ADU in Daly City, CA
ADU Design & Permitting in Daly City almost always means converting a tuck-under garage inside a 1940s-1960s stucco tract home, because lots under 4,000 sq ft with shared party walls leave no room for a detached unit. The fog that rolls through the Westlake District and Crocker neighborhoods keeps humidity high year-round, so a conversion that works fine in a drier city will develop mold in Daly City unless the ventilation and waterproofing are designed from the start. Ellery ADU Studio handles the drawings, the permit set, and the construction as one contract at one written price, and you can reach us at (971) 497-2402 for a free estimate.
Why Daly City Homes Are Different
Daly City’s housing stock was built fast after WWII: row after row of attached and semi-attached stucco homes on narrow hillside lots, many in the Westlake District, with street-level tuck-under garages beneath the main living floor. That garage is the ADU opportunity here. The cut-and-fill graded pads those garages sit on were built in the 1940s and 1950s, and once we open the floor for habitation work we regularly find slab drainage directed toward the garage interior, not away from it. Homeowners adjacent to San Francisco often assume they fall under SF’s permitting rules, but Daly City runs its own building department under San Mateo County’s ADU ordinance framework, which means a different fee schedule, different inspection timelines, and its own owner-occupancy history requirements. The persistent Pacific marine layer compounds everything: west- and north-facing slopes get little direct sun, and a garage conversion without mechanical ventilation and a vapor barrier will show moisture intrusion within a few years.
Our Main Daly City Services
Two services account for nearly every ADU project we quote in Daly City: garage conversions and, where lot sizes allow, new detached units.
Garage Conversion ADU in Daly City
Most Daly City ADUs are garage conversions because the tuck-under garage is the only square footage that does not require adding a foundation on a slope. The dominant Westlake-era tract homes already have the garage under the living floor, which means the roof, two walls, and often a side wall already exist. What the conversion requires is re-sloping the slab, adding waterproofing and ventilation for the fog belt, and upgrading the electrical panel to support a kitchen and bath. See the full breakdown on our Garage Conversion ADU in Daly City page.
New Detached ADU in Daly City
A new detached ADU in Daly City is viable on larger lots, typically those over 5,000 sq ft in the Southern Hills or St. Francis Heights neighborhoods, where rear setbacks allow a separate structure. On smaller Westlake lots, the numbers usually do not work: setback variance requests, grading costs, and utility trenching can add $40,000 before framing starts. Our New Detached ADU in Daly City page covers what makes a detached build pencil out here.
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.
ADU Design & Permitting in Daly City
Getting a Daly City ADU through design and permitting means producing a permit set that the City’s building department will approve without rounds of corrections, on a site constrained by a small hillside lot and a tuck-under garage that predates current code. The ADU Design & Permitting work we do here starts with a site assessment that flags the drainage and vapor-barrier issues unique to the fog belt before they become expensive surprises during rough-in.
Site Assessment
Signs you need it
You’re considering a garage conversion or interior reconfiguration on a hillside lot and want to know whether the existing slab, drainage, and party-wall conditions will support an ADU.
What it costs in Daly City
A site assessment in Daly City runs $450-$950, including a written findings report with photos.
How we do it
We inspect the garage slab pitch, shared party walls, sewer lateral location, panel capacity, and fog-zone moisture conditions, then deliver a written report with a documented photo record.
Permit Application
Signs you need it
You have a design you like but the permit package keeps getting bounced back by the Daly City building department for missing details or code conflicts.
What it costs in Daly City
Full permit-set production and submission in Daly City typically runs $4,000-$9,500 depending on scope, plus city fees paid directly to Daly City.
How we do it
We produce the architectural drawings, Title 24 energy calculations, structural details, and site plan as one package, submit it to Daly City, and respond to plan-check comments until the permit is issued.
What ADU Design & Permitting Costs in Daly City
| Item | Typical range in Daly City |
|---|---|
| Site assessment with written report | $450-$950 |
| Full permit set (drawings, Title 24, structural) | $4,000-$9,500 |
| Permit expediting and plan-check response | $1,500-$3,200 |
How long does ADU design and permitting take in Daly City?
Plan for 8-14 weeks from first site visit to issued permit in Daly City, depending on plan-check backlog and whether a variance is required. A complete permit set avoids most correction cycles. Call (971) 497-2402 for a current timeline.
Does Daly City require owner occupancy for an ADU?
Daly City follows San Mateo County’s ADU ordinance framework, which imposes owner-occupancy requirements for certain ADU types. We verify the requirement that applies to your specific project before you commit. Call (971) 497-2402 for a free estimate.
Junior ADU & Interior Conversion in Daly City
Junior ADU & Interior Conversion in Daly City turns unused interior space, often a basement-level room or an oversized primary bedroom, into a rentable or family unit without adding square footage to the footprint. Because most Daly City parcels cannot accommodate a detached structure, Junior ADU & Interior Conversion is frequently the most practical path to a second unit in this city.
Interior JADU
Signs you need it
You have a finished room or basement-level space with a separate exterior door or an easy path to add one, and you want a rentable unit without a full addition.
What it costs in Daly City
An interior JADU in Daly City typically runs $60,000-$110,000 all-in, depending on whether a kitchenette and bath are added or already stubbed.
How we do it
We assess egress, fire separation, and ventilation requirements for the fog zone, then build out the JADU under one contract at one written price.
Room-to-ADU Conversion
Signs you need it
You have a large interior room or attached sunroom that is underused, and you want to convert it to an independent living space with its own entrance and kitchenette.
What it costs in Daly City
Room-to-ADU conversions in Daly City run $80,000-$140,000 depending on plumbing runs, kitchenette scope, and whether the new entrance requires header work on a hillside wall.
How we do it
We redesign the space, pull the permit, add the required fire separation and ventilation, and convert the room to a code-compliant unit with a documented photo record.
What Junior ADU & Interior Conversion Costs in Daly City
| Item | Typical range in Daly City |
|---|---|
| Interior JADU with kitchenette and bath | $60,000-$110,000 |
| Room-to-ADU conversion with new entrance | $80,000-$140,000 |
| Fire separation and egress upgrades | $5,000-$15,000 |
Is a Junior ADU the fastest way to add a unit in Daly City?
Yes, a JADU typically clears Daly City permitting faster than a full ADU because it uses existing interior space and does not require a new foundation or setback relief. Call (971) 497-2402 for a free estimate.
Can I use a basement space as a JADU in Daly City?
Yes, if the space meets egress and ceiling-height requirements and has a compliant entry path. Many Daly City tuck-under garage homes have basement-level rooms that work well. Call (971) 497-2402 for a site assessment.
ADU Site Prep & Utilities in Daly City
ADU Site Prep & Utilities in Daly City means solving the hillside and fog-belt issues that turn a simple conversion into a water-damaged unit: slab drainage, vapor barriers, panel capacity, and sewer laterals. The ADU Site Prep & Utilities work we do on Westlake and Crocker area homes starts with the assumption that the 70-year-old site drainage was never designed for habitable space at grade.
Foundation & Grading
Signs you need it
Your tuck-under garage floor slopes toward the interior, or you see efflorescence and dampness at the slab edge after a wet winter.
What it costs in Daly City
Foundation re-sloping or interior French drain installation in Daly City runs $9,000-$25,000 depending on slab area and whether structural underpinning is needed.
How we do it
We open the slab, correct the drainage direction, install waterproofing and a vapor barrier, and re-pour with proper slope before any finish work begins.
Electrical Panel Upgrade
Signs you need it
Your existing panel is 100 amps or less and the ADU will add a kitchen, bath, and laundry loads that exceed capacity.
What it costs in Daly City
Panel upgrades for Daly City ADUs run $4,000-$10,000 including new service wiring and grounding, with the higher end for underground service feeds on hillside lots.
How we do it
We evaluate existing load, specify the upgraded panel and subpanel, submit the electrical permit, and coordinate with PG&E for any service-side work.
What ADU Site Prep & Utilities Costs in Daly City
| Item | Typical range in Daly City |
|---|---|
| Foundation re-slope and interior French drain | $9,000-$25,000 |
| Electrical panel upgrade to 200A | $4,000-$10,000 |
| Vapor barrier and waterproofing | $3,000-$8,000 |
Why does drainage matter so much for ADUs in Daly City?
Daly City’s cut-and-fill hillside pads frequently direct water toward the tuck-under garage interior, and the persistent fog keeps slabs damp. An ADU without corrected drainage will develop mold. Call (971) 497-2402 for a site assessment.
How much electrical capacity does a Daly City ADU need?
Most Daly City homes need a panel upgrade to 200 amps to support an ADU kitchen, bath, and laundry. We determine the exact load calculation during the site assessment. Call (971) 497-2402 for a free estimate.
Brands We Service in Daly City
Ellery ADU Studio specifies and coordinates prefab and modular systems from brands including Abodu, Cover, and Dvele within a single design-build contract, plus James Hardie siding where the design calls for it. Our our brands page lists what we work with and how coordination is handled, including local lead times for Daly City projects.
Pricing for ADU in Daly City, CA
| Service | Typical range in Daly City |
|---|---|
| Site assessment with written report | $450-$950 |
| Full permit set (drawings, Title 24, structural) | $4,000-$9,500 |
| Permit expediting and plan-check response | $1,500-$3,200 |
| Interior JADU with kitchenette and bath | $60,000-$110,000 |
| Room-to-ADU conversion with new entrance | $80,000-$140,000 |
| Fire separation and egress upgrades | $5,000-$15,000 |
| Foundation re-slope and interior French drain | $9,000-$25,000 |
| Electrical panel upgrade to 200A | $4,000-$10,000 |
| Vapor barrier and waterproofing | $3,000-$8,000 |
What pushes ADU pricing up in Daly City is the hillside: re-grading a cut-and-fill pad, trenching utilities through adobe clay, and adding structural support for a tuck-under garage conversion all add line items that flat-lot cities never see. Every Ellery ADU Studio project is quoted with a written price before any work begins, under Haven Standard Clause 1, so the number on your proposal is the number you pay.
Neighborhoods We Serve in Daly City
We serve ADU projects across Daly City, including the neighborhoods where the housing stock and terrain create the most specific conditions. Response time for an initial site visit is typically 2-4 business days within Daly City.
- Westlake District
- Crocker
- St. Francis Heights
- Southern Hills
- Bayshore
Service Area - Cities Near Daly City
Our design-build teams also cover ADU projects in the neighboring communities of South San Francisco, CA, San Bruno, CA, Pacifica, CA, and San Francisco, CA, where the same fog-belt and hillside considerations apply.
Serving Daly City, CA - Our Local Coverage Area
We’re based in the Daly City 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 About ADU in Daly City
A garage conversion of the tuck-under garage is the most practical ADU for most Daly City homes because the structure already exists and no new foundation is needed on the hillside. Detached ADUs are viable only on larger lots with adequate rear setbacks.
Daly City operates under San Mateo County’s ADU ordinance framework, which includes owner-occupancy provisions for certain ADU and JADU types. We verify the specific requirement for your project during the site assessment, before you commit to any design work. Call (971) 497-2402 for a free estimate.
Schedule the initial site assessment 4-6 weeks before you want design work to start, because Daly City plan-check timelines and fog-season construction windows affect the schedule. A documented photo record and written scope at signing keep the timeline predictable. Call (971) 497-2402 to schedule your free estimate.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Daly City Customers Say
"The permit set and the build were one contract with one number. Our neighbours used two firms and spent a year watching them blame each other."
- Helena V."The rental income has covered the payment since the second month. They were realistic about the numbers rather than optimistic."
- Odette N."They walked us through setbacks and utility capacity before we paid anything, and told us one of our two options was not going to get approved."
- Mireille T.