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Westlake
Daly City’s largest and most uniform neighborhood. Doelger split-levels on 25–30 foot lots. Nearly every home is a garage-conversion candidate. High rental demand due to BART access.
Daly City Peninsula Contractor — CSLB #1041528
ADU Construction in Daly City — Building on Doelger-Era Split-Level Lots
Thousands of Doelger homes with front-facing garages—and nearly every one is a candidate for an ADU. We handle design, permitting, and construction for Daly City homeowners.
Daly City Expertise
Daly City’s housing stock is uniform— and uniformly ripe for ADUs.
Daly City occupies a unique position in the Peninsula housing market. The city was built rapidly between 1940 and 1970, with thousands of nearly identical homes on standardized lots. Over 83 percent of Westlake’s homes—the signature Doelger development—were built during that two-decade window. That uniformity is an asset when you’re planning an ADU: every home shares the same construction type, foundation approach, lot dimensions, and setback constraints.
The Doelger split-level is Daly City’s defining housing type. A typical unit sits on a 25-to-30-foot-wide lot, with a single-car garage at street level and living space on the upper floor. Behind the garage is a modest rear yard—20 to 40 feet deep. That configuration creates two immediate ADU construction opportunities: convert the front-facing garage to a studio or one-bedroom, or build a detached unit in the rear yard.
“Daly City isn’t a hillside city like Pacifica. It’s a city of lots that are geometrically simple and construction that’s straightforward. That means you can predict what you’re building into before you break ground.”
We’ve completed dozens of Daly City ADU projects—from garage conversions to detached units in the rear yard. We know the Doelger floor plans, the local permitting requirements, the BART-driven rental market, and the multigenerational families who make up a large part of Daly City’s character.
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San Mateo Specialists
We know San Mateo’s 20+ neighborhoods, their zoning rules, and the best ADU strategies for each.
Market Context
Why ADUs Make Particular Sense in Daly City
$850K
Median Home Price
More affordable than SF, but strong appreciation. ADU investment is compelling for value-conscious owners.
$2,200
Typical ADU Rent
Studio/one-bed units. Premium rates near BART—renters will pay for transit access.
4 ft
Minimum Setback
State law allows tight setbacks on detached ADUs under 800 sq ft. Most Doelger lots qualify.
Daly City’s median home price hovers around $850,000—significantly lower than San Francisco but still reflecting strong Bay Area appreciation. Most homeowners sit on mid-century homes on lots that were subdivided to maximize density. Those homes are aging, many families need additional space, and the rental market is hungry for housing within a ten-minute BART ride to downtown.
A one-bedroom ADU in Daly City can command $2,000 to $2,400 per month. The demand is driven by renters who work in San Francisco, the East Bay, or SFO but can’t afford San Francisco rents. A garage-conversion ADU with its own street-level entrance is ideal for this rental use case. And California law provides a parking exemption for ADUs within half a mile of transit—which most of Daly City qualifies for.
For multigenerational families, the case is even more straightforward: keep an aging parent close without sharing a wall. A garage-conversion ADU provides an independent living situation with its own entrance, bathroom, and kitchenette—all without forcing a major renovation to the main house.
10 min
to Downtown SF via BART
Housing Types & ADU Options
Two Housing Types. Two Clear ADU Paths.
Doelger Westlake · Serramonte · Hillside
Garage Conversion
The front-facing garage is the most practical ADU conversion on a split-level home. The shell already exists—walls, roof, and concrete slab. Converting it involves building habitable interior walls, insulating, adding bathroom and kitchenette, installing independent electrical and plumbing, and replacing the garage door with an entry door or window.
Because the garage sits at street level on the split-level, the ADU has its own entrance separate from the main house—ideal for privacy and rental use. Fire separation between the ADU and the living space above must meet code, typically one-hour fire-rated assembly.
✓
Fastest timeline, lowest cost of entry, and ideal for both rental income and multigenerational families.
Broader Rear Yards · Park Pacifica · Broadmoor
Detached Rear-Yard Unit
Where the rear yard is deep enough (typically 25 feet or more), a detached ADU can be built. Daly City’s allowable height of up to 16 feet for freestanding detached ADUs and 4-foot side and rear setbacks provide a workable envelope on most lots.
On the narrower 25-foot lots common in Westlake, the maximum detached ADU width is constrained to about 17 feet. Wider lots in neighborhoods like Serramonte and Hillside allow for more generous floor plans. The trade-off is straightforward: detached units take longer to build and cost more (new foundation, full MEP systems), but they provide maximum separation and independent access for renters or family members.
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Most Doelger homes are 60+ years old. Existing electrical and plumbing systems may need replacement rather than extension when tying into the main structure.
Permitting
Daly City Permitting — What to Expect
Daly City’s ADU permitting is ministerial—if your project meets the city’s objective development standards, approval isn’t discretionary. You get a hearing officer review, not a conditional use permit. Standard timeline is 30–60 days from application to approval.
Size Limits
Detached ADUs up to 1,200 sq ft. Attached ADUs capped at 850 sq ft (one-bed) or 1,000 sq ft (two+ beds), or 50% of primary dwelling, whichever is greater. Garage conversions inherit the existing garage footprint.
Height Limits
Detached ADUs can match the primary dwelling height or 25 feet, whichever is less. In front of the primary dwelling, the limit drops to 16 feet.
Setbacks
Detached ADUs require 4-foot side and rear setbacks and a 15-foot front setback (20 feet if above a garage). Most Doelger lots accommodate these easily.
Parking
One space may be required, but parking is waived for properties within half a mile of BART—which covers most of Daly City. A converted garage doesn’t trigger replacement parking requirements.
Fire-Rated Walls
Garage conversions require one-hour fire-rated separation from the main dwelling. This is standard on all our Daly City conversions.
Fees
Permit fees for a 500-600 sq ft garage conversion typically run $2,500–$4,000. Detached ADU fees are higher, roughly $4,000–$6,000 depending on square footage.
We recommend a pre-application meeting with Daly City planning before submitting construction documents. This catches potential issues—setback conflicts, utility capacity, tree proximity—before you’ve invested in drawings. We attend these meetings with our clients.
Neighborhoods
Neighborhoods We Build In
- 📍Serramonte
Hillside area with slightly larger lots and more varied home types. Detached ADUs are feasible on many properties. Mixed 1950s–1970s housing stock.
- 📍Hillside
Rolling terrain with homes of varying sizes and vintage. Some properties have generous rear yards suitable for detached units. More custom homes than pure Doelger tracts.
- 📍Broadmoor
Older section of Daly City with pre-Doelger homes dating to the 1920s–1940s. Bungalow and ranch-style construction on slightly larger lots. ADU potential varies by lot.
- 📍Park Pacifica
Southern Daly City neighborhood with 1970s larger homes on more generous lots. Often the straightforward ADU sites. Excellent for detached units.
- ☎Not Sure?
Every lot is different. Call us at (650) 224-3052 and describe your property. We’ll tell you what’s typically feasible in your neighborhood before you schedule a visit.
Investment
What an ADU Costs in Daly City
Daly City construction costs track closely with the broader Peninsula market. Garage conversions are your most affordable entry point; detached units command a premium due to new foundations and utilities.
*All ranges reflect Peninsula market conditions — varies by scope, site conditions, and finish level
Garage Conversion
Existing structure, fastest timeline, lowest cost of entry. Most common on Doelger split-levels.
$120K – $220K+Detached ADU — Standard
New foundation, full utilities, rear-yard placement. Standard timeline 8–12 months.
$250K – $380K+Attached ADU
Shares wall with primary structure. Ideal for multigenerational families.
$180K – $320K+
Costs scale with finishes and square footage. A 500 sq ft garage conversion will be significantly less than a 1,000 sq ft detached unit. The San Mateo County ADU Resource Center estimates total ADU costs at $450–$600 per square foot including design, engineering, and permitting. For a realistic estimate based on your specific lot and home, call (650) 224-3052.
Our Process
Our ADU Construction Process
We cover our full construction process in detail on our ADU Construction hub page. Here’s the summary:
Site Evaluation
We visit your property, assess the lot dimensions, rear yard depth, utility connections, and existing structures. We identify whether a garage conversion or detached unit is the better path—or if both are possible. Free, no obligation.
Design & Engineering
Floor plans, elevations, fire-rated wall specifications (if applicable), structural engineering (for detached units), and Title 24 energy calculations. All under one contract.
Permitting
We prepare and submit the full application to Daly City planning, respond to any plan check comments, and coordinate the hearing officer review. Typical Daly City timeline: 30–60 days.
Construction
For garage conversions: interior walls, insulation, MEP systems, and finishes. For detached units: foundation, framing, MEP, and site restoration. Our crew handles all structural work.
Inspections & C of O
We schedule every required inspection and don’t consider the job complete until you have your C of O. Typical Daly City project: 6–10 months from permit to occupancy.
Why ACI
Why Daly City Homeowners Choose ACI
We know Doelger homes
We’ve completed dozens of Daly City ADU projects. We understand the construction type, the lot constraints, the permitting quirks, and the rental market that drives Daly City demand.
We handle fire-separation details
Garage conversions require one-hour fire-rated walls. That’s not a surprise late in the project for us—it’s baked into our Daly City design and permitting process from day one.
Design-build simplicity
One company, one contract, one person to call. You’re not juggling an architect, engineer, and GC. We cover all of it.
We attend pre-app meetings
We schedule and attend the planning department pre-application meeting with you. This catches issues early, when changes are free, not expensive.
CSLB #1041528
Licensed GC — Class B
Bonded & Insured
Family-Owned