Reliable SD ADUs designs, permits and builds accessory dwelling units across San Diego County. With 25+ years of hands-on concrete, foundation and grading experience, we take your ADU from feasibility to final inspection, and we handle the city so you don't have to.
Answer a few quick questions and we'll review your lot's zoning, ADU potential and likely cost range before we pick up the phone. Prefer to talk now? Call 619-933-5133.
Most ADU projects stall in the gap between the designer, the permit expediter and the builder. We close that gap. Reliable SD ADUs is a single point of responsibility for your entire San Diego ADU project, from the first zoning check to your certificate of occupancy.
Zoning analysis, lot coverage, setbacks, height limits, utility and sewer review, and a realistic budget before you spend a dollar on design.
We prepare, submit and shepherd your plans through the City of San Diego and San Diego County, handling corrections, resubmittals and inspections.
Grading, foundations, framing, utilities, finishes. Our crews specialize in concrete and sitework, the part of an ADU where most budgets go wrong.
San Diego lots are rarely flat and rarely simple. Hillsides, expansive soils, old fills and tight backyard access are where ADU budgets blow up. Our background is exactly there: over 25 years of concrete, foundation and grading work across San Diego County. We engineer and build the part of your ADU that everything else stands on.
Standalone backyard homes, the most popular detached ADU option in San Diego for rental income and family housing.
Additions connected to your existing home, often the most cost-effective way to add a full second unit.
Convert an existing garage into a legal living unit. Often the fastest, lowest-cost path to a San Diego ADU.
Units up to 500 sq ft created within your existing home, with an efficiency kitchen and separate entrance.
Multiple units on one lot under California law and San Diego's ADU Home Density Bonus Program.
SB9 lot split opportunities, rental income ADUs, guest houses and backyard homes, evaluated for your specific parcel.
Honest numbers up front. These are typical 2026 all-in ranges for San Diego ADU projects, including design, permits and construction. Your lot's slope, soil, utility distances and finish level drive where you land in the range.
| ADU Type | Typical 2026 Cost |
|---|---|
| Garage Conversion | $90k – $200k |
| Junior ADU (JADU) | $75k – $175k |
| Attached ADU | $150k – $350k |
| Detached ADU | $200k – $500k+ |
| Multi-ADU Development | Varies by site |
Ranges reflect typical San Diego projects and are not a quote. A free feasibility review gives you a number specific to your property.
We can help connect you with lenders, ADU financing specialists and construction loan providers familiar with San Diego development projects, including HELOCs, construction loans and DSCR investment loans.
Explore ADU Financing OptionsMost San Diego homeowners don't pay cash for an ADU. These are the financing paths our clients use most, explained in plain English on our dedicated San Diego ADU financing guide:
Financing options vary by borrower, property and project scope. We can connect you with lenders familiar with San Diego ADU and infill development projects. Reliable SD ADUs is a contractor, not a lender; loan terms are set by your lender.
This is where ADU projects live or die, and it's the part we handle completely. California ADU law guarantees most single-family lots the right to add an ADU plus a Junior ADU. On top of state law, the City of San Diego's ADU Home Density Bonus Program can allow additional units on qualifying lots when affordability requirements are met, which is how some San Diego properties legally hold multiple ADUs.
We navigate the full regulatory picture for every project:
Building in the unincorporated county? Start with the official San Diego County ADU zoning ordinance page, then call us and we'll translate it into a plan for your parcel. City of San Diego projects follow the City's ADU regulations, which we track as they change.
A realistic San Diego ADU timeline runs 8 to 18 months from first call to move-in. Here's where that time goes, and where an experienced builder saves you months:
We confirm what your lot allows, flag zoning issues early and give you a real budget range. Free, no obligation.
Plans drawn for your lot, your budget and the city's requirements, designed to minimize correction cycles.
Submittal, plan check, corrections and approval. Clean, complete first submittals are how we keep this on the short end.
Grading, foundation, build-out and final inspections, run by crews that have poured San Diego concrete for 25+ years.
We build ADUs throughout the City of San Diego and across the county, including:
One form or one phone call gets you a straight answer: what your lot allows, what it will cost and how long it will take. No pressure, no obligation, just 25 years of San Diego building experience.