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 Beverly Hills
A Home Addition or ADU in Beverly Hills typically runs $45,000-$130,000 for a room addition and $90,000-$220,000 for a detached ADU, and the single biggest variable is whether your contractor knows Beverly Hills Building & Safety’s own plan-check queue, not LADBS. We’re Barrett & Sons Construction, and we’ve built additions and ADUs across the flats south of Santa Monica Boulevard and up into the 90210 hills long enough to know which inspections stall, which local amendments bite, and what a compliant quote actually includes. Call (877) 610-1318 and we’ll walk your lot with you, on paper, before anything gets filed.
Why Barrett & Sons Construction Is Beverly Hills’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998, and his sons run the crews. That matters in Beverly Hills because the city’s plan checkers know who files clean drawings and who files sloppy ones, and we’ve spent nearly three decades building the kind of file that gets through without correction cycles. When a Beverly Hills homeowner calls us about a Home Additions & ADU project, they get a live person on the phone, not a voicemail box. They get a written scope, written allowances, and written change orders before any work moves. And they get Tom’s name, address, and license number right on the estimate, because in this city, verifiable beats smooth talk.
Beverly Hills runs its own Building & Safety Division with local amendments to the California Building Code. A permit filed through LADBS gets rejected outright. We’ve sat through enough pre-application meetings with Beverly Hills plan checkers to know which shear wall details they flag, which hillside drainage drawings they want stamped, and which WUI cladding products they’ll sign off on without a fight. That’s not generic knowledge. That’s the difference between a project that starts when the loan closes and one that burns three months in corrections.
The 90-Day Done Right Promise is written on every contract we sign in Beverly Hills. If something isn’t done right, Tom comes back. One call. That’s it. And every eligible job here gets permits pulled and inspections signed, because the last contractor most of our Beverly Hills clients used told them permits were optional. Ask anyone on your street, or look up the license number yourself.
Our Home Additions & ADU Services in Beverly Hills
ADU Design & Permitting
Beverly Hills has its own ADU ordinance layered on top of state law, and the city’s plan-check queue runs at its own pace. We handle the full design and permitting package: site plans, structural drawings, Title 24 energy compliance, and the Beverly Hills-specific forms that LADBS wouldn’t know existed. For a detached ADU on a 90210 hillside lot, that package usually includes geotech review, WUI ignition-resistant cladding specs, and drainage calculations before we ever file. Our Beverly Hills clients get a pre-application meeting with Building & Safety whenever the scope warrants it, and we’ve learned exactly what to bring to that meeting so it doesn’t turn into two more correction cycles.
Garage Conversion ADU
A garage conversion in Beverly Hills runs $30,000-$80,000, and the flats south of Santa Monica Boulevard are full of 1920s Spanish Colonial Revival garages with original slab foundations that were never engineered for habitable space. We check the slab, the roof structure, and the panel before we quote, because a garage conversion ADU here often means a new 200-amp service and shear upgrades that a cheaper bid simply leaves out. Beverly Hills inspectors want to see the hold-downs, the strapping, and the insulation certificates. We plan for all three from day one.
New Detached ADU
New detached ADUs in Beverly Hills run $90,000-$220,000, and on hillside parcels in 90210 that number climbs fast once geotech and retaining walls enter the picture. Chapter 7A wildfire requirements apply across much of the hills, so your ADU gets Class A roofing assemblies, ember-resistant vents, and ignition-resistant cladding. We buy local, we stage deliveries around Beverly Hills’s street access restrictions, and we know which lots require a deputy inspector just to pour the foundation. The permit package is the hardest part of this job, which is exactly why we front-load it.
Junior ADU & Interior Conversion
A Junior ADU, often carved out of an existing bedroom or den, is usually the fastest path to legal rental income in Beverly Hills. These conversions range from modest kitchenette work to full plumbing rough-ins, and Beverly Hills will still want a separate occupancy permit even if the square footage is small. We’ve converted spare rooms in 90212 Tudor homes where the original cast-iron supply lines needed replacing and the panel was already maxed. We handle the plumbing, the electrical, the egress, and the paperwork as one scope, with one 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 Beverly Hills
We install Simonton and Ply Gem windows on our Beverly Hills additions and ADUs because both brands meet California’s Title 24 energy requirements and carry the impact ratings that matter when a hillside inspector asks for documentation. We also stock parts and hardware locally so warranty work and adjustments don’t wait on a truck from out of state. If a Ply Gem sash fails on a sunroom we built off Benedict Canyon, we’ll be there with the replacement, not a phone number for a manufacturer’s call center.
Common Home Additions & ADU Problems We See in Beverly Hills Homes
- Filing through LADBS by mistake. Beverly Hills is its own municipality, and an application sent to LA City’s system gets bounced. That single error can add weeks to a project where carrying costs on a construction loan in Beverly Hills run tens of thousands per month.
- Skipping the pre-application meeting. Plan checkers in Beverly Hills issue correction cycles for local amendments: shear wall details, hillside drainage, WUI cladding. A cheap quote never accounts for these, and the homeowner pays for it later as a change order.
- Outsiders treating the inspection queue like LA’s. Draw schedules stall at the inspection sign-off line item when a contractor doesn’t know Beverly Hills’s inspector assignments. Punch-list timing slips, and the client ends up paying change orders to fix non-compliant rough-in.
- Undersized panels and old galvanized pipe on 1920s flats stock. South of Santa Monica Boulevard, we routinely open walls on original lath-and-plaster and find 60-amp panels and galvanized supply lines that were never meant to carry an ADU’s electrical load. We plan for these upgrades in the initial scope, not as a surprise.
Pricing for Home Additions & ADU in Beverly Hills, CA
Here’s what Beverly Hills homeowners should budget, based on what we’ve built in this market. Room additions run $45,000-$130,000 depending on square footage, foundation work, and whether you’re in the flats or on a hillside. Detached ADUs run $90,000-$220,000. Garage conversions run $30,000-$80,000. These are written, line-itemed numbers, not phone estimations. The hills and the flats price differently, and we’ll show you exactly why on paper.
| Home Addition | $45,000-$130,000 |
|---|---|
| ADU Construction | $90,000-$220,000 |
| Garage Conversion | $30,000-$80,000 |
| Second Story Addition (as part of Home Addition scope) | Included in Home Addition pricing above |
Every estimate we give in Beverly Hills is free, and it comes with a written line-item scope, written allowances, and a written change order policy before anything moves. Call (877) 610-1318 to schedule yours.
We Also Serve Cities Near Beverly Hills
We work across the surrounding area, so if your project sits just outside the Beverly Hills city line, we can still help. We regularly serve Beverly Hills residents, plus homeowners in Century City, West Hollywood, Culver City, and Hollywood. Same crews, same written change orders, same 90-Day Done Right Promise.
Serving Beverly Hills, CA - Our Local Coverage Area
We’re based in the Beverly 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 Beverly Hills
Yes. Beverly Hills enforces its own local amendments to the California Building Code, and second-story additions in the 90210 hills typically require geotechnical reports, engineered shear wall details, and drainage plans that LA City’s code wouldn’t demand. Plus, most of the hills sit in the Wildland-Urban Interface, so CAL FIRE Chapter 7A requirements for ignition-resistant cladding and ember-resistant vents apply. We bring a pre-application meeting with Beverly Hills Building & Safety into the plan early so those extra requirements are priced in before the first inspection. Call (877) 610-1318 and we’ll walk your specific lot with you.
Beverly Hills plan check for a detached ADU typically runs 8-16 weeks, depending on complexity, while LADBS often moves on a similar or slightly faster timeline. The critical difference isn’t speed; it’s that an application filed through LADBS for a Beverly Hills property gets rejected immediately. Filing through the correct Beverly Hills system, with the correct local amendment documentation, is what keeps a project on schedule. We track our Beverly Hills permits weekly and call the plan checker directly when something stalls, which is something a contractor from outside the city simply can’t do. Call (877) 610-1318 if you’re trying to budget timeline along with cost.
Yes, and this is one of the most important reasons to never let a contractor talk you out of pulling permits. A Beverly Hills ADU with a signed final inspection from the city’s Building & Safety Division gives your insurer documented proof that the structure was built to code. After a fire or a liability claim, an unpermitted ADU becomes a reason for denial or premium increases, while a permitted one with documentation stands. We keep a full permit file and inspection record for every Beverly Hills completion and hand copies to the homeowner for their insurance file. Call (877) 610-1318 to discuss your specific insurance situation.
The change order arrives in writing, with a line-itemed price, before that pipe gets touched. On the flats south of Santa Monica Boulevard, homes from the 1920s and 1930s frequently have original cast-iron drainage and galvanized supply lines that only reveal themselves once we open the wall. We don’t surprise you at the end. We stop, show you what we found, write the scope change on paper, and get your signature before the work proceeds. That’s how we’ve done it for 29 years, and it’s exactly what the national outfits don’t do. Call (877) 610-1318 if you want a contractor who puts surprises on paper first.
In most cases, yes. Beverly Hills requires permits for sunrooms and enclosed patios regardless of size because they modify the building envelope and affect egress, electrical, and possibly structural connections. Even a small sunroom changes your heat-load calculations and triggers Title 24 energy compliance. We handle the permit package for sunrooms and enclosed patios in Beverly Hills as part of the standard scope, so the work is legal and documented from day one. Call (877) 610-1318 and we’ll tell you exactly what your sunroom needs before we quote it.
Get Your Beverly Hills Home Addition or ADU Started Today
On a 1920s Spanish Colonial Revival in the flats south of Santa Monica Boulevard, our crew opened a load-bearing wall for a kitchen-to-family-room addition and found the original lath-and-plaster over undersized galvanized supply lines and a 60-amp panel. We pulled Beverly Hills permits, upgraded the subfloor with code-required shear nailing and hold-downs, ran a new 200-amp service and rough-in plumbing before drywall, and kept a punch list with the city inspector until sign-off, all documented for the homeowner’s insurance file. That’s how we build in Beverly Hills.
Beverly Hills is an independent municipality entirely surrounded by Los Angeles, with its own Building & Safety Division, not LADBS. Residential lots here routinely value at $5M-$30M and up, and the client base demands custom luxury finishes and white-glove project management. Virtually every construction engagement in Beverly Hills operates at a scope and compliance burden that prices out contractors who only work in surrounding LA neighborhoods. We work here, we know the queue, and we stand behind what we build with a 90-Day Done Right Promise in writing.
Call Tom and the team at (877) 610-1318 to schedule your free estimate. We’ll walk your Beverly Hills lot, tell you what’s possible and what it costs, and put every number on paper before you commit to anything. Free second opinion on any written estimate, no trip charge inside the county, and a permanent 10% senior and veteran discount.
Written by Tom Barrett, Owner at Barrett & Sons Construction, building in Beverly Hills since the company’s founding in 1998.