Planning to build an Accessory Dwelling Unit (ADU) in Los Angeles County? Use our ADU Cost Calculator Los Angeles to quickly determine whether your property qualifies for an ADU and to estimate construction, permit, and impact fees.
How It Works:
Enter property size, project type, and estimated construction cost.
Choose whether you are building a new ADU or converting an existing structure.
Get instant estimates of total fees, including building permits, plan check, inspections, and impact fees.
ADU Feasibility & Cost Calculator – Los Angeles County
This calculator helps determine whether your property qualifies for an Accessory Dwelling Unit (ADU) and estimates associated costs, including construction value, permit and impact fees. Use as an initial budgeting guide — JDJ Consulting can provide exact figures.
*These figures are estimates only. Actual fees depend on zoning, lot size, utility connections, fire code, state law exemptions (e.g., ADU under 750 sq ft may be exempt from certain impact fees)
Key Terms:
Permit Fees: Costs charged by the city or county to issue and inspect your ADU permit.
Plan Check Fee: City review of your ADU plans for compliance with building codes.
Impact Fees: Fees for schools, parks, and infrastructure that may apply to new units.
Feasibility: Determines whether zoning and property size allow for an ADU.
Estimated ADU Fees – Los Angeles County (2025)
This table provides general estimates of ADU construction, permit, and impact fees by ADU type. Actual costs depend on property specifics, zoning, and city/county regulations. Use as an initial budgeting guide.
| Fee Component | Description | New ADU | Conversion / Garage ADU | Junior ADU (JADU) |
|---|---|---|---|---|
| Base Construction Permit Fee | Percentage of construction value; minimum fee applies. | $1,800 – $18,000+ | $1,500 – $15,000+ | $1,000 – $10,000+ |
| Plan Check Fee | City review of ADU plans; typically 60–70% of base fee. | $1,260 – $12,600+ | $975 – $9,750+ | $600 – $6,000+ |
| Inspection Fees | Covers required inspections; adjusted for ADU area. | $300 – $600+ | $200 – $500+ | $150 – $400+ |
| Impact & School Fees | Fees for schools, parks, and infrastructure; may be waived for ADUs under 750 sq ft. | $9,000+ | $6,000+ | $4,000+ |
| Total Estimated Fees | Sum of all components; actual costs may vary per property. | $12,360 – $40,200+ | $9,675 – $35,250+ | $5,750 – $20,400+ |
*Disclaimer: Estimates only. Actual fees vary based on zoning, lot coverage, setbacks, utility connections, and local regulations. Consult JDJ Consulting or LADBS for exact fees.*
Expert Help:
After estimating, JDJ Consulting can review your project, confirm fee accuracy, and expedite approvals. Book a Consultation or call (818) 793-5058 to speak with an expert.
