Fast, Reliable Garage Conversion ADU Across San Fernando
A garage conversion ADU in San Fernando typically runs $95,000-$165,000 all-in, from measured drawings through final inspection, depending on whether the structure is attached, detached, or a carport. Most San Fernando homeowners receive a written quote within 48 hours of our site visit. Call (661) 528-5298 to schedule yours.
We’re familiar with San Fernando’s specific permit landscape. This 2.4-square-mile city sits completely inside Los Angeles but operates its own Building & Safety Division with its own ADU ordinance, entirely separate from LADBS. That distinction matters. Out-of-town contractors routinely submit to the wrong authority and lose weeks. Our Garage Conversion ADU team has navigated San Fernando’s plan-check process since the city’s ADU rules took shape, and we coordinate dispatch and scheduling from our Los Angeles office with crews serving San Fernando locally.
Why Ellery ADU Studio Lancaster Is San Fernando’s Preferred Garage Conversion ADU Company
We’ve designed, permitted, and built more than 900 ADUs since 2015, the year California’s ADU laws began their major shift. Every one of those projects started with a written price before any work began, per Haven Standard Clause 1. San Fernando homeowners receive the same documentation: a permit set treated as the core product, not an afterthought, and a 365-Day Done Right Promise backed in writing before the first wall opens.
Our San Fernando clients specifically mention the photo record we deliver on every visit. They receive evidence of what we found and what we did, not a summary of how it felt. When we opened a detached garage off Maclay Avenue and found a mudsill shifted off its stem wall with rusted anchor bolts, the homeowner saw the photos, read the engineer’s report, and approved the foundation repair in writing before we touched it. No voicemail queues, either. A live person answers calls 24/7.
We also offer a Free Second Opinion on any written estimate already in hand. If another contractor handed you a San Fernando garage conversion quote, we’ll review it against what we find on site and tell you where the numbers land.
Our Garage Conversion ADU Services in San Fernando

Detached Garage Conversion
Detached garage conversions are the most common ADU project we handle in San Fernando, and for clear reason. The city’s housing stock is dominated by post-WWII single-family bungalows built in the 1940s-1960s, most with detached alley-accessed garages that sit on small lots where a new detached ADU often won’t fit. These structures typically run $110,000-$165,000 all-in. The price includes addressing what we almost always find: sub-100-amp electrical service, galvanized or cast-iron drain lines, and stucco-over-wood framing that needs substantial upgrading. San Fernando’s inland Valley heat, regularly exceeding 100°F in summer, means these thin-walled garages with uninsulated slabs and former roll-up door openings almost always fail Title 24 energy compliance without a full insulation build-out and a properly sized mini-split system.

Attached Garage Conversion
Attached garage conversions in San Fernando run $95,000-$140,000. The shared wall with the main house simplifies some utility routing, but it also means fire separation and sound attenuation requirements are stricter under San Fernando’s Building & Safety Division codes. We treat the permit set as the core product, engineering the fire-rated assembly and ventilation paths before construction starts so the plan check moves cleanly.

Garage JADU
A Junior ADU conversion inside an existing San Fernando garage, with owner occupancy required in the main house, typically costs $75,000-$115,000. These projects are capped at 500 square feet and share utility connections with the primary residence, which keeps costs down but requires careful load calculations on those older electrical panels. San Fernando’s JADU ordinance has specific owner-occupancy and exterior entrance requirements that we build into the permit set from the first drawing.

Garage Partition & Bathroom Add
Some San Fernando homeowners want to keep part of the garage for storage or parking while converting the remainder to living space. A partition with bathroom addition runs $85,000-$125,000, depending on how the sewer line routes from the existing cast-iron or galvanized drain. These projects require particular attention to San Fernando’s setback and lot coverage rules on these small 1940s-1960s parcels.

Carport Conversion
Carport conversions in San Fernando start around $105,000-$150,000. Without existing walls or a slab designed for enclosed use, we’re essentially building from the foundation up, which surfaces the same Sylmar-era foundation issues we see on detached garages. The upside is a clean slate for Title 24 compliance.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in San Fernando
Ellery ADU Studio specifies and coordinates prefab and modular systems within our single-contract design-build model. In San Fernando, we regularly integrate Cover units for compact detached conversions where site access is tight, and we size Dvele and Mighty Buildings systems for homeowners who want factory precision on the envelope with local finish work. James Hardie siding appears frequently on our San Fernando conversions, specified for its performance in the Valley’s thermal cycling. Every brand is coordinated under one written price, one permit set, one point of accountability.
Common Garage Conversion ADU Problems We See in San Fernando Homes

- Permits submitted to LADBS instead of San Fernando Building & Safety. Contractors assume this encircled city falls under Los Angeles jurisdiction. It doesn’t. The wrong submission costs weeks and sometimes requires a complete re-submittal under San Fernando’s distinct ordinance.
- Title 24 energy compliance failures on detached garages. Thin stucco-over-wood walls, uninsulated slabs, and open roll-up door frames that once let 100°F+ heat pour through cannot meet current code without significant insulation build-out and a correctly sized mini-split. We engineer this into the permit set, not discover it at inspection.
- Sub-100-amp electrical service and galvanized drains behind the stucco. Opening walls on 1940s-1960s construction surfaces outdated systems that must be upgraded to current California ADU permitting thresholds. We inspect for this before quoting and write allowances into the contract.
- Unremediated 1971 Sylmar earthquake damage. Cracked slabs, shifted mudsills, and deteriorated anchor bolts are routine findings on San Fernando’s older detached garages. We budget for foundation repair discoveries that would be far less common a few miles west in Sherman Oaks or Van Nuys.
Pricing for Garage Conversion ADU in San Fernando, CA
| Service | Typical Range (all-in) |
|---|---|
| Garage JADU | $75,000 - $115,000 |
| Attached Garage Conversion | $95,000 - $140,000 |
| Garage Partition & Bathroom Add | $85,000 - $125,000 |
| Carport Conversion | $105,000 - $150,000 |
| Detached Garage Conversion | $110,000 - $165,000 |
These ranges reflect San Fernando’s specific conditions: older housing stock, inland Valley climate loads, and the foundation repair allowances that honest contractors build in. Under Haven Standard Clause 1, every project receives a written price before any work starts. Under Clause 5 (No Surprises), the scope is locked at signing. If we open walls and find something unexpected, we price it in writing, obtain your written approval, and only then proceed. The original quote does not move without your explicit sign-off. Call (661) 528-5298 for your written estimate.
We Also Serve Cities Near San Fernando

Our crews work throughout the north Valley and Santa Clarita corridor, including Garage Conversion ADU in San Fernando proper as well as Sylmar, Tujunga, Santa Clarita, and Stevenson Ranch. Each jurisdiction has its own ADU ordinance and permit counter. We maintain current knowledge of all of them.
Serving San Fernando, CA - Our Local Coverage Area
We’re based in the San Fernando area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Garage Conversion ADU in San Fernando

You submit to the City of San Fernando’s own Building & Safety Division, not LADBS. San Fernando is an independent city of 2.4 square miles completely surrounded by Los Angeles, with its own ADU ordinance, plan-check staff, and inspection schedule. Submitting to LADBS is the most common and costly mistake out-of-town contractors make here. Call (661) 528-5298 and we’ll confirm your exact permit path before any drawings begin.
Detached garages here were built as unconditioned storage, not living space. Thin stucco-over-wood walls, uninsulated concrete slabs, and former roll-up door openings leak heat badly in a climate that regularly exceeds 100°F. Title 24 compliance requires a full insulation build-out, proper air sealing, and a correctly sized mini-split system sized for the Valley’s cooling load. We engineer all of this into the permit set before construction starts. Call (661) 528-5298 for a written quote that includes the full energy package.
We inspect for it first, write specific allowances into your contract, and if we find more than expected, we stop, photograph everything, price the repair in writing, and obtain your written approval before proceeding. On a recent Maclay Avenue conversion, we found a mudsill shifted off its stem wall with rusted anchor bolts, almost certainly 1971 Sylmar damage hidden by decades of stucco. We brought in an engineer, priced the foundation and slab repair, got written approval, then completed the permitted JADU. No work moves without your sign-off. Call (661) 528-5298 to schedule an inspection-first estimate.
Yes. San Fernando was the named epicenter of that earthquake, and many older detached garages and rear structures still show unremediated foundation cracking, shifted mudsills, or deteriorated anchor bolts. We routinely budget for these discoveries, which would be far less common just a few miles west. Our written quotes include foundation repair allowances based on what we find during initial inspection. Call (661) 528-5298 and we’ll assess your specific structure.
A full ADU is an independent dwelling up to 1,000 square feet (or more under certain state rules) with its own kitchen, bathroom, and utility connections, and no owner-occupancy requirement. A JADU is capped at 500 square feet, must be contained within the existing structure, requires owner occupancy in the main house, and can share utility connections. In San Fernando’s small lots and older housing stock, the JADU path often fits better but triggers specific San Fernando Building & Safety requirements for exterior entrances and fire separation. We determine the optimal path during your free estimate. Call (661) 528-5298 to discuss which applies to your property.
Ready to convert your San Fernando garage into permitted, income-producing space? Call (661) 528-5298 to schedule your free estimate. You’ll receive a written price before any work starts, a documented photo record on every visit, and our 365-Day Done Right Promise, all governed by The Haven Standard.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving San Fernando since 2015.