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 North Hills
A home addition or ADU in North Hills runs between $45,000 and $130,000 for most projects, with a full detached ADU landing closer to $90,000-$220,000 depending on site conditions and finishes. We serve North Hills from the San Fernando Valley side of Los Angeles, and our crews know the difference between a clean 1960s tract home and one that’s been quietly hiding post-1994 earthquake patches behind fresh drywall. If you’re weighing a garage conversion, a second story, or a backyard ADU in the 91343 or 91393 ZIP codes, we’ll walk you through the numbers first and never start a job without permits pulled. Call (877) 610-1318 to schedule a free estimate.
Key Takeaways:
- Home additions in North Hills typically cost $45,000-$130,000; garages conversions run $30,000-$80,000.
- Every project includes permits pulled and inspections signed, plus the written 90-Day Done Right Promise.
- North Hills’s post-1994 earthquake patch history means we inspect structural work other contractors skip.
- You’ll get written change orders before any scope change costs you a dime.
Why Barrett & Sons Construction Is North Hills’s Preferred Home Additions & ADU Company
Tom Barrett founded Barrett & Sons Construction in 1998, and 29 years later, his sons run the crews. When you call about an ADU or addition in North Hills, you’re not getting a national outfit that dispatches strangers. You’re getting a family-owned operation where Tom’s name, address, and license number are published and easy to verify before you sign anything.
North Hills homeowners call us because our Home Additions & ADU work holds up to the Valley’s specific demands. We’ve worked on post-WWII tract homes off Sepulveda Boulevard, on streets bordering Northridge and Van Nuys, and on the older apartment-lined corridors where L.A.’s soft-story retrofit rules apply. Our crews arrive in uniform, background-checked, and answer to Tom. A live person picks up the phone 24/7, not a voicemail box, not an out-of-state call center.
We carry premium brands across every trade, so a sunroom or second-story addition in North Hills gets materials you can look up: Simonton windows on the framing, GAF roofing overhead, and the same scrutiny on the foundation as on the finish work. That’s the difference between a contractor who lives twenty minutes away and one who hopes you never call again after the final check clears.
Our Home Additions & ADU Services in North Hills
ADU Design & Permitting
Building an ADU in North Hills means navigating City of Los Angeles planning requirements, which have shifted repeatedly since the state ADU mandates kicked in. We handle the full design and permit package so you don’t spend months chasing corrections. Whether it’s a detached unit behind a home near Devonshire Street or an interior conversion off Sepulveda, we submit plans, pull permits, and get inspections signed before you ever see a change order.
Garage Conversion ADU
North Hills is full of single-family homes with attached garages from the 1950s and 1960s, and many were built on slabs that are now cracking from decades of Valley heat cycling. A garage conversion here runs $30,000-$80,000 and requires a careful look at the slab, the perimeter walls, and any soft-story conditions if the garage sits under living space. We don’t mask problems with drywall; we correct them so the inspector signs off and the unit actually holds value.
New Detached ADU
A new detached ADU in North Hills runs $90,000-$220,000 depending on square footage, site access, and whether you need trenching for utilities across a long backyard. North Hills’s compact lots, especially east of the 405, often mean tight setbacks and tricky utility runs. We plan for that from day one, and we coordinate with LADWP for service upgrades so you’re not paying for surprises at the electrical panel.
Junior ADU & Interior Conversion
A Junior ADU, typically 500 square feet or less, is the most affordable path to rental income or a multigenerational setup in North Hills. We convert existing bedrooms, dens, or attached spaces into code-compliant units with separate entries, efficiency kitchens, and dedicated HVAC zones. On homes that went through 1994-era patch repairs, we probe those surfaces before framing begins, because a JADU inside a structure with unresolved earthquake damage is not something any inspector in L.A. will sign off on.
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 North Hills
For additions and ADU projects in North Hills, we install materials that stand up to Valley heat and Santa Ana winds. That’s Simonton windows on room additions, PGT impact-rated options where code or owner preference calls for it, and Ply Gem trim packages that survive the dry inland climate better than cheap alternatives. We keep local parts availability in mind, because a window or trim delay on an open-framing job in the middle of a North Hills heat wave isn’t a weather inconvenience, it’s a scheduling and materials problem. If you’re also considering a kitchen or Bathroom Remodeling in North Hills as part of your addition, our crews can sequence both trades under one permit set and one 90-Day Done Right Promise.
Common Home Additions & ADU Problems We See in North Hills Homes
- Post-1994 earthquake surface patches: Homes across North Hills carry cosmetic fixes over cracked mudsills, sheared cripple walls, or displaced anchor bolts that were never structurally corrected after the Northridge quake. Any addition that ties into the existing structure forces us to open those areas, because the permit inspector works for you, not for us.
- Slab heaving from Valley heat and soil movement: The eastern San Fernando Valley’s expansive soils move through wet-dry cycles, and North Hills’s post-WWII slab foundations show it. A room addition or garage conversion on a compromised slab needs soil and structural evaluation before the first stake goes in, otherwise cracks return within two seasons.
- Soft-story apartment building constraints: The 1960s-1970s two- and three-story apartment corridors off major streets in North Hills fall under L.A.’s mandatory soft-story retrofit ordinance. If you own one of those buildings and want to add an ADU to the lot, we sequence the retrofit work with the new construction so you’re not paying twice for mobilization and permits.
- Santa Ana wind and debris containment: Fall Santa Ana events hit North Hills with gusts that turn open framing into a debris liability. Our crews schedule major framing and roofing phases around those winds, and we tarp and contain as a matter of daily habit, not after a complaint from a neighbor on Langdon Avenue.
Pricing for Home Additions & ADU in North Hills, CA
A room addition or second-story addition in North Hills runs $45,000-$130,000. Garage conversions land at $30,000-$80,000, and a new detached ADU typically starts around $90,000 and can reach $220,000 for a larger unit with full utilities and premium finishes. What moves the price is structural repair from old earthquake damage, slab condition, utility trenching distance, and whether the site sits on one of the Valley’s expansive soil zones that requires deeper footings or helical piers.
We give you a written, line-item estimate before work starts, and every scope or allowance change arrives as a written change order before any new cost touches the job. No surprise invoices; the allowance that isn’t on paper is a surprise waiting for a date. Call (877) 610-1318 for an exact quote on your North Hills project, estimates are free, and there’s no trip charge inside the county.
We Also Serve Cities Near North Hills
Our crews regularly work in North Hills and the surrounding San Fernando Valley communities, including Northridge, Van Nuys, Valley Glen, and San Fernando. If you’re a few blocks outside the city line, call anyway. We schedule locally and the no-trip-charge policy applies inside the county. You’ll also find us handling Kitchen Remodeling in North Hills and other trades across those same neighborhoods.
Serving North Hills, CA - Our Local Coverage Area
We’re based in the North Hills 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 North Hills
We schedule North Hills work within a normal planning window, not an emergency-dispatch model, because additions and ADUs require permits, engineering, and sequencing. What we can promise is a live person on the phone when you call (877) 610-1318, and an estimate visit without a trip charge inside the county. From there, we’ll give you a written schedule in the estimate, and we stick to it.
Yes, we cover the entire North Hills area, including the 91343 and 91393 ZIP codes, from the residential streets west of the 405 to the commercial corridors along Sepulveda and Nordhoff. We’re familiar with the tract-home subdivisions and the older apartment-lined streets, and we don’t treat North Hills as a distant corner of a larger service map.
Yes. Given how close North Hills sits to the 1994 Northridge epicenter, we routinely address soft-story conditions, cracked slabs, sheared cripple walls, and displaced anchor bolts as part of addition and ADU projects. We won’t frame over a structural problem, and we won’t hide one behind stucco. If your existing home needs retrofit work before an addition can pass inspection, we’ll put it in writing as a separate line item, not a surprise mid-project.
For home additions, expect $45,000-$130,000 in North Hills, which is consistent with the rest of the eastern San Fernando Valley. What changes the price is the age and condition of the existing structure, site access, and soil conditions, not which specific Valley city you call. North Hills’s slab-on-grade tract homes sometimes need more foundation work than newer construction elsewhere, and we account for that in the line-item estimate, not as an after-the-fact upcharge.
Every project gets our written 90-Day Done Right Promise: if it’s not done right, Tom comes back and makes it right, one call. That’s on top of manufacturer warranties on the materials we install, from Simonton windows to GAF roofing. If something shifts or fails within that window, we’re twenty minutes away, and we want to know about it.
Schedule Your Free Estimate in North Hills
If you’re planning a home addition, garage conversion, or ADU in North Hills, call Barrett & Sons Construction at (877) 610-1318. Tom and his sons will walk your lot, look at what’s really there under the drywall and behind the stucco, and give you a written estimate with permits, allowances, and scope all spelled out. No pressure, no mystery pricing. Just a contractor whose name is on the truck and who answers his own phone.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving North Hills since 1998.