Frequently Asked Questions

If you can’t find the answers to your questions here, just give us a call and we’ll be happy to help you realize the ADU of your dreams.

Accessory Dwelling Units (ADUs) are known by many names: granny flats, in-law suites, backyard cottages, secondary units, to name a few. Whatever you choose to call them, ADUs are proving to be an innovative, affordable, effective option for single family and multi-family property owners to add value to their property and passive income through rental opportunities.

The three main types of ADUs are: Attached, Detached, or Conversion units.

  • An Attached ADU converts space within the primary structure, such as an attic, garage, or basement.
  • A Detached ADU is a separate stand alone structure from the primary residence, in the backyard or the side yard.
  • A Conversion ADU is created from converting existing non-livable space (such as attics, storage, garages, or basements) into a separate unit.

Whether an attached, detached, or conversion ADU, each unit must have a separate entrance, kitchen, bathroom and sleeping facilities.

  • Maximum Unit Size: Max of 1,200 sq. ft. or 50% of the primary structure. ALL cities are required to approve any attached or detached ADU under 1200 square feet unless the city adopts a new ADU ordinance setting local government standards for a single-family zoned lot. If a city adopts such an ordinance it must follow two restrictions: One, no maximum unit size limit under 800 square feet (or 1000 square feet for a two-bedroom ADU). Two, a floor area ratio must allow development of at least one 800 square feet attached or detached ADU on every lot.
  • Minimum Unit Size: Must have a minimum living area of 150 square feet.
  • Kitchen: Must have an efficiency kitchen including: sink, cooking appliance, counter surface, and storage cabinets.
  • Bathroom: Must include the minimum of a 3/4 bath.
  • Separate Entrance: In most cases, must have its own separate entrance.
  • Parking: There are no parking requirements for an ADU erected through the conversion of existing space, or located within a half-mile walking distance from a bus stop or transit station. Parking spaces for an ADU may be street parking, tandem driveway parking and may not exceed one space per unit or bedroom.
  • Fire Sprinklers: ADUs are to be considered part of the primary residence for the purposes of fire and life protection ordinances and regulations, such as sprinklers and smoke alarms. Therefore, ADUs are not required to have fire sprinklers if they are not a requirement for the primary residence.
  • Ministerial Approval Process: Cities are required to approve an ADU within 60 days, without a hearing or discretionary review.
  • Limit: There’s a limit to two ADU’s (one junior and one detached or attached) per residential lot zoned for single-family residences.
  • Owner Occupancy: Cities cannot require owner occupancy until 2025.
  • Prohibition on Sale of ADU: Cannot be sold separately from the primary residence.
  • Conversion of Existing Structure: A conversion ADU can be created from a legal structure built at any time (i.e. garage, accessory structure, storage room) and has setbacks sufficient for fire safety based on local ordinance.
  • Conversion Size: There is no limit to the size of conversion for pre-existing structures.
  • Conversion Additional Square Footage: May be expanded up to 150 sq. ft., not to exceed 1200 sq. ft. total, except as may be necessary to accommodate ingress and egress to the ADU.
  • New Home & ADU Construction: An ADU can be built at the same time as a primary unit, under most of the same rules.
  • Single Story Height Limit & Property Line Set Backs: The height limit for a single story ADU is 16ft, with a side and rear set back of 4ft.
  • Second Story Height Limit & Set Backs: The height limit and set back requirements for a two story ADU is dependent on local ordinance.
  • Lot Requirements & Coverage: There are no minimum lot size requirements.
  • Development & Impact Fees: ADUs 750 square feet or smaller are not subject to impact fees (schools, parks, water). Fees for ADUs over 750 square feet are limited and determined based on the primary residences square footage.
  • Homeowners Associations: An HOA must allow the construction of ADUs.
  • Utility Fee Requirements for Conversions: New or separate utility connections and fees (connection and capacity) are not required, where an ADU is being built within an existing structure (primary or accessory).
  • Persons with Disabilities: Local governments must provide exception to zoning and land use regulations which includes an ADU ordinance for people with disabilities. Potential exceptions are not limited and may include development standards such as setbacks and parking requirements and permitted uses that further the housing opportunities of individuals with disabilities.
  • Sale of an ADU: Cannot be sold separately from the primary residence.
  • Short Term Rentals: An ADU or JADU can only be rented for terms longer than 30 days. Vacation rentals are not permitted.

Junior Accessory Dwelling Units (JADUs) are exactly as the name implies, a smaller version of a Single Family ADU with a few noted restrictions. It must be erected within a proposed or existing single family dwelling. Most often, they share utility service and mechanical appliances with the main unit. These units are the most common ADU homes. JADUs present no additional stress on utility services or infrastructure because they simply repurpose existing space within the residence and do not expand the dwellings planned occupancy.

One of the most significant ADU rule changes for 2020, is a provision that allows both an ADU and a Junior ADU (JADU) on the same lot with a proposed or existing single-family dwelling. Now you can add two rental units to your property: an ADU and a JADU. This law applies not just to Los Angeles, but statewide, throughout California.

  • Maximum Unit Size: No more than 500 sq. ft., and a limit of one JADU per lot zoned for single-family residences. It must be constructed by converting existing non-livable space within the existing structure (i.e. basement, storage, attached garage, car-port, patio, etc)..
  • Kitchen: Must meet “Efficiency Kitchen” requirements: sink (16”x16” max.) with a small drain line (1.5” diameter max.); a food preparation counter and storage cabinets that are of reasonable size in relation to the size of the JADU, and appliances that do not require natural or propane gas.
  • Bathroom: Interior access to a bathroom.
  • Separate Entrance: Exterior entrance is separate from the primary residence.
  • Parking: Parking is not required.
  • JADU Additional Square Footage: May include an expansion of up to 150 sq. ft. beyond the footprint of the existing accessory structure, but this expansion is limited to accommodating ingress and egress.
  • Owner Occupancy: Owner occupancy of one of the units on-site is required. Owner-occupancy is not required if the owner is another governmental agency, land trust, or housing organization.
  • Ministerial Approval Process: Cities are required to approve an ADU within 60 days, without a hearing or discretionary review.
  • Prohibition on Sale of JADU: Prohibition on the sale of the JADU separate from the sale of the single-family residence.
  • Short Term Rentals: If a JADU is rented, the unit shall not be rented for a period of less than 30 consecutive calendar days;
  • Up to 2 new detached ADUs is allowed; either new construction or by converting detached existing non-livable space (i.e. storage, detached garage).
  • Up to 25% of the total existing unit count can be added as attached ADUs by converting existing non-livable space within the existing structure (i.e. basement, storage, attached garage, tuck-under parking).

The principal reason most property owners decide to build an ADU is to increase the value of their property and/or generate passive income through the rental market. ADUs can also serve as independent living space for family members or loved ones. They create the possibility for multigenerational households which makes it easier and less expensive to care for aging parents. Moreover, ADUs cost less than other forms of housing and make efficient, environmentally friendly, use of existing land. Finally, downsizing and minimalist living is a trend that continues to grow. ADUs allow people to simplify their lives and still live in a neighborhood setting.

ADUs are particularly attractive in markets like Greater Los Angeles where available housing is in short supply, and they can also help create more affordable housing that can help mitigate the ongoing housing crisis in Southern California.

Prefabricated means that our revolutionary Light Gauge Steel (LGS) prefabricated, modular ADUs are built off site in a state-of-the-art factory by skilled tradesman on a production line (just like the majority of items we use on a daily basis).

In our exhaustive search to find the most innovative construction methodology, we found prefabricated construction to be a more efficient, faster and sustainable way to build, and allows for efficiencies in the overall process that realizes significant cost and time savings over traditional site construction methods.

  • Building indoors on a production line is faster, increases quality, lowers costs and eliminates the chance of wet homes/mold.
  • Time savings are achieved because State of California Approved plans are submitted to the Local Jurisdiction for a building permit, and we can complete site work (grading and utility and foundation prep) at SAME time the ADU is prefabricated in the factory.

Even with today’s challenges, our typical time frame to complete a prefabricated ADU project is 6 to 9 months from permit submission to project completion with minimal project site disruption.

Yes, if the garage is a legal structure. Although, it must meet current building and fire codes since it will be considered a change in use.

Yes, converting your basement to an ADU or a Junior ADU is allowed. However, you must meet the building code, which includes adequate ceiling heights and minimum sizes on windows for ingress and egress.

es, we can typically match the colors and style of most homes. We also have many options available that can increase the “curb appeal” of your ADU including: dormers, porches, bay windows, board/batt, stucco, tile roofing, and solar.

ADU Concepts is a Full Service General Contractor, Authorized Dealer & Certified Installer of Lytemods Dwellings with combined experience of the company principals and key employees of over 50 years building with traditional and prefabricated construction. ADU Concepts provides all services necessary to complete your project from design, to permitting, to fabrication, to site work and installation of your Accessory Dwelling Unit. We offer a complete turn-key ADU construction project.

Cities that we currently work with in Southern California: Long Beach, Santa Ana, Seal Beach, Signal Hill, San Pedro, Rolling Hills Estates, Rancho Palos Verdes, Lomita, Torrance, Redondo Beach, Hawthorne, Compton, Lakewood, Norwalk, Cerritos, Los Alamitos, Cypress, Buena Park, Downey, Whittier, Los Angeles, Culver City, Santa Monica, Manhattan Beach, El Segundo, Montebello, Hacienda Heights, Fullerton, Anaheim, Garden Grove, Westminster, Fountain Valley, Yorba Linda, Placentia, Villa Park, Tustin, Orange, Irvine, Lake Forest, Laguna Beach, Huntington Beach, Costa Mesa, Newport Beach, Laguna Niguel, San Juan Capistrano, Mission Viejo, San Clemente, Rancho Santa Margarita, Alhambra, Arcadia, Pasadena, Glendale, Burbank, Encino, Calabasas.

Even though many property owners are able to do their own zoning research, getting an expert opinion will give you another level of confidence about your project. We are experts in city zoning and planning office communications, so we can help you alleviate confusion and frustration, and make sure you’ve covered all your bases. This includes checking overlapping and underlying zoning requirements of your city.

Our Free ADU Evaluation Report provides you the easiest way to take the first step on your ADU project without commitments.

Find out if your home qualifies and get a free ADU Evaluation.

It depends on your financing option, and the amount of rent that can be collected in your area. In most situations you can refinance your home and include the new ADU at a much better rate.

Depending on the financing option you choose, as a rental property owner, you can likely deduct a portion of their mortgage interest, insurance, property taxes, depreciation and utilities. Please consult your tax advisor for specific guidance.

Yes, but not by very much. When you build an ADU, your city will conduct a blended assessment, which does not affect the value of your existing property, but instead assesses the cost of the construction and adds that to your original property value. Your taxes will only increase by 1.1% of the total cost of the improvements. In most cases, this equals only a couple hundred dollars extra per year — a small price to pay compared to the rental income your ADU will make.

You should notify your insurance company if you decide to rent your ADU. They may increase your annual premium by $20-$35 to cover the liability if your ADU is constructed out of lumber. One of the benefits of working with us is that we use LGS in all of our new construction projects, which could potentially save you up to 50% in your insurance premium.

The California Health and Safety Code (HSC), Section 65583(c)(7), requires that cities and counties develop a plan that incentivizes and promotes the creation of ADUs that can be offered at affordable rent for very-low to moderate-income households.

As recapped below, HCD has developed a list of existing state grants and financial incentives in connection with the expenses for the planning, construction and operation of an ADU with affordable rent for very low to moderate- income households.

Potential State Grants and Financial Incentives for ADUs

  • CalHome ProgramState funds to local public agencies and nonprofit corporations for first-time homebuyer mortgage assistance including a home purchase with an ADU or JADU; owner-occupied rehabilitation assistance including rehabilitation of ADUs or JADUs; ADU/JADU assistance including construction, repair, and reconstruction; and homeownership development project loans including predevelopment and carrying costs during construction related to ADUs and JADUs (HCD CalHome program)
  • Local Early Action Planning (LEAP) GrantsState grants to local jurisdictions including eligible partnerships for housing planning, and developing or improving an ADU ordinance in compliance with Section 65852.2 of the Government Code (HCD LEAP program)
  • Local Housing Trust Fund (LHTF) ProgramMatching funds to local and regional housing trust funds. Funds may also be used for the construction, conversion, repair, reconstruction or rehabilitation of ADUs or JADUs (HCD LHTF program)
  • Regional Early Action Planning (REAP) GrantsGrants to council of governments (COGs) and other regional entities for activities relating to housing planning and activities including establishing Prohousing Policies such as adopting ADU ordinances or other mechanisms that reduce barriers for property owners to create ADUs (HCD REAP program)
  • SB 2 Planning GrantsGrants to local governments including eligible partnerships for housing planning and to encourage ADUs and other innovative building types through ordinances, outreach, fee waivers, pre-approved plans, website zoning clearance assistance, and other homeowner tools or finance tools (HCD SB2 program)
  • Community Development Block Grant Program (CDBG)Federal funds allocated to non-entitlement jurisdictions, and non-entitlement jurisdictions that partner with non-federally recognized Native American communities for community development activities including single- and multi-family rehabilitation and potential local ADU rehabilitation and planning programs. Applicants must be income qualified in low- to moderate-income households for rehabilitation and areas for planning. Contact your local jurisdictions for more information.
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