A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateTrusted ADU Builders for Long Beach Homeowners
Adding an accessory dwelling unit in Long Beach typically costs between $180,000 and $450,000 for a turnkey detached unit, and the two factors that move that number most are site conditions and whether you choose a prefab or site-built path. We’re Benson ADU Long Beach, part of the Relay Home Co. family founded in 2006, and we’ve spent years helping homeowners across Long Beach, Lakewood, Signal Hill, and Cerritos turn underused backyard space into rental income, guest quarters, or a dedicated home office. Our job is simple: give you a written price before any work starts, build with brands you can research yourself, and stand behind the finished project for a full 365 days. Call (562) 362-3885 and you’ll reach a live person, not a voicemail loop.
ADU Construction
ADU Construction is the full process of building a legal secondary dwelling on your property, from foundation and framing through drywall, electrical, plumbing, and final inspection. Long Beach homeowners pursue ADU construction for three main reasons: housing an aging parent, generating rental income (a one-bedroom ADU in Long Beach commonly rents for $1,800 to $2,400 per month), or creating a workspace separate from the main house. Benson ADU Long Beach, our ADU Builders in Long Beach, handles the entire construction sequence under one written price, so you’re not juggling a designer, a structural engineer, and a general contractor on separate invoices. Expect total ADU construction in Long Beach to run $180,000 to $450,000 depending on size, finish level, and whether you choose prefab or site-built.
Prefab vs. Site-Built
Prefab ADU construction uses factory-built wall panels or complete modules delivered to your property, which cuts on-site framing time by weeks and reduces weather-related delays. Site-built means the entire structure is framed on your lot, which allows more design flexibility but takes longer. We’re authorized to build with Abodu, Plant Prefab, and Tuff Shed, so you can compare prefab options against traditional framing before committing.
Permits and Setbacks
Long Beach follows California state ADU law, which means a setback of 4 feet from side and rear property lines for most detached units, though your specific zoning may vary. We handle the permit drawings, submittals, and corrections as part of the construction contract. Troy Eastman, our owner, walks every client through the permitting path for their specific lot before any money changes hands.
Detached ADU
Detached ADU means a standalone unit completely separate from your main house, usually built in the backyard where a garage, shed, or open lawn currently sits. This is the most popular ADU type in Long Beach because it gives you full rental privacy, a separate entrance, and no shared walls with family members or tenants. Detached ADUs in Long Beach typically cost $200,000 to $450,000 for a completed unit of 400 to 800 square feet, with the lower end representing a prefab unit like Abodu or Plant Prefab and the upper end a fully custom site-built design with upgraded finishes.
Site Requirements
Your Long Beach lot needs enough usable backyard space to meet setback requirements and still leave you a functioning yard. We measure the buildable envelope during the first site visit and tell you exactly what square footage your lot can support before you pay for plans. Many Long Beach lots built in the 1940s and 1950s have irregular dimensions, so we check the actual survey, not just the county parcel map.
Foundation Options
Detached ADUs can sit on a poured slab, raised foundation, or pier-and-beam system depending on your soil and drainage conditions. In neighborhoods like Bixby Knolls and Los Altos where older homes sit on raised foundations, a matching raised foundation often makes the ADU feel like it belongs. We explain the cost difference between foundation types in your written estimate, line by line.
JADU
JADU stands for Junior Accessory Dwelling Unit, which is a smaller conversion carved out of the existing footprint of your main house, usually a garage conversion or a sectioned-off portion of the first floor. A JADU maxes out at 500 square feet and is the cheapest path to a legal rental unit in Long Beach, often running $80,000 to $150,000 for a garage conversion with a bathroom and kitchenette. Benson ADU Long Beach builds JADUs for homeowners who want rental income without the higher price tag of a detached build, and the shorter construction timeline means you’re collecting rent months sooner.
Garage Conversions
Converting an attached garage into a JADU typically costs less than any other ADU type because the structure, roof, and one wall already exist. The work focuses on insulation, electrical, plumbing for a bathroom, and replacing the garage door with a wall and window. A JADU of this type in Long Beach usually rents for $1,400 to $1,800 per month.
Owner Occupancy Rule
California JADU law requires the owner to live in either the main house or the JADU, which makes this option best suited for homeowners planning to stay on the property long term. We walk you through this requirement before you commit so there are no surprises at the permit counter. Troy Eastman makes sure every JADU client understands the occupancy rules in writing before construction begins.
ADU Plans
ADU Plans are the architectural and engineering drawings required to obtain a building permit from the City of Long Beach, including site plans, floor plans, structural calculations, and utility layouts. You need complete, code-compliant ADU plans before any construction work can legally begin, and plan quality directly affects permit approval speed and construction accuracy. Benson ADU Long Beach includes professional ADU plans in every project scope, typically valued at $8,000 to $25,000 depending on the complexity of the design and the number of revisions. We don’t hand you a brochure and say good luck; we produce actual construction documents stamped by licensed professionals.
What Plans Include
A complete ADU plan set covers site orientation, floor layout, elevations, electrical placement, plumbing routing, and structural details specific to your lot. The plans also show compliance with California energy code (Title 24), which Long Beach enforces for all new ADUs. If you already have plans from another source, we review them line by line and flag anything that will get bounced at the permit counter.
Plan Revisions and Resubmittals
Most Long Beach ADU permit applications come back with correction requests, and each resubmittal adds time to the process. Our team handles corrections directly with the city so you don’t have to interpret building code language. The written price for your ADU includes plan revisions through permit approval, not just the first submission.
ADU Contractor
ADU Contractor is the general contractor responsible for executing the entire ADU build: hiring and managing subcontractors, ordering materials, scheduling inspections, and keeping the job on time and on budget. Long Beach homeowners typically choose between a design-build firm like us, a general contractor who works from plans you supply, or a prefab manufacturer that installs their own product. Benson ADU Long Beach functions as a design-build contractor, which means one contract, one point of contact, and one written price covering plans, permits, and construction from start to finish.
Choosing the Right Contractor
The most important question to ask any ADU Builders Maintenance Checklist for Long Beach Homeowners candidate is whether they’ll put the full price in writing before construction starts. Verbal estimates are how five-figure change orders happen. We provide a written price for the entire project scope, and our 365-Day Done Right Promise is stamped on every contract, meaning any defect within a year gets corrected at our cost.
Who Shows Up at Your Property
Every technician and subcontractor we send to your Long Beach property is background-checked and arrives in uniform, so you always know exactly who is walking onto your lot. We message you before arrival with a name and live ETA, the same way you’d track a rideshare. The person answering your calls is a live person, any hour of the day, every day of the year.
ADU Design
ADU Design is the architectural planning phase that determines the size, layout, exterior appearance, and interior configuration of your unit before construction begins. Good ADU design maximizes usable square footage within Long Beach’s setback and lot coverage rules, and it positions windows, doors, and utilities in ways that actually function for daily living. Benson ADU Long Beach approaches design with the same transparency as construction: we show you 3D renderings, plan views, and material samples, then give you a written design cost that typically falls between $8,000 and $25,000 as part of the full project scope.
Design Options We Offer
We design both custom site-built ADUs and adapt the factory floor plans from Abodu, Plant Prefab, and Tuff Shed, giving you a range of layouts from studio to two-bedroom. Prefab design saves money because the engineering already exists and only needs site adaptation, while custom design lets you match the architectural character of your main house. You see both options priced side by side before you pick.
Matching Your Main House
Long Beach homes span Spanish Revival, Craftsman, mid-century ranch, and contemporary styles, and an ADU that clashes with the main house can hurt resale value. We use James Hardie fiber cement siding in a range of profiles and colors that can be painted to match or complement your existing exterior. The goal is an ADU that looks like it belongs on your lot, not a box that landed there.
Backyard ADU
Backyard ADU is the term Long Beach homeowners use for any detached accessory dwelling unit built in the rear yard, whether it’s a converted garage, a prefab unit, or a fully custom structure. This is the most flexible ADU category because you’re starting from open space, which means fewer structural compromises than a JADU and full control over size, orientation, and privacy. A backyard ADU in Long Beach generally costs $200,000 to $450,000 all-in, with prefab options from Abodu and Plant Prefab landing at the lower end and custom builds at the higher end.
Maximizing Small Backyards
Many Long Beach lots are 50 feet wide by 120 feet deep or smaller, which leaves a tight building envelope once you account for setbacks and the existing house footprint. We specialize in compact ADU footprints between 400 and 600 square feet that still deliver a full kitchen, bathroom, and comfortable living space. A well-laid-out 500-square-foot unit feels larger than a poorly planned 700-square-foot one.
Utility Connections
Running electrical, water, and sewer lines to a backyard ADU is often the most expensive single line item, especially on Long Beach lots where the main house is far from the rear property line. We include that trenching and connection work in your written price instead of leaving it as an open-ended cost. In areas with clay-heavy soil like parts of East Long Beach, we trench with wider margins to avoid settling issues down the road.
Brands We Service
We build with Abodu, one of the most recognizable prefab ADU brands in California, whose factory-built units arrive on-site with framing, windows, and exterior already complete. Our install teams have assembled Abodu units on tight Long Beach lots where crane access was limited, and we handle the foundation, utility connections, and finish work that turn a delivered module into a move-in-ready home.
We also work extensively with Plant Prefab, whose panelized construction system gives you more design flexibility than a fully modular unit while still cutting on-site framing time. If you’re considering a Tuff Shed structure as a base for a backyard studio or office conversion, we can assess whether it makes sense as a starting point or whether ADU Builders - Seal Beach style purpose-built ADU is the better investment. Whether you have an Abodu, Plant Prefab, Tuff Shed, or any other make, we can evaluate it, price the work, and put it in writing.
Signs You Need a Pro Right Now
- Your permit application has been rejected twice. Long Beach plan checkers return corrections for specific code issues, and repeated rejections usually mean something structural isn’t right. We review the correction letters, fix the drawings, and resubmit correctly the first time.
- You’ve gotten three verbal estimates with wildly different numbers. When one contractor says $150,000 and another says $350,000 for the same described project, someone isn’t pricing the full scope. We give you a written line-item price so you can compare apples to apples.
- Your garage has foundation cracks or water intrusion. A garage conversion JADU requires a stable, dry base, and existing cracks or moisture mean remediation work is needed before framing starts. We inspect the slab and tell you honestly whether it’s salvageable or whether a full replacement makes more sense.
- Your backyard drains toward the house. Poor drainage affects foundation design and can cause flooding issues for a detached ADU. We check the grade during the site visit and build drainage provisions into the written price instead of discovering standing water after the slab is poured.
- A previous contractor walked off mid-project. Unfinished ADU construction is a common problem in Long Beach, and we regularly take over half-built projects. We assess what’s been done, flag code violations from the previous work, and price out the completion path in writing.
Our Process, Step by Step
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Site Assessment and Feasibility. We visit your Long Beach property, measure the buildable area, check setbacks, assess utility access, and evaluate drainage. You get a written feasibility summary that states exactly what size ADU your lot can support and what it will cost. This step is free.
- 2
Written Price and Scope. We produce a line-item written price covering plans, permits, foundation, construction, utilities, finishes, and cleanup. You review it line by line, ask questions, and sign only when the number matches your budget. No work starts without a signed written agreement.
- 3
Design and Permitting. Our design team produces the full ADU plan set and we submit it to the City of Long Beach. We handle all corrections and resubmittals. You get updates by text or email every time there’s movement at the permit counter.
- 4
Construction and Real-Time Updates. Our background-checked crew builds your ADU with scheduled progress updates, photo documentation, and live arrival times for every inspection. You see the work happening, not just hear about it later. Milestone invoices are paid by link, and the final invoice matches the written price.
- 5
Final Inspection and 365-Day Coverage. We walk the finished unit with you, address any punch list items, and hand over the written 365-Day Done Right Promise. If anything covered fails within the year, we return and fix it. A free second visit is part of the guarantee on any covered repair.
How Much Does ADU Builders Cost in Long Beach?
A typical detached ADU in Long Beach runs $200,000 to $450,000 depending on size, finish level, and whether you choose prefab or site-built construction. A JADU garage conversion runs $80,000 to $150,000. ADU plans alone typically cost $8,000 to $25,000 when priced separately, though we include them in the full project scope. Monthly rental income for a one-bedroom ADU in Long Beach commonly lands between $1,800 and $2,400, which gives most owners a payback period in the 8 to 15 year range before property appreciation.
What moves the price most: foundation type (slab vs. raised), utility trenching distance, kitchen and bathroom finish levels, and whether your lot requires any retaining walls or drainage work. Prefab units from Abodu or Plant Prefab typically cost less than site-built because factory assembly reduces labor hours and weather delays. Custom site-built ADUs cost more but allow full design control.
How to avoid overpaying: get a written line-item price instead of a verbal estimate, confirm that plan revisions are included through permit approval, and ask whether utility connections are priced in or billed as an extra. Our free estimate includes a site visit, a written scope, and an itemized price. Call (562) 362-3885 to schedule yours, or visit our home page to see more about how we work.
Our Service Area Near Long Beach
Benson ADU Long Beach serves homeowners across Long Beach and the surrounding communities, including Downey, Buena Park, Lakewood, Signal Hill, Cerritos, Seal Beach, Artesia, La Palma, Bell, La Mirada, and West Rancho Dominguez. We schedule site assessments within a few business days of your call, and our live phone team can answer questions any hour of the day. Each location is independently owned and operated under the same Relay Visibility Guarantee, so the written-price promise holds no matter which community you call from.
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.
Frequently Asked Questions About ADU Builders in Long Beach
ADU Builders refers to contractors who specialize in designing, permitting, and constructing accessory dwelling units on residential properties. In Long Beach and nearby, that means detached backyard units, garage conversions, and JADUs built to California state ADU law, including work by our ADU Builders in Signal Hill. We handle the full process under one written contract, from site assessment to final inspection.
Most ADU projects in Long Beach take 6 to 12 months from signed contract to move-in, with prefab units trending faster and custom site-built units taking longer. Permitting alone typically takes 2 to 4 months depending on plan check workload and correction cycles. We’ll give you a written timeline with your written price. Call (562) 362-3885 for a project-specific schedule.
A detached ADU runs $200,000 to $450,000, a JADU conversion runs $80,000 to $150,000, and plans cost $8,000 to $25,000 when priced separately. Your specific number depends on site conditions, utility distances, and finish choices. The estimate we give you is free and comes in writing.
Yes. We’re authorized to build with Abodu, Plant Prefab, and Tuff Shed, and we regularly install and finish units from all three manufacturers. We can evaluate existing prefab units for retrofit work too. Call (562) 362-3885 to discuss your brand preference.
A live person answers our phone line 24 hours a day, 7 days a week, every day of the year. You won’t get a voicemail loop or an automated attendant. For construction scheduling, site visits are arranged during business hours, but urgent questions about an active project are answered anytime.
Every Benson ADU Long Beach project carries the 365-Day Done Right Promise: if any covered work isn’t right within a full year, we fix it at our cost. The guarantee is written into your contract, not described verbally. If a covered repair fails, you get a free second visit to make it right.
Clear the build area of personal items, know where your utility lines enter the property, and have your property survey available if you have one. We handle the rest, including utility locating and site protection. We’ll send you a prep checklist before construction starts so nothing gets overlooked.
Schedule Your ADU Builders Service in Long Beach Today
You deserve a written price before any work starts, and that’s exactly what you’ll get from Benson ADU Long Beach. Call (562) 362-3885 to schedule your free site assessment and written estimate, or explore our ADU Builders in Long Beach page for more details. Troy Eastman and our team will walk your lot, answer every question, and hand you a number in writing before you commit to anything.
Written by Troy Eastman, Owner at Benson ADU Long Beach, serving Long Beach homeowners with transparent ADU construction since joining the Relay Home Co. family in 2006.
