Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Before
After
Before
After
Before
AfterFast, Reliable Home Additions & ADU Across Valley Glen
A home addition or ADU in Valley Glen typically runs $45,000 to $130,000, with detached ADUs falling between $90,000 and $220,000 depending on size and site work. We’re Barrett & Sons Construction, owner-operated by Tom Barrett since 1998, and we know exactly what opening up a 1950s Valley Glen ranch or a 1960s tuck-under apartment building turns up. Before you sign anything, call (877) 610-1318 and we’ll walk you through what your specific lot in 91404 will actually require.
Valley Glen homes have a particular history, and that history shows up the moment a wall comes down or a foundation gets probed. We’re not a franchise dispatching strangers. Tom’s sons run the crews, and every price change arrives in writing before a single nail moves.
Why Barrett & Sons Construction Is Valley Glen’s Preferred Home Additions & ADU Company
We’ve spent years working on the post-WWII tract homes and mid-century apartment buildings that define Valley Glen’s streets. Homeowners between 50 and 70 keep calling us because they’ve already been burned by a contractor who quoted one price and delivered another. Our answer is simple: every scope, every allowance, every price change comes as a written change order before work happens. An allowance that isn’t on paper is a surprise waiting for a date.
Tom Barrett publishes his name, his address, and his license number. Look us up before you sign anything, and while you’re at it, ask anyone on your block. A live person answers our phone 24 hours a day, seven days a week. Not a voicemail box, not an out-of-state call center. When you call about a room addition or ADU in Valley Glen, you talk to someone who knows what the LA City Department of Building and Safety will flag on your property.
We pull permits and get inspections signed on every eligible job. The permit inspector works for you, not for me, and that’s exactly why we like him on site. Our Home Additions & ADU team brings the same owner-operated standard to every project in Valley Glen, from a second-story addition near Valley College to a detached ADU off Oxnard Street.
Our Home Additions & ADU Services in Valley Glen
ADU Design & Permitting
Valley Glen sits about five miles from the 1994 Northridge earthquake epicenter. That means any ADU design here has to account for the neighborhood’s seismic retrofit triggers before the first drawing gets stamped. We handle the full design and permitting path, including the LA City checks that catch soft-story buildings under Ordinance 183893 and the structural upgrade requirements that come with opening load-bearing walls on older homes.
Garage Conversion ADU
A garage conversion in Valley Glen typically runs $30,000 to $80,000. Many of the detached garages in this ZIP were built in the late 1940s and 1950s with slab foundations that have shifted in the Valley’s expansive clay. Before we convert, we check what the foundation is actually doing and whether your garage sits in a tuck-under configuration that triggers soft-story retrofit review.
New Detached ADU
A new detached ADU in Valley Glen runs $90,000 to $220,000. The wide range comes down to soil movement. Valley Glen’s clay expands and contracts with rain and drought, so compacted soils that shed water quickly can change how much support work your ADU foundation needs. We include site prep, utilities trenching, drainage, and seismic tie-downs in the written scope, not as surprises on the back end.
Junior ADU & Interior Conversion
Junior ADUs, typically 500 square feet or less, are a practical option for Valley Glen ranch homes with an oversized attached garage or a rarely used den. Since these projects convert existing interior space, the discovery work is different from a new build. We still plan for what’s behind the walls, because a 1948 tract home rarely gives up its framing without showing its age.
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 Valley Glen
When a Valley Glen project calls for new windows, doors, or glazing, we carry brands you can look up rather than mystery stock off a van. Simonton and Ply Gem windows hold up to the San Fernando Valley’s extreme summer heat, where thermal cycling stresses exterior caulking and framing joints far more aggressively than on the Westside. PGT impact-rated products come into play on Valley Glen properties where the owner wants the seismic and security benefit in one install. We stock parts for these lines locally for Valley Glen customers, which shortens lead times when a second-story addition or ADU rough-in needs to stay on schedule.
Common Home Additions & ADU Problems We See in Valley Glen Homes
- Northridge-era structural fatigue: Many ranch homes and apartment buildings in Valley Glen got hasty post-quake repairs in the mid-1990s that are now aging out. A room addition that starts as a simple bump-out can turn into a shear-wall and foundation upgrade once we expose what’s underneath.
- Hidden moisture behind original stucco: The 1960s ramblers along Valley Glen’s residential streets often hide rot behind the original brown coat. When a sunroom addition ties into an existing exterior wall, that moisture has to be remediated before framing can proceed.
- Expansive clay shifting slabs: Valley Glen’s soil expands and contracts dramatically with the Valley’s wet-dry cycles. We’ve measured differential settlement over an inch on post-WWII slab foundations, which directly affects whether a second-story addition is feasible without underpinning.
- Obsolete wiring discovered mid-remodel: Opening a wall on a 1948 tract home frequently reveals original knob-and-tube or undersized panels that won’t pass current code once new square footage is added. We write the electrical upgrade into a change order before cutting further, so the job doesn’t stall.
Pricing for Home Additions & ADU in Valley Glen, CA
Here are the numbers we quote for Valley Glen work, based on the market we’ve actually built in:
| Project Type | Typical Valley Glen Range |
|---|---|
| Home Addition | $45,000-$130,000 |
| ADU Construction | $90,000-$220,000 |
| Garage Conversion | $30,000-$80,000 |
What moves the number on a Valley Glen project more than anything is what we find once walls are open. Foundation settlement on expansive clay, failed shear transfer from the quake, rotted framing behind original stucco, outdated wiring. These aren’t surprises to us, and they shouldn’t be surprises to you. Our fixed-price approach means the original scope is in writing, and any discovery gets priced and approved by you before we touch it. That’s the difference between a quote and an actual plan. Call (877) 610-1318 for a free estimate and we’ll put your Valley Glen project’s real numbers in writing.
We Also Serve Cities Near Valley Glen
Barrett & Sons Construction serves homeowners throughout the central San Fernando Valley. If you’re in Home Additions & ADU in Valley Glen, Van Nuys, Sherman Oaks, Encino, or North Hills, you’re in our service area. We know the building departments, the soil conditions, and the housing stock in each of these neighborhoods, so the estimate you get reflects the city where your house actually stands.
Serving Valley Glen, CA - Our Local Coverage Area
We’re based in the Valley Glen 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 Valley Glen
Yes, it can. If your Valley Glen property has a two-story tuck-under garage configuration, LA City Ordinance 183893 may require a soft-story retrofit before or as part of your ADU approval, depending on the building’s current compliance status and the scope of structural changes. We check your property’s retrofit status during the feasibility phase so you know whether the ADU path includes structural work on the existing building. Call (877) 610-1318 and we’ll look up your address.
Expect the permitting path to require electrical upgrades, shear-wall improvements, and possibly foundation work once load-bearing walls are opened on a 1950s Valley Glen ranch. The original knob-and-tube wiring and undersized framing common in this housing stock won’t pass current code when new square footage is added, and the city will require those items be addressed before sign-off. We write those allowances into the contract upfront so you aren’t handed a surprise invoice at the end.
Valley Glen’s clay soil swells when wet and shrinks when dry, which causes differential movement across slab foundations over decades. For a room addition or detached ADU, this means the foundation design has to account for that movement, often requiring deeper footings, steel reinforcement, or special grading. A foundation that ignores the clay will crack within a few wet seasons. We factor the soil into every Valley Glen estimate before we ever break ground.
Usually, yes, but only if the existing roof structure is sound and meets current code for the new occupancy. Many Valley Glen detached garages have flat or low-slope roofs that pool water, and if the roof framing has sagged or the membrane has failed, the city will require roof work before signing off on the conversion. We’ll tell you straight after inspection whether your garage roof can stay or needs replacement, and write that cost into the proposal before you decide.
Often yes, but it depends on the existing foundation, framing, and shear capacity. Many 1950s Valley Glen ranch homes were built with slab foundations and 2×4 framing that need reinforcement before supporting a second story. We assess the structure first, then give you a written answer on what the addition requires. If the numbers don’t make sense, we’ll tell you that too. Call (877) 610-1318 for a free evaluation.
If you’re planning a Home Additions & ADU project in Valley Glen, call Barrett & Sons Construction at (877) 610-1318. We’ll give you a free estimate with every scope and allowance in writing, permits pulled and inspections signed, and a 90-Day Done Right Promise on the finished work.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Valley Glen since 1998.