ADU in Glendale, CA
An ADU in Glendale, CA typically runs $165,000-$420,000 all-in for a detached unit, drawings through final inspection, while a garage conversion lands between $95,000 and $240,000 depending on the condition of the existing structure. The work here is shaped less by square footage than by where your lot sits: a flatland bungalow in Adams Hill permits differently from a hillside lot in the Verdugo foothills, and the gap between the two can be $80,000 or more. Ellery ADU Studio handles design, permitting, and construction under one contract with a written price before work starts, so you can reach us at (971) 497-2402 to schedule a free estimate.
Why Glendale Homes Are Different
Glendale’s flatlands are dense with 1920s-1950s Craftsman bungalows and Spanish Colonial Revival homes, most sitting on 5,000-7,000 square foot lots with detached single-car garages at the rear. Those garages are often the fastest path to an ADU, but the slab thickness and foundation condition vary block by block, and we’ve seen everything from clean 4-inch slabs ready for conversion to cracked, settling pads that need full replacement before framing can start.
The other Glendale reality is fire code. Large portions of upper and hillside Glendale fall within CalFire’s Very High Fire Hazard Severity Zone, which mandates Chapter 7A compliance: Class A roofing, ember-resistant vents, and ignition-resistant exterior cladding. Flat-area contractors regularly underbid these requirements because they rarely see them. We specify them in the permit set from day one, so the written price already includes what the hillside inspector will require. The same terrain that drives fire code also drives soils reports, retaining walls, and hillside grading permits on the higher lots above Glenoaks and into the Verdugo foothills.
Our Main Glendale Services
Two services generate the most calls from Glendale homeowners: converting an existing garage on a flatland lot, and building a new detached ADU where the rear alley or a larger hillside lot allows it. Each has its own Glendale-specific page.
Garage Conversion ADU in Glendale
Glendale’s pre-1960 housing stock means most garages were built to store one car and little else, which is actually good news: the footprint is small enough to qualify for streamlined JADU or ADU permitting, and the walls are usually already inside the setback envelope. The condition of the slab, the existing electrical service, and whether the garage shares a wall with the house drive the final price more than anything else. We’ve converted detached alley-facing garages in Kenilworth into fully independent units with their own address and entrance, something the alley grid makes possible in ways Burbank’s street pattern doesn’t. Read the full breakdown on our Garage Conversion ADU in Glendale page.

New Detached ADU in Glendale
A new detached ADU in Glendale gives you control over ceiling height, insulation, and layout from the first line on the drawings, but it also triggers the full permit path: setbacks, lot coverage, fire code where applicable, and in the foothills, soils and grading review. On alley-served blocks like those around Mariposa and Adams Hill, a detached unit can face the alley with its own address, rental privacy, and a separate utility path. On hillside lots, expect retaining walls and possibly two to four months of additional permit time. The full scope is covered on our New Detached ADU in Glendale page.

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 Glendale

ADU Design & Permitting in Glendale is where most projects win or lose money before a single nail is driven. The 1920s-1950s housing stock means original survey lines, lot coverage, and setback measurements rarely match what the county assessor’s site shows, and hillside parcels add CalFire Chapter 7A requirements that a flatland-only designer will miss in the bid. A permit set that anticipates three rounds of corrections costs $9,000-$35,000 here; one that doesn’t can add $40,000 or more in unplanned revisions, redesign, and stalled inspections. Our ADU Design & Permitting team produces the drawings, the energy calcs, and the written scope under one contract, with a documented photo record on every visit and a price locked before work begins.
Site Assessment
Signs you need it
The lot slopes more than a foot across the build area, the garage slab shows cracks wider than a dime, or the assessor’s parcel map doesn’t match the fence lines you actually see.
What it costs in Glendale
A full site assessment for a Glendale ADU runs $2,800-$7,500 depending on whether we’re pulling a topo survey, checking soils, or just verifying existing conditions on a flatland lot.
How we do it
We measure the existing structures against the recorded parcel, check the slab and foundation where a conversion is in play, and flag fire-zone requirements before a single drawing is started.
ADU Design & Blueprints
Signs you need it
You need a plan for a detached ADU, a garage conversion, or a JADU, and you want the drawings to match what the Glendale Building and Safety division will actually approve without three rounds of resubmission.
What it costs in Glendale
Design and blueprint work for a Glendale ADU runs $6,000-$18,000 for a standard unit, with hillside lots and custom multi-story designs pushing toward the upper end.
How we do it
We draft from the site assessment, spec the Chapter 7A assemblies where your lot requires them, and deliver a permit set you can read and review before it ever reaches the city counter.
Permit Application
Signs you need it
You have drawings from a previous designer but the permit application stalled, or you’re starting fresh and want someone competent handling the Glendale submittal, corrections, and resubmittal loop.
What it costs in Glendale
Full permit application service in Glendale runs $1,500-$4,500 in our labor, plus the city’s own filing and plan-check fees which are billed separately and itemized in the written scope.
How we do it
We assemble the package, submit to Glendale, respond to plan-check comments in writing, and log every correction so you can see exactly what changed and why.
What ADU Design & Permitting Costs in Glendale
| Item | Typical range in Glendale |
|---|---|
| Site assessment | $2,800 - $7,500 |
| Design & permit set | $15,000 - $38,000 |
| Permit filing & plan-check management | $1,500 - $4,500 |
How long does Glendale plan check take for an ADU?
Flatland ADUs in Glendale typically clear plan check in 4-6 months from first submittal to issued permit. Hillside lots with fire-zone and grading review can run 8-14 months. A complete, compliant permit set is the only thing that shortens this.
Will the design price change once permitting starts?
No, under Haven Standard Clause 5, the design and permitting scope is locked at signing. If the city requires a change to the drawings, we make it without a change order, and you’ll see the revision tracked in your photo record.
Junior ADU & Interior Conversion in Glendale

Junior ADU & Interior Conversion in Glendale converts space you already own: the unfinished basement, the bonus room off the carport, the second living room nobody sits in. Glendale’s 1920s-1950s stock often includes exactly these rooms, and a JADU permit is the fastest, cheapest legal dwelling unit you can add to a single-family lot, often clearing plan check in weeks rather than months. The catch is the 500-square-foot JADU ceiling and the requirement that you live in one of the two units, which matters for how you think about the project. Our Junior ADU & Interior Conversion scope covers the drawings, the permit, and the construction under one written price.
Interior JADU
Signs you need it
A bedroom and living space share a wall with the main house and you want a legal, rentable unit without adding new square footage or touching the exterior envelope.
What it costs in Glendale
An interior JADU conversion in Glendale typically runs $60,000-$140,000, the lowest-cost ADU path available, with the range driven by kitchen and bath plumbing proximity to existing lines.
How we do it
We draw the JADU boundaries, file with Glendale, install the required efficiency kitchen and the separate entrance where the floor plan allows, and close permits within the same contract.
Room-to-ADU Conversion
Signs you need it
A den, office, or oversized laundry room sits unused and already has at least one exterior door within the setback envelope, and you want it converted to a legal dwelling unit rather than a permitted room.
What it costs in Glendale
A room-to-ADU conversion in Glendale runs $80,000-$180,000 depending on whether new sewer and water lines must be run to reach the room’s location.
How we do it
We trace the plumbing and electrical paths from the existing service, spec the ceiling height and egress compliance, and build the unit without disturbing the main house’s daily function.
What Junior ADU & Interior Conversion Costs in Glendale
| Item | Typical range in Glendale |
|---|---|
| Interior JADU | $60,000 - $140,000 |
| Room-to-ADU conversion | $80,000 - $180,000 |
| Attached addition ADU | $130,000 - $300,000 |
Does a Junior ADU in Glendale require a separate address?
No, JADUs share the main house address and are permitted as accessory living space, not a separate dwelling. Glendale does not assign a second address to a JADU, though a detached ADU on an alley can receive its own.
Do I have to live in the main house with a JADU?
Yes, Glendale follows state law requiring owner occupancy of either the main house or the JADU. If you plan to rent both units long-term, a detached ADU is the better permit path. Call (971) 497-2402 to discuss which fits your lot.
ADU Site Prep & Utilities in Glendale

ADU Site Prep & Utilities in Glendale covers everything between the property line and the foundation: grading, trenching, electrical service, gas, sewer, and the retaining walls that hillside lots demand. The flatlands hide their own surprises, from 1920s clay sewer laterals to 60-amp panels never intended for a second dwelling, and the foothills add engineered retaining walls and soils reports to the same scope. We pull the permits, coordinate the trenching, and upgrade the service under the same written price as the rest of the build, which means the utilities are designed for the ADU from the first drawings, not bolted on after framing. See ADU Site Prep & Utilities for the full breakdown.
Foundation & Grading
Signs you need it
The build site slopes more than 10%, the soil report reveals expansive clay, or the existing garage slab is cracked, settling, or too thin to carry a dwelling unit.
What it costs in Glendale
Foundation and grading for a Glendale ADU runs $28,000-$62,000 for a standard flatland slab, with hillside retaining walls adding $10,000-$40,000 depending on height and engineering.
How we do it
We order the soils report, engineer the slab or pier system to the report, set the forms and rebar, and schedule the Glendale foundation inspection before any concrete is poured.
Electrical Panel Upgrade
Signs you need it
The main panel is 100 amps or less, the ADU will run an HVAC system plus kitchen appliances, or the existing service drop can’t carry the additional load without tripping.
What it costs in Glendale
A 200-amp panel upgrade plus the subpanel feed to a Glendale ADU runs $3,500-$16,000, with the wide range driven by whether Glendale Water & Power requires a service-drop rebuild or the panel can be swapped in place.
How we do it
We size the load calc from the permit set, pull the electrical permit, perform the panel swap, and route the ADU subpanel feed through the same trench line where possible.
What ADU Site Prep & Utilities Costs in Glendale
| Item | Typical range in Glendale |
|---|---|
| Foundation & grading | $28,000 - $62,000 |
| Electrical panel upgrade | $3,500 - $16,000 |
| Plumbing & utility trenching | $8,000 - $25,000 |
Does hillside Glendale always require a soils report for an ADU?
Yes, any Glendale parcel with a slope above 10% or inside a mapped landslide zone requires a geotechnical soils report before the permit set is complete. Budget $3,000-$8,000 for the report, plus any foundation engineering it drives.
Can the utility trench be shared with the main house?
In most flatland Glendale lots, yes. We run the new water, sewer, and electrical conduits in a single shared trench where separation codes allow, which cuts excavation cost by 30-50% compared to three separate trenches.
Brands We Service in Glendale

We specify and coordinate prefab and modular systems from Abodu, Cover, Dvele, and Mighty Buildings within our Glendale projects, holding drawings for each system in-house so the permit set arrives ready for their engineering requirements. Component lead times for these brands run 8-24 weeks, and we order panels and modules at permit acceptance to keep the construction schedule moving.
Pricing for ADU in Glendale, CA
| Service | Typical range in Glendale |
|---|---|
| Site assessment | $2,800 - $7,500 |
| Design & permit set | $15,000 - $38,000 |
| Permit filing & plan-check management | $1,500 - $4,500 |
| Interior JADU | $60,000 - $140,000 |
| Room-to-ADU conversion | $80,000 - $180,000 |
| Attached addition ADU | $130,000 - $300,000 |
| Foundation & grading | $28,000 - $62,000 |
| Electrical panel upgrade | $3,500 - $16,000 |
| Plumbing & utility trenching | $8,000 - $25,000 |
| Garage conversion ADU (all-in) | $95,000 - $240,000 |
| New detached ADU (all-in) | $165,000 - $420,000 |
Hillside work pushes every line item up: fire-zone cladding, retaining walls, soils reports, and the additional plan-check time all compound. The written price you receive covers the full scope at signing, and under Haven Standard Clause 5, that price does not change unless you change the scope.
Neighborhoods We Serve in Glendale

Our crews work across Glendale weekly, from the alley-served flatland blocks to the hillside lots above Glenoaks Boulevard. Typical response for an on-site visit is 2-4 business days from your call.
- Adams Hill
- Kenilworth
- Mariposa
- Verdugo foothills
- City Center
Service Area - Cities Near Glendale
We serve Glendale and the surrounding communities, including Burbank, CA, Universal City, CA, North Hollywood, CA, and Tujunga, CA. Scheduling and dispatch are coordinated from our Los Angeles office; crews serve Glendale locally.
Serving Glendale, CA - Our Local Coverage Area

We’re based in the Glendale 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 Glendale
Site assessment happens within 2-4 business days of your call, and design work begins as soon as the assessment is done and the written price is signed. The limiting factor in Glendale is almost always plan check, not our availability, and a complete permit set is the best hedge against a stalled review.
Most Glendale single-family lots are not under an HOA, but some newer subdivisions and gated foothill communities are. If an HOA is present, we pull the architectural guidelines during the site assessment and flag any approval step so it runs parallel to the city permit, not after it.
Yes, drawings, permits, and construction are a single contract with one written price. There is no separate designer and no separate builder to point at each other when a plan-check comment comes back or a framing detail is wrong. If it’s not right, we make it right under the 365-Day Done Right Promise.
Call (971) 497-2402 to schedule a free estimate on your Glendale ADU project, or to get a free second opinion on a written bid you already have in hand.
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 Glendale Customers Say
"Garage conversion finished on the drawings and close to the schedule. They were honest that the sewer connection was the unknown, and it was."
- Arjun D."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.