think I can fit an ADU on my property – what can I do?

According to state law, rules about setbacks, lot coverage, and open space requirements cannot restrict you from building an 800 square foot ADU, as long as the ADU has setbacks of at least 4 feet and is not above 16 feet tall. Front setbacks also cannot restrict you from building an 800 square foot ADU, which means an ADU can be in a front yard – but only if rear or side placement isn’t possible.

How large can my ADU be?

According to state law, most ADUs can be at least 800 square feet, as long as rear and side setbacks are at least 4 feet and it is not above 16 feet tall. Otherwise, size limits depend on your property. No room behind or next to your main home? You can build it in your front yard instead.

See more details on the Learn the Rules page.

Can I build an ADU and a JADU?

Homeowners can build both an ADU and JADU on their property. Multifamily properties can have at least two detached ADUs. Talk to Planning staff for more information.

Can I convert my garage into an ADU?

Homeowners can convert legally built structures (garage, barn, art studio) into an ADU. JADUs can be converted from an attached garage, but not detached.

If you demolish your garage or other enclosed structure and build an ADU in its place, the ADU can be in the same footprint if it’s the same size and height of the structure it’s replacing. You may need to provide replacement parking; check with Planning staff for more details (see the Contact page).

Demolition permits for an existing detached garage can be processed at the same time as the ADU permits. Note that garage conversion ADUs may require significant moisture barriers and other design elements in order to meet building codes.

Garage conversions do not require off-street parking spaces, nor do they require replacement parking (with an exception for JADUs in Placerville; see below).

City of Placerville: There must be documentation that the building was legally built, and this may be used as a building permit (subject to review by director). The building must also be upgraded to meet the current code. Conversions must meet a variety of other standards and criteria similar to new construction (confirm with Planning staff). JADUs converted from an attached garage may be required to provide replacement parking.

Am I allowed to build an ADU?

In most cases, yes! ADUs and JADUs are allowed in all single-family and mixed-use zones. If residential buildings are allowed, ADUs are almost always allowed too (with limited exceptions for safety, traffic, and water). Confirm with Planning staff (City of Placerville Planning Department or El Dorado County Planning Services) – see our Contact page for more information.

Do I need to tell my neighbors?

You’re not required to tell your neighbors about your ADU, but it’s always a good idea to communicate with them early in the process. Your project will run more smoothly if they are kept informed, and they may have great ideas for your project!

If you live in a Neighborhood or Homeowners Association, talk with your representative or board early in the process. They can’t prevent you from building or renting an ADU, but they may have guidelines you’ll need to know for design and construction.

How long does it take to build?

Building an ADU is an investment of time as well as money. Most projects take one to two years to complete. Typically, it takes homeowners one to three months to get started and assemble their team, then one to six months to develop plans, meet with the city, and submit the application. Depending on what permits are required, how many rounds of review are required and how quickly a homeowner and their project team can respond to comments, it will take one to six months to get permits. Construction usually takes six to twelve months.

What do I do first?

The best place is to think about what you want, understand your goals and concerns, and look at other ADUs for inspiration. Once you have some ideas in mind, consider your budget and move on to Learn the Rules.

What is the difference between a site-built and a prefabricated or manufactured ADU?

Site-built/Traditional: A traditionally constructed ADU is designed and built specifically to your preferences and property and built on site (“stick-built”). This option allows for a lot of customization and smaller changes to be made throughout the construction process.

Prefabricated/panelized/modular: These ADUs are partially or mostly built in a factory, then shipped to your site to be put together. Sometimes the company will include all services in their fee (“turn-key”), including help with permitting and all on-site construction tasks (e.g., laying the foundation, utility hookups, etc.). Other times you’ll need to hire additional professionals to help.

What is the difference between an ADU and a JADU?

Accessory Dwelling Units (ADUs) come in many shapes and sizes but are always a self-contained home that is usually smaller than the main house and legally part of the same property. They must have a kitchen, bathroom, and place to sleep, and typically range from studios under 500 square feet to large homes with multiple bedrooms.

Junior Accessory Dwelling Units (JADUs) are within the footprint of your home (or attached garage) and less than 500 square feet. They can share a bathroom with the main home and/or have an efficiency kitchen (sink, cooking appliance, fridge, and small counter). Construction costs for JADUs are typically much lower. In most cases, the property owner must live on site in either the main home or the JADU.

State law now allows homeowners to have both a JADU and a regular ADU on their property.


Tell us your thoughts!

Please give us feedback about ADUs in our area. If you leave your contact info, we may be able to get back to you with more information. 

If you’re looking for specific advice or information about your property and ADU, please use the contact information for El Dorado County or the City of Placerville at the bottom of this website. 

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