ADU in Long Beach, CA
Junior ADU & Interior Conversion in Long Beach typically runs $85,000-$145,000 all-in, drawings through final inspection, while ADU Site Prep & Utilities add $15,000-$55,000 depending on what the existing property needs. We’re Ellery ADU Studio, and we handle both under one contract at one written price - no designer-versus-builder blame gap. Call (562) 263-3350 to schedule your free estimate.
Long Beach’s independent building department and its dense stock of 1920s-1950s bungalows on alley-accessed lots create a unique ADU landscape. The city’s marine climate and salt-air exposure in coastal neighborhoods mean interior conversions and utility upgrades require specific material choices that inland contractors often miss. Our Los Angeles office coordinates dispatch and scheduling; crews serve Long Beach locally.
Why Long Beach Homes Are Different
Long Beach is a charter city with its own building department, separate from Los Angeles and LA County. That means plan check, permitting, fees, and inspections run through Long Beach’s own staff, with timelines and requirements that differ from neighboring cities. We’ve found their reviewers are thorough on fire separation and utility independence - especially for alley-facing conversions.
The housing stock splits the city. Central neighborhoods like Rose Park, Wrigley, and Bixby Knolls hold 1920s-1940s California Craftsman bungalows and Spanish Colonial Revival homes, many reconstructed after the 1933 Long Beach earthquake. These lots typically have detached single-car garages accessed from historic alleys. East Long Beach shifts to 1950s-1960s post-WWII ranch tracts with slab foundations and attached garages, requiring structurally different conversion approaches and often triggering fire-separation upgrades.
Climate matters too. Belmont Shore, Naples Island, and Bluff Park face persistent salt-air exposure that corrodes framing hardware, electrical panels, and plumbing fittings inside older detached garages. Problems often stay hidden until walls open. The marine climate reduces HVAC loads, but material specification for coastal corrosion resistance adds line items that inland ADU bids overlook.
Our Main Long Beach Services
Long Beach homeowners call us most often for these three services, each with its own dedicated Long Beach page:
ADU Design & Permitting in Long Beach
We produce the permit set as the core product, not an afterthought. For Long Beach’s independent building department, that means drawings calibrated to their specific checklists, from setback variances to alley-access utility independence. Our permit sets include structural, MEP, and Title 24 energy compliance in a single submission package. ADU Design & Permitting in Long Beach covers our full process.

Garage Conversion ADU in Long Beach
Alley-accessed garages in Rose Park and Wrigley convert with genuinely independent rear-entry access - a configuration Long Beach’s building department accommodates and one that commands higher rents because tenants never share an entrance with the primary dwelling. Slab conditions, fire separation, and utility routing vary block by block. Garage Conversion ADU in Long Beach details our approach.

New Detached ADU in Long Beach
When the existing structure won’t convert or when the lot has usable rear yard beyond the garage footprint, we design and build new detached units. Setback rules in Long Beach differ by zoning overlay, and the city’s alley grid sometimes allows rear-lot placement that maximizes privacy. Foundation type and utility trenching drive the preliminary budget. New Detached ADU in Long Beach explains our single-contract model.

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.
Junior ADU & Interior Conversion in Long Beach

Junior ADU & Interior Conversion in Long Beach solves the problem of aging, underutilized space inside existing homes and attached structures. The city’s 1920s-1950s housing stock offers prime candidates: basements in Belmont Heights, bonus rooms over garages in Bixby Knolls, and attached additions in East Long Beach ranch homes that can be reconfigured without touching the primary dwelling’s footprint. Junior ADU & Interior Conversion covers our full service scope nationwide.
Salt-air corrosion in coastal neighborhoods often reveals itself during interior demolition, and the city’s independent building department requires specific documentation for fire separation and utility metering when a JADU shares walls with the main house. We address both in the permit set before construction starts.
Room-to-ADU Conversion
Signs you need it
An attached bedroom, den, or former servant’s quarters sits unused while your mortgage payment climbs.
What it costs in Long Beach
Room-to-ADU conversions in Long Beach typically run $85,000-$125,000 all-in, including the permit set, fire-separation upgrades, and independent utility metering where required.
How we do it
We survey existing conditions, produce a permit set with fire-rated assemblies and utility routing, then build to that set under our single contract with a written price locked at signing per Haven Standard Clause 1.
Interior JADU
Signs you need it
You need rental income but the lot has no room for a detached unit, or the garage is already converted to workshop space.
What it costs in Long Beach
Interior JADUs in Long Beach typically run $75,000-$115,000 all-in, with costs at the lower end when existing bathrooms and kitchen plumbing can be tapped.
How we do it
We identify the smallest viable footprint inside the existing structure, design for owner-occupancy compliance, and coordinate Long Beach’s required exterior door or separate entrance modification.
What Junior ADU & Interior Conversion Costs in Long Beach
| Item | Typical range in Long Beach |
|---|---|
| Room-to-ADU conversion (all-in) | $85,000-$125,000 |
| Interior JADU (all-in) | $75,000-$115,000 |
| Above-garage ADU (all-in) | $95,000-$145,000 |
Does a Junior ADU need its own kitchen and bathroom in Long Beach?
Yes, Long Beach requires a kitchen with cooking facilities and a separate bathroom for JADU approval, though both may share walls with the primary dwelling’s systems. Call (562) 263-3350 for an exact quote - estimates are free.
Can I convert a basement in Belmont Heights to a Junior ADU?
Basement conversions are viable where ceiling height reaches 7 feet 6 inches and egress windows meet current code; many 1920s Belmont Heights basements need excavation or benching to qualify. Call (562) 263-3350 for an exact quote - estimates are free.
ADU Site Prep & Utilities in Long Beach

ADU Site Prep & Utilities in Long Beach addresses the hidden infrastructure that makes or breaks conversion and new-build timelines. The city’s aging utility networks, combined with salt-air degradation in coastal neighborhoods and slab-on-grade construction in East Long Beach, mean electrical panels, plumbing laterals, and gas lines often need upgrade before the ADU itself begins. ADU Site Prep & Utilities details our national scope.
We’ve opened walls in Bluff Park garages to find electrical panels corroded beyond serviceability, and we’ve trenched through East Long Beach ranch lots where original clay sewer laterals collapsed. These aren’t surprises we spring mid-project; they’re conditions we identify in preliminary survey and price into the written scope upfront.
Electrical Panel Upgrade
Signs you need it
The existing panel is rated below 200 amps, shows corrosion, or lacks physical space for ADU circuits.
What it costs in Long Beach
Electrical panel upgrades for ADU service in Long Beach typically run $4,500-$8,500, including permit, inspection, and SCE coordination.
How we do it
We load-calculate the ADU plus existing dwelling, specify the new panel and service lateral, and coordinate Southern California Edison for meter separation where required.
Plumbing Lateral
Signs you need it
Original clay or cast-iron sewer lines show root intrusion, belly sag, or corrosion when camera-inspected.
What it costs in Long Beach
Plumbing lateral replacement or trenchless relining in Long Beach typically runs $8,000-$18,000 depending on length, depth, and street-to-house access.
How we do it
We camera the existing line, produce a video record for the client, then specify open-cut or trenchless replacement based on depth and obstructions, with Long Beach Water Department coordination.
What ADU Site Prep & Utilities Costs in Long Beach
| Item | Typical range in Long Beach |
|---|---|
| Electrical panel upgrade | $4,500-$8,500 |
| Plumbing lateral replacement/relining | $8,000-$18,000 |
| Foundation and grading (new detached) | $15,000-$35,000 |
Will Site Prep delay my ADU timeline in Long Beach?
Site prep typically adds 2-4 weeks before construction starts, but identifying conditions early prevents the 6-10 week delays that hit projects where utilities fail mid-build. Call (562) 263-3350 for an exact quote - estimates are free.
Does Long Beach require separate utility meters for ADUs?
Junior ADUs may share meters with owner-occupancy documentation; detached ADUs and most garage conversions require independent electric and often water metering, which we coordinate with SCE and Long Beach Water during design. Call (562) 263-3350 for an exact quote - estimates are free.
Brands We Service in Long Beach
We specify and coordinate prefab and modular systems from Mighty Buildings, Boxabl, and Plant Prefab within our single-contract model, sourcing components through regional distributors with typical 4-6 week lead times. Our crews are fluent in Tuff Shed utility integration for hybrid builds. our brands
Pricing for ADU in Long Beach, CA

| Service | Typical range in Long Beach |
|---|---|
| Room-to-ADU conversion (all-in) | $85,000-$125,000 |
| Interior JADU (all-in) | $75,000-$115,000 |
| Above-garage ADU (all-in) | $95,000-$145,000 |
| Electrical panel upgrade | $4,500-$8,500 |
| Plumbing lateral replacement/relining | $8,000-$18,000 |
| Foundation and grading (new detached) | $15,000-$35,000 |
Prices push higher in Long Beach when salt-air corrosion requires material upgrades, when alley utility trenching encounters unexpected obstructions, or when fire-separation assemblies in attached conversions demand rated drywall and draft-stopping beyond standard scope. Every project is quoted with a written price before any work begins, per Haven Standard Clause 1 - no exceptions.
Neighborhoods We Serve in Long Beach
We work across Long Beach’s full residential map, from coastal corrosion zones to inland slab-on-grade tracts. Crews are staged for response throughout the metro area.
- Rose Park
- Wrigley
- Bixby Knolls
- Belmont Shore
- Bluff Park
Service Area - Cities Near Long Beach

Our crews serve homeowners throughout the Long Beach metro and adjacent communities, including Seal Beach, CA to the south, Lakewood, CA to the north, Los Alamitos, CA to the east, and Cypress, CA to the northeast. Each city maintains its own building department with distinct ADU requirements, and our permit sets are calibrated accordingly.
Serving Long Beach, CA - Our Local Coverage Area
We’re based in the Long Beach 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 Long Beach

Long Beach’s independent building department typically completes ADU plan check in 8-12 weeks for complete submittals, though expedited review is available for certain conversion types; incomplete packages cycle back with corrections that add 4-6 weeks.
California state law limits HOA prohibition of ADUs, but Long Beach HOAs may impose design guidelines on exterior appearance; we review CC&Rs during preliminary design to flag enforceable restrictions before permit submittal.
Yes, we regularly work in Belmont Shore and coastal Long Beach neighborhoods, specifying corrosion-resistant materials and elevated foundation details where salt-air exposure and flood-zone requirements apply.
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 Long Beach Customers Say
"They walked us through setbacks and utility capacity before we paid anything, and told us one of our two options was not going to get approved."
- Mireille T."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.