Fast, Reliable New Detached ADU Across Daly City
Most homeowners in Daly City who start out searching for a “new detached ADU” end up building something different: a garage conversion, a tuck-under reconfiguration, or an interior remodel that adds a legal unit without touching the property line. The reason is simple and specific to this city. Daly City’s post-WWII hillside tract homes sit on lots as small as 2,500 sq ft with shared party walls, making true detached ADUs infeasible on most parcels, unlike neighboring South San Francisco or Pacifica where larger lots often allow them. That reality shapes everything we do here. We’re Ellery ADU Studio, a design-build studio founded in 2015, and our New Detached ADU team has designed, permitted, and built across Daly City’s Westlake, St. Francis Heights, and Broadmoor neighborhoods. Every project we take on starts with a written price before any work begins, and every client receives a documented photo record of what we find when walls come open. Call (971) 497-2402 to schedule a free estimate.
Why Ellery ADU Studio Is Daly City’s Preferred New Detached ADU Company
Nadia Ellery founded this studio the year California’s ADU permitting landscape shifted, and she built the practice around a single contract covering drawings, permit set, and construction, so there is no designer-versus-builder blame gap when something goes sideways. That matters in Daly City, where the gap between what a homeowner imagines and what the lot actually allows is wider than almost anywhere else in San Mateo County.
We have worked on hundreds of Daly City properties. We know the Westlake District’s attached stucco rows, the hillside grading in St. Francis Heights, the fog patterns that keep west-facing Broadmoor walls damp for months at a time. Our clients in Daly City consistently mention two things in reviews: the permit set is the core product we deliver, and the written price we quote is the price they pay. Under Haven Standard Clause 1, every project is quoted with a written price before any work begins. No door-side upsells, no scope creep. We also document every visit with photos, so you see exactly what we found behind the drywall, not a summary of how it felt. Nadia Ellery has built this practice on evidence, and the evidence is in the documentation you receive.
Our New Detached ADU Services in Daly City
Here is the honest version of what “new detached ADU” work looks like in Daly City. On the rare parcel with enough side and rear clearance, we design and build a truly detached unit. On most parcels, we deliver the same outcome, a legal, rentable unit, through a garage conversion or tuck-under reconfiguration that works within the lot’s existing footprint. These are the four service paths we handle most often.
Custom Built ADU
A custom built ADU in Daly City almost always means working within an existing structure: the street-facing tuck-under garage, the basement-level space beneath the main living floor, or an attached wing with a shared party wall. We design to the actual conditions of your lot and your existing framing, not to a catalog plan that assumes a flat suburban parcel. The permit set reflects every existing condition we document, so the city’s plan reviewer sees exactly what we see.
Studio ADU
Studio ADUs are the most common unit type in Daly City’s hillside tracts, because they fit within the compact footprints of 1940s and 1950s garages without triggering major structural changes. On a 400 sq ft tuck-under in the Westlake District, for example, a studio layout with a single wet wall keeps plumbing runs short and avoids cutting into load-bearing framing. We specify mechanical ventilation and vapor barriers as standard here, not as upgrades, because Daly City’s persistent marine layer punishes any studio that lacks them.
1-Bed & 2-Bed ADU
When the existing garage footprint allows, we design one- and two-bedroom units that give you flexibility as a rental or a long-term family space. In Daly City, this usually means working with the sloped cut-and-fill pads these homes were built on. We frequently find that a garage slab drains toward the back wall rather than away from it, which means the bedroom-to-be would sit in a moisture trap. We address that in the permit set and in the written scope before framing starts, under Haven Standard Clause 5, no surprises, no mid-project scope changes unless you approve them in writing.
We also handle New Detached ADU in Daly City projects that involve prefab and modular coordination, working within the same single contract to specify and coordinate systems from brands like Cover, Dvele, and Mighty Buildings. If a modular unit fits your lot’s constraints, we handle the site prep, utility connections, and finish work under the same written price.
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 Daly City
Our team specifies and coordinates prefab and modular ADU systems from Cover, Dvele, and Boxabl among others, within the same single contract that covers your site work and utilities. We do not sell you a brand. We evaluate the lot, the grading, the existing utility capacity, and the city’s permitting requirements, then recommend a system that actually fits. For Daly City’s hillside parcels, that often means a panelized or volumetric system that can be placed without heavy crane access through narrow Westlake streets. We coordinate the brand’s engineering with Daly City’s building department directly, so you are not stuck translating between a factory spec sheet and a city plan checker.
Common New Detached ADU Problems We See in Daly City Homes
Opening up a 1940s or 1950s Daly City home for ADU work turns up the same set of problems on a remarkable number of jobs. Here is what we encounter most often, and how we handle each one.
- Original slab drainage pooling under habitable floors. The tuck-under garages in Daly City’s hillside tracts were often built on cut-and-fill graded pads in the 1940s and 1950s, and contractors frequently discover that slab drainage is directed toward, not away from, the garage interior once they open up the floor. Re-sloping or installing interior French drains becomes a necessary mid-project cost on a significant share of jobs.
- Outdated wiring that cannot handle modern loads. A 1955 garage typically has a single 15-amp circuit. An ADU with a kitchen, bathroom, and HVAC needs a new subpanel and often a service upgrade, which triggers an electrical permit and potentially a PG&E service change at the street. We write this allowance into the contract before we start, not after we find it.
- Moisture intrusion and failed waterproofing in fog-exposed walls. Daly City is one of the foggiest cities in the continental US, with persistent Pacific marine layer keeping humidity consistently high and limiting direct sunlight, especially on west- and north-facing slopes. Garage conversions that lack mechanical ventilation and vapor barriers routinely develop chronic moisture intrusion and mold within a few years. We specify robust HVAC and waterproofing as non-negotiable standard work.
- Zero side or rear setback clearance forcing a mid-plan redesign. A contractor prices a detached ADU on a 2,800 sq ft hillside lot only to discover the city will not approve any structure within the required setback distances. That forces a redesign into a garage conversion after the permit application was already filed. We check setbacks first, before any plans are drawn, because the alternative wastes months and money.
On a hillside street in the Westlake District, our crew opened up a 1950s tuck-under garage for a new detached ADU plan and found the original slab poured on a cut-and-fill pad draining straight toward the back wall. Moisture had already wicked under the framing. We wrote a change order for re-sloping and an interior French drain before any framing went in, keeping the owner out of a mold-prone build and the permit inspector satisfied. That is what a proper inspection-first approach looks like in Daly City.
Pricing for New Detached ADU in Daly City, CA
Here are the real numbers for the Daly City market, based on our completed projects since 2015. A garage-to-studio ADU conversion in Daly City typically runs $180,000 to $260,000 all-in, drawings through final inspection. A one-bedroom conversion with a full kitchen and bathroom typically runs $240,000 to $320,000. A two-bedroom unit, which usually requires more structural work in the tuck-under footprint, runs $300,000 to $400,000. Drainage correction, electrical service upgrades, and structural reinforcement account for the spread between the low and high ends on any given project.
Every one of our Daly City projects starts with a written price before any work begins, under Haven Standard Clause 1. The words “call for a quote” do not appear anywhere on this site. What you get is a written scope, a written price, and a Free Second Opinion on any written estimate you already have in hand. Call (971) 497-2402.
We Also Serve Cities Near Daly City
Our crews serve Daly City and the surrounding San Mateo County and San Francisco Bay Area communities, including South San Francisco, San Bruno, Pacifica, and San Francisco. Each city runs its own building department with its own ADU ordinance framework, and we hold our permit sets to whichever jurisdiction applies. If you are in a nearby city and weighing a New Detached ADU, the same written-price guarantee applies.
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 - New Detached ADU in Daly City
Because Daly City’s post-WWII hillside tract homes sit on lots as small as 2,500 sq ft with shared party walls, and most parcels do not have enough side or rear setback clearance to meet the city’s requirements for a standalone structure, while Oakland’s flatland lots often do. Your cousin’s Oakland lot likely has a larger footprint and deeper setbacks. In Daly City, virtually every “new detached ADU” request ends up as a garage conversion or a reconfiguration of the existing tuck-under footprint, which delivers a legal, rentable unit under the same ADU ordinance without violating setback rules. Call (971) 497-2402 and we will check your parcel’s setbacks before any plans are drawn.
You follow Daly City’s building department rules, not San Francisco’s, even if your property is within sight of the border. Daly City operates its own building department under San Mateo County’s ADU ordinance framework, which means different fee schedules, inspection timelines, and owner-occupancy history requirements than San Francisco’s, and a project planned around San Francisco’s assumptions often stalls or gets rejected mid-plan. We prepare every permit set to the exact jurisdiction that governs your address. Call (971) 497-2402 for a written price on a permit set built for Daly City’s process.
It is more likely than not, because the tuck-under garages in Daly City’s hillside tracts were built on cut-and-fill graded pads with slab drainage frequently directed toward the garage interior, and once we open the floor for habitation work we often find moisture already present, which means re-sloping or an interior French drain becomes a necessary part of the permit scope. We write drainage correction into the written price whenever a pre-construction inspection indicates the risk. Call (971) 497-2402 and we will document what your slab is actually doing before the contract is signed.
Daly City’s building department reviews ADU plans against its own interpretation of San Mateo County’s ADU ordinance framework, which often requires additional documentation for hillside grading, cut-and-fill pad stability, and drainage that flatland cities do not ask for, and those reviews add weeks to the plan-check timeline. We prepare the permit set anticipating those specific reviewer concerns, which is the single most effective way to keep a Daly City permit moving. Call (971) 497-2402 and we will walk you through what your specific project will require.
Yes, and robust mechanical ventilation plus a proper vapor barrier is standard on every Daly City ADU we build, regardless of size, because the city’s persistent marine layer keeps humidity high enough that a garage conversion without them will develop moisture and mold within a few foggy seasons. We specify HVAC and waterproofing as non-negotiable standard work, never as an optional upgrade. Call (971) 497-2402 for a written price that includes the ventilation your unit will actually need.
Contact Ellery ADU Studio in Daly City
If you are weighing a new detached ADU in Daly City, or the garage conversion that most Daly City parcels actually require, call (971) 497-2402 to schedule a free estimate. You will get a written price before any work begins, a documented photo record on every visit, and a 365-Day Done Right Promise in writing. If you already have an estimate from another contractor, bring it to us for a Free Second Opinion. We will tell you what the permit set actually requires and what the work will actually cost.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Daly City with written-price ADU design and construction since 2015.