Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Glendale
A permitted home addition or ADU in Glendale typically runs $45,000 to $130,000 depending on scope, and the two factors that shape both the price and the schedule more than anything else are the Chapter 7A fire zone review and the geotechnical soils report. You won’t hear that from a contractor who only builds on flat lots in Burbank. We build on both sides of the 134, so we know exactly what Glendale’s hillside permits demand before we ever order a single long-lead item. Call Barrett & Sons Construction at (877) 610-1318 for a free estimate, and we’ll walk your property with the same checklist Glendale Building and Safety uses.
If you live in Verdugo Woodlands, Chevy Chase Canyon, Montecito Park, or anywhere in ZIPs 91207 and 91208, your project will face a dual regulatory review that most neighboring cities don’t require. We plan for it from day one. If you’re in Adams Hill, Grandview, or Kenneth Village on one of those 1920s Spanish bungalows, your foundation is the conversation we’ll have first. Different neighborhoods, different permit paths, same written scope of work before anything gets ordered.
Why Barrett & Sons Construction Is Glendale’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998, and his sons run the crews that show up in Glendale. It’s not a franchise and nobody is dispatched from out of state. When a Glendale homeowner signs a contract with us, the name on the truck is the name on the permit, and a live person answers our phone 24/7. That matters in a city where the permit counter asks hard questions and the inspector shows up on his own schedule. We don’t hide from either of those things.
Our Glendale customers don’t pick us because we’re the cheapest bid. They pick us because every allowance, every scope item, and every price change arrives as a written change order before work proceeds. The allowance that isn’t on paper is a surprise waiting for a date, and people in Glendale have been surprised enough by the last guy. We also carry the 90-Day Done Right Promise on every job, written on the contract, not buried in fine print. If it’s not done right, Tom comes back and makes it right. One call.
We’ve framed additions on steep cut-and-fill lots up in the Verdugos where the retaining wall engineering alone would scare off a lesser crew. We’ve pulled Chapter 7A fire-resistant permits on hillside ADUs that required ignition-resistant cladding and ember-resistant vents. And we’ve worked on 1920s Spanish Colonial Revival homes in Adams Hill where the original cripple-wall foundation needed seismic retrofit detail before the new square footage ever got framed. That experience means we don’t price a Glendale project like a Van Nuys project and then scramble in week three.
Our Home Additions & ADU Services in Glendale
Here’s what our Home Additions & ADU team handles most often in Glendale. Every line of work below includes permits pulled and inspections signed on every eligible job, with written change orders before anything changes.
ADU Design & Permitting
Glendale ADUs in hillside ZIPs 91207 and 91208 face a permit review most contractors never see: Chapter 7A fire-resistant assembly compliance plus a geotechnical or soils report for any structure on graded terrain. We prepare the package for both sign-offs at once, so your ADU isn’t stuck in plan check for an extra four weeks waiting on a soils engineer who was never on the schedule. For flatland neighborhoods like Grandview or Kenneth Village, the path is often simpler, but we still submit complete drawings the first time because resubmittals are where schedules go to die.
New Detached ADU
A new detached ADU in Glendale typically runs $90,000 to $220,000 depending on size, site work, and whether the lot is in a Very High Fire Hazard Severity Zone. On hillside lots, the fire-hardening cladding, Class A roofing, and ember-resistant vents are not optional upgrades; they’re code-mandated. We order the long-lead items, like architectural glass and custom millwork, so they arrive when the rough-in is done, not six weeks after it. The price is fixed in writing before we order a single door.
Garage Conversion ADU
Converting an existing garage in Glendale costs $30,000 to $80,000, and the catch is usually what’s hiding behind the stucco. Many garages in Adams Hill and Grandview sit on original unreinforced foundations that predate modern seismic codes, so the slab work becomes its own line item. We write that every estimate, before demolition starts. Skipping it is how conversion budgets blow through their contingency in the first month.
Junior ADU & Interior Conversion
A Junior ADU inside an existing home is often the fastest path to a legal rental unit in Glendale, but the permit requirements still matter. Interior conversions don’t dodge the fire-sprinkler and egress reviews, and on a 1930s bungalow, the existing floor framing usually needs a closer look than the listing photos suggest. We’ll tell you the truth about what’s feasible before you spend money on drawings.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Glendale
We don’t stock mystery materials off the back of a van. For Glendale additions and ADUs, we install brands you can look up and price-check yourself, including Cambria quartz in kitchens and wet bars, KraftMaid cabinetry, Andersen and Marvin windows, and Belgard or Techo-Bloc pavers on exterior hardscape. If your designer specifies a particular architectural glass or specialty finish, we’ll bring it in and track the lead time on our schedule, not yours. Glendale homeowners get the same supplier relationships we’ve held for years, which means what’s ordered is what shows up.
Common Home Additions & ADU Problems We See in Glendale Homes
- Hillside lots priced like flat lots. A contractor quotes a 600-square-foot ADU in Chevy Chase Canyon using the same per-square-foot number he’d use in Burbank. Then the Chapter 7A fire-hardening cladding, retaining wall engineering, and slope-stability work eat the entire contingency before framing even starts. We price the actual lot, not a hypothetical one.
- Long-lead items ordered late. Custom architectural glass and custom millwork have real lead times, eight to sixteen weeks on some specialty orders. If those get ordered after the rough-in passes, the whole job sits idle and the owner thinks the crew is slow. We put long-lead items on the schedule at contract signing and write the delivery dates into the scope.
- Soils report skipped on an old cripple-wall foundation. Glendale’s clay-rich soils move seasonally, and a 1920s bungalow in Adams Hill sitting on an original wood cripple wall is already vulnerable. Skip the soils report, pour new footings, and you’ll be looking at cracks in the subfloor before the punch list is done. We order the geotech on any substantial addition, even in the flats.
- Designer-selected fixtures with no allowance on paper. The homeowner picks a $4,000 plumbing fixture suite and assumes it’s in the bid. It wasn’t. Now there’s a surprise invoice at the end, and the job finishes with bad blood. Every allowance, including tile and fixtures, goes in writing before we pull permits in Glendale.
Pricing for Home Additions & ADU in Glendale, CA
Here’s what you should expect to budget for a permitted project in Glendale. These are market ranges based on what our crews actually see in the field here, not national averages.
| Project Type | Typical Range in Glendale |
|---|---|
| Home Addition | $45,000 - $130,000 |
| ADU Construction | $90,000 - $220,000 |
| Garage Conversion | $30,000 - $80,000 |
The hillside premium in Glendale is real. A detached ADU on a graded lot in 91207 or 91208 will carry additional line items: geotechnical review, hillside grading, retaining wall work, Chapter 7A-compliant cladding and venting. That’s not a markup on our end; those are code-mandated assemblies that don’t exist on flat lots across the 134 Freeway. We put every one of them on the written scope before you sign, so the price you approve is the price you pay. Call (877) 610-1318 for a free estimate, and we’ll give you a line-item quote you can actually read.
We Also Serve Cities Near Glendale
Barrett & Sons Construction works throughout the communities surrounding Glendale, including Burbank, La Cañada Flintridge, Echo Park, and Silver Lake. Whether your project is a hillside ADU in the Verdugos or a room addition on a 1930s bungalow in the flats, the same crew and the same written-scope approach apply. One company, one standard, no surprises on the invoice.
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 - Home Additions & ADU in Glendale
Chapter 7A adds real money to a hillside ADU in Glendale because the code requires ignition-resistant cladding, ember-resistant vents, and Class A roofing on any substantial new construction inside the Very High Fire Hazard Severity Zone covering ZIPs 91207 and 91208. Depending on the product you choose, fire-hardening assemblies can add $15,000 to $40,000 on a detached ADU, plus a longer plan check while Building and Safety reviews the compliance details. The material is not optional, and the assembly details get inspected. Call (877) 610-1318 and we’ll show you exactly where those line items land in a written bid.
You can’t submit for permit with unselected materials, but you can lock in long-lead items like custom windows, architectural glass, and cabinetry once the drawings are approved and before the permit is pulled, so they’re on site when the rough-in passes. We do this on every Glendale ADU with custom finishes, and we write the delivery dates into the scope of work. It won’t shorten the city’s review time, but it keeps the construction calendar from stalling once we start.
Glendale’s clay-rich soils move with the seasons, and a 1920s Spanish bungalow on an original cripple-wall foundation is already responding to that movement. Any substantial addition triggers a geotechnical review because the new footings have to be engineered for the soil that actually exists under your house, not the soil from the original 1920s survey. Skipping it is how new subfloors end up cracked before the punch list clears. We order the geotech report as part of the permit package, not as an afterthought.
A Junior ADU in Glendale is an interior conversion within the existing footprint of the home, typically under 500 square feet, and usually has a faster permit path because there’s no new foundation and no separate utility connection. A detached ADU is a new structure, which means a full building permit, separate utility drops, and on hillside lots, the Chapter 7A and geotechnical reviews come into play. Interior JADUs still trigger fire-sprinkler and egress reviews, but they skip the foundation and slope-stability work entirely. We’ll tell you which one fits your lot and your budget before you pay for drawings.
Yes, we coordinate directly with your architect and designer on high-end Glendale additions, and we’ve done it on second-story projects in Montecito Park and custom ADUs in Verdugo Woodlands. We manage the submittals, track the long-lead finish schedule, and make sure the cabinetry, stone, and architectural glass arrive when the rough-in is signed off. You sign one contract, and we handle the sequencing. Call (877) 610-1318 for a free estimate, and we’ll walk you through how the whole schedule fits together.
Written by Tom Barrett, Owner at Barrett & Sons Construction. Tom founded the company in 1998 and still answers his own phone. Current jobs in Glendale include a detached ADU in Chevy Chase Canyon and a second-story addition in Montecito Park.