How Much Does Garage Conversion ADU Cost in Long Beach?
Our Garage Conversion ADU services in Long Beach, CA typically cost $95,000 to $210,000 all-in – drawings, permits, and construction under one contract. Most single-car garage conversions land between $95,000 and $140,000; two-car garages converted to a full one-bedroom unit generally run $145,000 to $210,000, depending on the condition of the existing structure, utility hookup complexity, and finish level. Every project Ellery ADU Studio quotes includes a written price before any work begins, per Haven Standard Clause 1 – so the number you see on your proposal is the number on your final invoice.
Garage Conversion ADU Cost Breakdown (2026)
Below is how the budget typically distributes across a Long Beach garage conversion. These ranges reflect real project costs in Long Beach’s coastal and inland neighborhoods – Belmont Shore, Wrigley, Bixby Knolls, Signal Hill adjacents, and the east side – not regional averages pulled from statewide data.
| Line Item | Typical Range | Notes |
|---|---|---|
| Architectural drawings & permit set | $8,000 – $18,000 | Includes site plan, floor plans, Title 24 energy calcs, structural details. Ellery treats this as the core product – not a loss-leader hand-off. |
| Long Beach building permit fees | $4,500 – $9,500 | City plan check, building, mechanical, electrical, and plumbing permit fees. Long Beach charges plan check at roughly 65% of the permit fee; budget for both in the first draw. |
| Foundation work | $3,500 – $22,000 | Most LB garages have 3.5- to 4-inch slabs. Habitable space requires a minimum 4-inch slab with a proper vapor barrier; slab thickening or a new perimeter stem wall adds cost. |
| Framing & structural | $8,000 – $24,000 | Garage-door opening infill, new interior partition walls, header upgrades, shear wall requirements per LBMC seismic zone. |
| Roofing & weatherproofing | $4,000 – $14,000 | If the existing roof is within five years of its service life, the permit inspector will flag it. Coastal Long Beach garages near the Marina and Naples see accelerated salt-air corrosion on flashing and fasteners. |
| Electrical (panel upgrade + ADU circuits) | $6,500 – $18,000 | Many Bixby Knolls and Wrigley homes still run 100-amp service. Adding an ADU almost always triggers a 200-amp upgrade – plan for it upfront. |
| Plumbing (kitchen + bath rough-in) | $9,000 – $22,000 | Distance from main sewer line matters most. A detached garage at the rear of a deep lot on the east side can mean 40-plus feet of new drain line, adding $4,000-$7,000 to this line item alone. |
| HVAC (mini-split system) | $4,500 – $9,000 | A single-zone Mitsubishi or Daikin mini-split is standard for a garage conversion. Long Beach’s mild climate keeps this cost predictable. |
| Insulation & drywall | $5,500 – $12,000 | Title 24 compliance for a coastal California climate zone (LB sits in CEC Climate Zone 8) sets specific R-values for walls and ceiling. Spray foam is sometimes required at the roof deck. |
| Windows & exterior doors | $4,000 – $10,000 | Egress windows are required in sleeping areas; Long Beach requires dual-pane glazing per current energy code. |
| Kitchen & bath finishes | $14,000 – $38,000 | Wide range driven by cabinet grade, fixture selection, and tile. A functional rental-grade finish runs $14,000-$20,000; a Belmont Shore owner-occupant unit with quartz and integrated appliances runs $28,000-$38,000. |
| Flooring | $3,500 – $9,000 | LVP over a new concrete topping slab is the most common spec for moisture management. Engineered hardwood adds cost and requires a floated subfloor. |
| Site work & utility connections | $5,000 – $18,000 | Separate water meter, gas line extension, or solar-ready conduit if required. Southern California Gas and SoCalGas service line extensions vary by lot depth. |
| Soft costs (soils, survey, Title 24) | $2,500 – $6,500 | Not every project needs a soils report, but Long Beach coastal lots – particularly in Naples Island and Belmont Shore – sometimes require one when foundation work is in scope. |
What the Total Typically Looks Like
Add those line items up and a Attached Garage Conversion for a single-car garage (220-350 sq ft) all-in lands at $95,000-$140,000. A two-car garage conversion (400-550 sq ft) producing a proper one-bedroom or studio with a full kitchen and bath runs $145,000-$210,000. Projects on the lower end of each range share a few traits: the slab is in good shape, the electrical panel is already 200 amps, the garage sits close to the main sewer clean-out, and the owners choose a clean functional finish rather than a luxury one.
Projects at the top end usually involve older Craftsman-era stock in Wrigley or Cal Heights, where the garage was built in the 1940s or 1950s, the foundation needs significant work, the electrical service requires a full upgrade, and the owners want finishes consistent with the quality of the main house. Neither outcome is a surprise when you have a written scope before demolition begins. That is the entire point of Haven Standard Clause 1.
What Affects Garage Conversion ADU Pricing in Long Beach
- Existing slab condition and thickness. Long Beach building code requires a minimum 4-inch concrete slab with a moisture barrier under any habitable floor. Garages built before 1975 – common in Wrigley, Rose Park, and the west side – frequently have 3- to 3.5-inch slabs poured without a vapor barrier. Slab thickening or replacement can add $8,000-$15,000 to a project and is one of the most common budget surprises we uncover on a pre-design site visit.
- Electrical service capacity. California requires ADUs to meet current energy code, and Long Beach’s building department enforces this at permit inspection. Homes with 100-amp main service – still common on 1950s and 1960s blocks in the Poly High area and east Long Beach – almost always need a panel upgrade to 200 amps before a new ADU sub-panel can be added. Budget $6,000-$10,000 for the upgrade alone, separate from ADU circuits.
- Distance from the main sewer and water lines. A garage at the back of a 140-foot lot in Bixby Knolls or North Long Beach means a long plumbing run. Every additional 10 feet of drain line adds roughly $800-$1,200 in materials and labor. This single factor can swing plumbing costs by $5,000-$8,000 on otherwise identical projects.
- Setback compliance and lot configuration. Long Beach’s ADU ordinance generally requires a minimum 4-foot side and rear setback for converted garages. Some alley-loaded lots in the Willmore City and 4th Street corridor neighborhoods sit close to those limits, requiring a survey and occasionally a setback variance – the formal city approval to build closer to a property line than the standard rule allows. Variance applications add $2,500-$5,000 and 6-10 weeks to the timeline.
- Coastal zone and historic district overlay. Properties within Long Beach’s coastal development permit area (generally west of Redondo Avenue south of Willow, plus the entire Belmont Shore and Naples peninsula) may require a separate Coastal Development Permit from the California Coastal Commission. That process adds $3,000-$8,000 in application costs and 3-6 months to the permit timeline – a fact most online ADU cost calculators do not mention.
- Finish level and fixture grade. The kitchen and bath line items are the most flexible in the budget. A builder-grade finish – solid-surface counters, stock cabinets, LVP flooring, and mid-line fixtures – produces a perfectly rentable unit for $14,000-$20,000 in finishes. An owner-occupant upgrading for a family member in Belmont Shore or Park Estates might spend $32,000-$38,000 on the same square footage with custom cabinetry, engineered stone, and integrated appliances. Both are valid choices; the difference belongs in the written scope from day one.
Before
AfterLong Beach ADU Permit Process: What You Are Actually Buying
At Ellery ADU Studio, we describe the permit set as the core product – not a bureaucratic hurdle we hand off to the city while construction waits. In Long Beach, a garage conversion permit typically moves through these stages: pre-application meeting (optional but often worth the 30 days it saves later), plan submittal to the Long Beach Development Services Department, plan check corrections (usually one or two rounds for ADUs), permit issuance, and then five to seven field inspections during construction: foundation, framing, rough mechanical-electrical-plumbing, insulation, drywall, and final. Every Ellery permit set is drawn to answer the plan checker’s likely questions before they ask them – reducing correction cycles and keeping your project on a predictable timeline.
Current plan check times at Long Beach Development Services for ADU projects, as of early 2026, run approximately 6-10 weeks for a standard over-the-counter submittal. Projects in the coastal zone or requiring a variance add time. We tell every client this at the proposal stage, in writing, so the construction start date is calibrated to reality rather than optimism.
How to Save on Garage Conversion ADU in Long Beach
Start with an honest pre-design assessment
The single biggest source of cost overruns in garage conversions is discovery – finding out during demolition that the slab is too thin, the panel is undersized, or the drain line is in the wrong place. Ellery’s pre-design site visit puts eyes on all three before the drawings start. That site visit produces a documented photo record, not a verbal summary. You get evidence of what we found – slab thickness, panel capacity, plumbing access – and that evidence drives the written scope. Fixing a surprise on paper costs nothing. Fixing it mid-construction costs $8,000 and three weeks.
Don’t over-specify the finish
If the unit will be a long-term rental in a North Long Beach or Wrigley neighborhood where comparable rents run $1,600-$2,100 per month for a studio or one-bedroom, a $38,000 kitchen finish does not pencil. A well-specified builder-grade finish at $15,000-$18,000 produces a unit that photographs well, rents quickly, and holds up to tenant use. Save the premium finishes for an owner-occupant unit where a family member will live long-term – and even then, put a ceiling on the kitchen and bath budget before design begins.
Combine your utility work
If you are already pulling a permit for plumbing and electrical, adding a gas line extension or a solar-ready conduit at the same time costs a fraction of what it would cost as a separate mobilization later. This is a standard conversation in every Ellery pre-design meeting: what other work is deferred on this property, and does it make sense to fold it into this permit set?
Know your Long Beach ADU fee waivers
California law (Government Code Section 65852.2) limits certain impact fees on ADUs under 750 square feet. Most garage conversions qualify. Long Beach has also historically waived school impact fees for ADUs meeting the size threshold. These are not negotiable discounts – they are statutory rights. An experienced design-build team builds them into the permit fee estimate automatically; a less experienced team quotes fees without them and calls the savings a “win” later.
Use the free second opinion
If you already have a written estimate from another contractor or design firm, Ellery offers a free second opinion on it. We read the scope line by line, flag what is included, what is missing, and where the number is likely to move during construction. This is not a sales call – it is a document review. Call (562) 414-4842 to schedule one.
Get the written price before any work starts
This sounds obvious, but most ADU cost overruns trace back to a contract that said “allowances” instead of prices and “scope to be determined” instead of line items. Haven Standard Clause 1 requires a written price on every Ellery project before the first drawing is started. No exceptions. If a contractor cannot give you a written price before work begins, that is not a negotiating position – it is a risk transfer onto you.
For a free estimate with a written price on your specific Long Beach property, call (562) 414-4842. A live person answers – no voicemail queue.
Garage Conversion ADU vs. New Detached ADU: The Cost Comparison
Homeowners in Long Beach who have the lot space sometimes ask whether converting the garage is actually cheaper than building a new Detached Garage Conversion from scratch. The honest answer: usually yes, but the gap is smaller than most people expect, and sometimes it disappears entirely.
A new detached ADU in Long Beach – 400 to 500 square feet, slab-on-grade, simple rectangular footprint – typically costs $175,000 to $285,000 all-in, drawings through final inspection. A well-specified garage conversion for the same square footage runs $145,000 to $210,000. The $30,000-$75,000 gap is real, but it shrinks when the existing garage has significant foundation, structural, or utility problems. It can also shrink when a prefab or modular system like an Abodu or Cover unit is specified for the Carport Conversion or detached build – those systems can bring the detached ADU cost down by 10-20% on the construction side, with the trade-off of longer lead times and less design flexibility.
Ellery specifies and coordinates prefab systems from Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie under the same single contract. So if a site assessment shows the existing garage has more problems than the conversion is worth, a prefab detached option is not a separate vendor relationship – it is a different spec in the same drawing set and the same written price.
Return on Investment: Does a Garage Conversion ADU Pencil in Long Beach?
Long Beach rental data from early 2026 shows studio and one-bedroom units renting in the $1,600-$2,400 range depending on neighborhood and finish. Belmont Shore and Naples command the top of that range. North Long Beach and Wrigley sit closer to $1,600-$1,900. A garage conversion that costs $130,000 all-in and rents for $1,800 per month generates a gross annual yield of about 16.6% on the construction cost – before financing. That does not include the property value increase, which appraisers in the Long Beach market typically calculate at 100-150x gross monthly rent added to the assessed value of the main property.
These numbers are not a guarantee – rental markets move, interest rates change, and property conditions vary. But they explain why Long Beach homeowners who bought between 2015 and 2022, and are now sitting on equity, are treating garage conversion ADUs as a capital allocation decision rather than a home improvement project.
FAQs: Garage Conversion ADU Cost in Long Beach
How much does a garage conversion ADU cost in Long Beach, CA?
A garage conversion ADU in Long Beach costs $95,000 to $210,000 all-in, drawings through final inspection, depending on garage size, existing conditions, and finish level. A single-car conversion typically runs $95,000-$140,000. A two-car conversion to a full one-bedroom unit typically runs $145,000-$210,000. Every Ellery project is quoted with a written price before any work begins. Call (562) 414-4842 for a written estimate on your specific property – estimates are free.
How long does a garage conversion ADU take in Long Beach?
From signed contract to final inspection, a typical Long Beach garage conversion takes 8 to 14 months. The permit process currently runs 6-10 weeks at Long Beach Development Services for a standard submittal; projects in the coastal zone or requiring a variance add 3-6 months. Construction itself, once permitted, takes 10-16 weeks for a typical single-car conversion and 14-20 weeks for a larger two-car project. Ellery quotes a realistic timeline at the proposal stage, in writing, calibrated to current Long Beach plan check backlogs – not to what you want to hear.
Do I need a permit for a garage conversion ADU in Long Beach?
Yes. A garage conversion to habitable ADU space requires a full building permit from the Long Beach Development Services Department, including plan check for architectural, structural, mechanical, electrical, and plumbing. There is no legal path to a permitted ADU in Long Beach without a complete permit set. The permit is also what creates the legal, financeable, insurable ADU – an unpermitted conversion is not a rentable unit and carries real liability. Ellery’s permit set is the core deliverable on every project; it is not optional or separate from construction.
Is it cheaper to convert a garage or build a new detached ADU in Long Beach?
Garage conversions are usually $30,000-$75,000 less expensive than a comparable new detached ADU in Long Beach, because you are working with an existing foundation, roof, and four walls. That gap shrinks when the existing garage has significant structural or utility problems – and sometimes a Garage Conversion ADU in Long Beach and a new prefab detached unit end up within $20,000 of each other once site conditions are factored in. Ellery prices both options transparently in the same written proposal so you can make the decision with real numbers, not estimates built to win the job.
What Long Beach permit fees should I budget for an ADU?
Budget $4,500 to $9,500 for Long Beach building permit fees on a standard garage conversion ADU. This covers plan check (charged at approximately 65% of the permit fee), building permit, and separate mechanical, electrical, and plumbing permits. School impact fees are waived for most ADUs under 750 square feet under California law. Projects in the coastal zone may have an additional Coastal Development Permit fee of $2,000-$5,000 through the California Coastal Commission. Ellery itemizes all permit fees in the written proposal – they are not buried in a general allowance.
What is included in Ellery’s price for a garage conversion ADU?
Ellery’s written price covers the full design-build scope under one contract: architectural drawings, permit set, Title 24 energy calculations, city permit fees, foundation work, framing, roofing, electrical, plumbing, HVAC, insulation, drywall, windows and doors, kitchen and bath installation, flooring, and site utility connections. There is no designer-versus-builder split, no allowance placeholder for major line items, and no scope additions at the door. Under Haven Standard Clause 1, the price in the proposal is the price on the final invoice. Call (562) 414-4842 to get that written price on your garage.
Key Takeaways
- Garage conversion ADUs in Long Beach cost $95,000-$210,000 all-in, depending on size and conditions.
- The biggest cost drivers are slab condition, electrical service capacity, and distance from sewer and water lines – all assessable before drawings start.
- Long Beach permit fees run $4,500-$9,500; coastal zone projects add $2,000-$5,000 and significant timeline.
- Finish level is the most controllable budget variable: builder-grade finishes run $14,000-$20,000; owner-occupant premium finishes run $28,000-$38,000 for kitchen and bath combined.
- Written price before work starts is not a bonus – it is the baseline every project deserves, and it is Haven Standard Clause 1 on every Ellery project.
- A 365-Day Done Right Promise, backed in writing, means if the finished ADU is not built to the permitted drawings, Ellery makes it right.
- A free second opinion is available on any written estimate you already have – call (562) 414-4842.
Get a Written Price on Your Long Beach Garage Conversion
Nadia Ellery and the Ellery ADU Studio team have designed, permitted, and built more than 900 ADUs since 2015, every one with a written price before work started and a documented photo record when work was complete. If you have a garage in Long Beach and want to know what a conversion would actually cost on your specific lot – slab condition, panel capacity, plumbing access, permit fees, and all – call (562) 414-4842. A live person answers. No voicemail, no callback promise. You will leave the call with a clear picture of what your project involves and a path to a written estimate. If you already have a competitor’s quote in hand, bring it – the free second opinion is there to help you read it clearly.
Pricing reflects the Long Beach market as of 2026. Ellery ADU Studio Long Beach offers free estimates – call (562) 414-4842.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Long Beach since 2015.
What Our Customers Say
"Handled the whole planning process. We went to one hearing and that was it."
- Rowena C."The rental income has covered the payment since the second month. They were realistic about the numbers rather than optimistic."
- Odette N."Garage conversion finished on the drawings and close to the schedule. They were honest that the sewer connection was the unknown, and it was."
- Arjun D.