Feasibility & Zoning
Lot study, setback verification, FAR calculations, utility capacity, and a clear go / no-go before you commit to design.
Custom ADUs & Conversions
Custom ADU builder in San Diego.
Detached ADUs, junior ADUs, and garage conversions across San Diego, La Jolla, Pacific Beach, Del Mar, Encinitas, Poway, and Rancho Bernardo. Engineered for permit. Designed for resale. Finished for living.
San Diego ADU construction, end to end.
San Diego is one of the most ADU-friendly markets in California. The City's bonus density program, the County's Section 8.5 ordinance, and SB 9 / SB 10 have unlocked secondary dwellings on lots that couldn't have supported them five years ago. We work inside that framework every day — translating it into real square footage, real rental income, and real long-term equity for homeowners across San Diego, La Jolla, Pacific Beach, Del Mar, Encinitas, Poway, and Rancho Bernardo.
Every Lieon ADU starts with a feasibility walk: lot size, setbacks, zoning overlay, utility laterals, fire access. From there we move into design — floor plans, elevations, material palette, and a fixed-fee construction proposal you can hold in your hands before a permit is ever pulled. Once the City stamps drawings, we publish a build schedule and you get weekly walk-throughs until certificate of occupancy.
Detached ADUs
Free-standing secondary dwellings, typically 600–1,200 square feet, with their own entrance, kitchen, bath, and address. Detached units carry the strongest rental and resale premium in San Diego County — particularly in La Jolla, Del Mar, and Encinitas, where short-term and long-term rental demand stays consistently above the metro average.
Junior ADUs (JADUs)
Up to 500 square feet carved out of the existing footprint of a primary residence, with an efficiency kitchen and either a private or shared bath. JADUs are the fastest path to a permitted second unit in San Diego — often eligible for streamlined ministerial review and lower impact fees than a full detached ADU.
Garage Conversions
Single- and two-car garages converted into legal living units. We handle the structural upgrades, the electrical and plumbing rough-ins, the egress, the insulation, and the title-24 compliance — and we leave you with a finished interior that reads like part of the main house, not a converted utility space.
Attached ADUs & Additions
New construction tied into the existing structure — ideal for narrower lots in Pacific Beach, Mission Hills, and the older grids of central San Diego where a fully detached unit isn't feasible without losing yard.
What's Included
From feasibility to certificate of occupancy.
Design & Drawings
Architectural floor plans, elevations, structural, MEP, title-24, and a finish schedule signed off in advance.
Permits & Plan Check
San Diego DSD, County PDS, or local jurisdiction plan check submission and revisions — managed by our team, not yours.
Site & Foundation
Demo, grading, post-tension or stem-wall foundations engineered for San Diego's expansive soils and seismic zones.
Framing, MEP, Finish
One in-house crew through framing, electrical, plumbing, HVAC, drywall, millwork, tile, flooring, and final paint.
Final Inspection & CO
Punch list, final inspections, certificate of occupancy, warranty package, and a professional photo set on completion.
Service Area
ADU construction across San Diego County.
Lieon Housing builds custom ADUs and garage conversions throughout the City of San Diego and the surrounding coastal and inland communities. Every jurisdiction has its own plan-check personality — we know which one you're in.
San Diego
City of San Diego ADU construction across Mission Hills, North Park, Hillcrest, Point Loma, and the urban core. Familiar with DSD's bonus density program and the affordable-set-aside pathway for additional unit count.
La Jolla
Coastal Permit Overlay, La Jolla Community Plan, and view-corridor compliance. Detached ADUs and garage conversions on the steep lots above Bird Rock, Muirlands, and Soledad.
Pacific Beach
High-rental-yield ADUs on the typical PB grid lot. Coastal zoning, alley access conversions, and rooftop deck integrations where the height envelope allows.
Del Mar
Premium detached ADUs and accessory pool houses. Del Mar's Hillside Overlay and lot-coverage limits demand a careful design hand — exactly what we deliver.
Encinitas
From Cardiff to Olivenhain, ADU construction tuned to Encinitas' specific plan-check process and HCD-aligned ADU ordinance. Granny flats, garage conversions, and detached studios.
Poway
Larger-lot ADUs and detached guest houses across Poway and the Old Coach corridor, including septic and well coordination where needed.
Rancho Bernardo
Master-planned community ADUs, including HOA design-review packages for Westwood, Bernardo Heights, and the Greens.
Mission Hills
Mission Hills ADUs and JADUs — small-lot detached units, garage conversions, and historic-overlay-friendly designs that respect period architecture.
Escondido
Escondido detached and junior ADUs — larger inland lots permit more flexible footprints, second-unit rentals, and full-service casitas.
Bonita
Bonita ADUs and South Bay garage conversions — detached cottages, JADUs, and family-suite builds for multi-generational households.
Fallbrook
Fallbrook guest casitas and detached ADUs — acreage gives flexibility for full-size detached units with private access and septic coordination.
Why Lieon Housing
Why San Diego homeowners choose Lieon Housing for custom ADU construction.
As ADU regulations across San Diego County have liberalized, custom ADU construction has become one of the strongest residential investments a homeowner can make. Lieon Housing builds detached ADUs, junior ADUs (JADUs), and garage conversions across San Diego, La Jolla, Del Mar, Mission Hills, and the inland communities of Escondido, Bonita, and Fallbrook — each engineered to current code, designed to add resale value, and finished to the same standard as our whole-home remodels.
Every ADU we build starts with a feasibility review of your specific lot — setbacks, utilities, height limits, and the local plan-check process. Our team handles CSLB filings, City of San Diego or San Diego County permitting, structural engineering coordination, and HOA design review where applicable. Whether you’re adding a 600-square-foot junior ADU in Mission Hills, a fully detached 1,200-square-foot rental cottage in Fallbrook, or a garage conversion in Bonita, the path from sketch to certificate of occupancy is sequenced and accountable.
What separates a Lieon Housing ADU from a stock plan-set: the same Santa Barbara-finish stucco, walnut accents, and matte-black architectural details that define our luxury home remodels in La Jolla, Del Mar, and Escondido. Your San Diego ADU shouldn’t read as a tacked-on building — it should read as a second home, designed and built to the same level of care as the primary residence.
Frequently Asked
ADU questions San Diego homeowners ask us.
How much does an ADU cost to build in San Diego?
A finished detached ADU in San Diego County typically lands between $325 and $525 per square foot, with garage conversions running lower and ground-up units on hillside lots running higher. Lieon Housing publishes a fixed-fee proposal during design — no allowances, no “TBD” line items.
How long does a permit take in San Diego?
Most ADU plan checks in the City of San Diego close within 8–14 weeks. Encinitas, Del Mar, and Poway can run shorter or longer depending on the queue. Junior ADUs and pre-approved standard plans often clear in under 30 days.
Will an ADU pencil as a rental?
In La Jolla, Pacific Beach, and Encinitas, well-designed detached ADUs frequently rent for $3,200–$4,800 per month long-term, and 2–3x that as short-term rentals where allowed. We model the rent and equity scenarios with you during the feasibility walk.
Do you handle the permit process?
Yes. Lieon Housing manages plan-check submission, corrections, and inspector coordination from end to end. You sign drawings; we handle the city.
Can I build an ADU in a coastal zone?
Yes — La Jolla, Del Mar, Encinitas, and parts of Pacific Beach all sit inside the Coastal Overlay. The path is well-defined; we've done it. Expect an additional Coastal Development Permit step on top of standard plan check.