ADU Builder in Lynwood, CA: Local Rules, Costs and Permits

How big can an ADU be on a Lynwood single-family lot?

The City of Lynwood guide to ADUs and JADUs sets the rules for a lot with an existing or proposed single-family dwelling. A detached ADU can be up to 1,200 square feet. An attached or interior ADU is measured against the interior habitable floor area of the home it attaches to, with 800 square feet as the qualifying size for a statewide exemption ADU, and it cannot exceed 1,200 square feet. Side, street side and rear setbacks are at least 4 feet, and the front setback is the same as the zone front setback, with a statewide exemption ADU allowed to encroach into that front setback to the extent feasible. Height is equal to the zone height limit, which the guide lists as 35 feet for the R-1, R-2, R-3 and PRD zones. The architectural treatment has to match the primary dwelling unit. A detached ADU also keeps a 10 foot wall-to-wall separation from the primary unit, 6 feet from a detached accessory structure on the same lot, and 20 feet from the primary unit if either building is 25 feet or more in height.

How long does an ADU permit take in Lynwood?

The city step-by-step guide says the required submittal goes to the Planning Division through Edgesoft at the same time as the ADU application, and that sending plans at different times extends the processing review time. After the application fee is paid, the city reviews the plans and approves or denies the ADU within 60 days. The Building and Safety Division notifies by email within a 30-day period. Los Angeles County Fire Department submittals are separate from the building plans and go to the Fire Department, and a fire sprinkler plan is usually not required when the existing home has no sprinklers. State law sets the backstop: written notice of completeness within 15 business days, a decision within 60 days, and a complete application the city does not act on in that window is deemed approved.

What fees does the City of Lynwood charge for an ADU?

The city ADU fee sheet lists an impact fee when the unit is over 750 square feet, based on scale, and the ADU guide says impact fees on units of 750 square feet and greater are proportional to the square footage of the existing home. The Art in Public Places in-lieu fee is 1.5 percent of the total project cost over $100,000. Building permit fees run by valuation: $541.00 for a project from $25,001 to $50,000, $892.00 from $50,001 to $100,000, and $1,297.00 from $100,001 to $500,000. Planning charges $562.00 for a single-family site plan review with up to two reviews and $70.00 for a site inspection, and additional plan reviews from the third resubmittal cost $170.00 per hour. All fees are paid through Edgesoft.

How much does an ADU cost in Lynwood?

L Square publishes configured prefab prices on its cost page: Model 600 at $180,000, Model 800A and Model 800B at $240,000 each, Model 1000A and Model 1000B at $295,000 each, and Model 1200 at $354,000. Those are unit prices, not a quote for your lot. Site preparation, utility connections, structural engineering, permits and finish selections are quoted separately for each property, and city fees land on top of that list. A 600 square foot unit is a 2 bed, 1 bath layout, the 800 square foot models are 2 bed and 2 bath, and the 1,000 and 1,200 square foot units are 3 bed and 2 bath.

Does Lynwood have pre-approved ADU plans I can build from?

The city owns the pre-approved standard ADU plans and property owners can use them free of charge. The program offers two 1 bedroom and 1 bath models and one 2 bedroom and 1 bath model, each with a choice of roof lines, exterior finishes and an interior layout that can include accessible features such as wider doorways and hallways. The detached plan on a single-family lot is 1,200 square feet for a 3-bedroom, one bath, single story unit, with 4 foot side and rear setbacks, a 10 foot front setback and a 10 foot street side setback at a corner. The attached plan is 850 square feet for a unit with up to one bedroom and 1,000 square feet for a unit with two or more bedrooms. You submit the building permit online through Edgesoft, attach a detailed plot plan, sign the hold harmless agreement, and name the plan in the permit application description.

What should I check before building an ADU in Lynwood?

Check the zoning first. The city says an ADU can be built on property zoned for single-family residential, the applicant has to be the property owner or be authorized by the owner, and the property needs an existing or proposed dwelling. The pre-approved plans are city owned and free, and using one still means city staff check site conditions against the zoning code and foundation requirements. Structural plans have to be prepared by a California state licensed architect or engineer, general plans can be prepared by an owner or contractor, and the permit goes to a California state licensed contractor or to the property owner. ADUs and JADUs have to meet the prescriptive requirements for conventional light-frame construction in the California Residential Code. Grading plans are generally required at 50 cubic yards of combined cut and fill, a landscape documentation package is required at 2,500 square feet of landscaping installed by a developer or 5,000 square feet installed by a homeowner, and a CalHFA grant can cover up to $40,000 in pre-development and non-recurring closing costs. You have to pull the permit within 1 year of the application date.

Official Lynwood ADU sources

• The city guide to ADUs and JADUs sets the single-family lot rules: a detached ADU of 1,200 square feet maximum, side, street side and rear setbacks of at least 4 feet, the applicable zone front setback, height equal to the zone height limit, no required parking, no owner occupancy requirement, a minimum rental term of 30 days, impact fees on units of 750 square feet and greater, and the 1.5 percent Art in Public Places in-lieu fee above $100,000 of building valuation. Official source
• The city pre-approved standard ADU plans are owned by the City of Lynwood and may be used by property owners free of charge. The program offers two 1 bedroom and 1 bath models and one 2 bedroom and 1 bath model. On a single-family lot the detached plan is 1,200 square feet for a 3-bedroom, one bath, single story unit with 4 foot side and rear setbacks and a 10 foot front setback. Official source
• The city step-by-step guide says the required submittal goes to the Planning Division through Edgesoft at the same time as the ADU application, that the city approves or denies the ADU within 60 days after the application fee is paid, that the Building and Safety Division notifies by email within a 30-day period, and that the applicant pulls the permit within 1 year of the application date. Official source
• The city ADU fee sheet lists an impact fee when the unit is over 750 square feet, an Art in Public Places in-lieu fee of 1.5 percent of the total project cost over $100,000, construction permit fees of $541.00 for $25,001 to $50,000, $892.00 for $50,001 to $100,000 and $1,297.00 for $100,001 to $500,000, a single-family site plan review at $562.00 for up to two reviews, a site inspection at $70.00, and additional plan reviews from the third resubmittal at $170.00 per hour. Official source
• The city ADU page states that an ADU can be built on property zoned for single-family residential, that the applicant must be the property owner or be authorized by the property owner, that the property must have an existing or proposed dwelling, and that the types are a junior ADU inside the walls of the home, a detached ADU, and a conversion or attached ADU. Official source
• The city ADU design page states that a California state licensed architect or California state licensed engineer prepares the structural plans, that general plans may be prepared by an owner or contractor, that the city pre-approved standard ADU models were approved by the Building and Safety Division for compliance with the Building, Residential and Green Codes, that ADUs and JADUs must meet the prescriptive requirements for conventional light-frame construction in the California Residential Code, and that permits are issued to a California state licensed contractor or to the property owner. Official source
• California Government Code Section 66317 requires a permitting agency to give written notice of whether an accessory dwelling unit application is complete no later than 15 business days after receiving it, to approve or deny a completed application within 60 days, to treat a completed application it has not acted on in that time as approved, to toll the 60-day period when the applicant requests a delay, and to consider and approve an application ministerially without discretionary review or a hearing. Official source
• California Government Code Section 66314 provides that the total floor area for a detached accessory dwelling unit shall not exceed 1,200 square feet, that the total floor area for an attached accessory dwelling unit shall not exceed 50 percent of the existing primary dwelling, that parking requirements shall not exceed one parking space per accessory dwelling unit or per bedroom, whichever is less, and that the local agency shall not require replacement parking when a garage, carport or covered parking structure is demolished or converted to an accessory dwelling unit. Official source
• California Government Code Section 66311.5 provides that a local agency, special district or water corporation shall not impose any impact fee on the development of an accessory dwelling unit that has 750 square feet of interior livable space or less, or a junior accessory dwelling unit with 500 square feet of interior livable space or less, and that impact fees charged for a larger accessory dwelling unit shall be charged proportionately in relation to the square footage of the primary dwelling unit. Official source