ADU Construction
ADU construction: site, permits, and realistic sequencing
Educational guidance for Southern California homeowners. Coastline DC Inc. · California Contractor License #813394 · Established 2002.
Feasibility before floor plans
Setbacks, lot coverage, parking rules, height limits, and utility capacity decide what is possible. A short feasibility review with a licensed contractor saves redraws.
Detached, attached, or conversion
Each path has different structural and fire-separation requirements. Garage conversions and junior ADUs have their own constraints — do not assume a brochure plan fits your lot.
Utilities and access
Sewer laterals, electrical service upgrades, and construction access for hillside or narrow lots often drive cost more than square footage alone.
Permitting as a tracked workstream
California ADU rules are favorable in many jurisdictions, but plan check and inspections still take time. Coastline DC (CSLB #813394) coordinates submittals and inspection milestones as part of the project plan.
Finish the envelope before the interiors
Weatherproofing, openings, and insulation come before cabinetry and flooring. Rushing interiors on an incomplete envelope creates warranty problems.
Practical tips
Common questions
Sometimes — after site constraints are verified. Stock plans still need site adaptation and jurisdiction compliance.
Your licensed general contractor should identify requirements and manage the permit process for the agreed scope.
Often planned together so site logistics and finishes stay coordinated. Discuss sequencing early.
Related
Services and next reading
Next step
Discuss your project with Coastline
No fabricated averages — a project manager reviews your site and goals. Email coastlinedc@gmail.com or start a consultation.
Contact Coastline