Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Long Beach
A home addition in Long Beach typically runs $45,000-$130,000, while a new detached ADU runs $90,000-$220,000 and a garage conversion ADU runs $30,000-$80,000. We’re Rowan Construction Group, and our Home Additions & ADU crews serve Long Beach from our Los Angeles metro office. Call (424) 567-7009 to schedule your free estimate.
We’ve worked on homes from Bluff Park to Rose Park to the blocks near the port, and the pattern is consistent: Long Beach’s housing stock carries two histories that shape every addition and ADU we build. The 1933 earthquake rebuilt much of the city in Streamline Moderne and Depression-era construction, and decades of oil extraction from the Wilmington oil field left up to 29 feet of ground subsidence in the harbor and downtown areas. That means we’re not just adding square footage. We’re opening walls that haven’t been opened in 90 years, and we’re sometimes building on ground that has shifted.
Our process is built around that reality. We inspect first, write allowances into the contract for what we expect to find, and price any surprise in writing before we touch it. Under Clause 1 of The Haven Standard, the price is written before anyone starts. No exceptions.
Why Rowan Construction Group Long Beach Is Long Beach’s Preferred Home Additions & ADU Company
We’ve delivered over 4,000 projects since 2007, every one with a written price before work started and a documented photo record when the crew left. In Long Beach, that discipline matters more than most places because the surprises are structural, not cosmetic.
Our crews are background-checked and uniformed. A live person answers calls 24/7. And our 365-Day Done Right Promise is printed on every page, backed by a terms page, not an asterisk. If it’s not done right, we make it right.
We also offer a Free Second Opinion on any written estimate. Bring a competitor’s quote and we’ll review it line by line at no charge.
Dispatch and scheduling are coordinated from our Los Angeles office, but crews serve Long Beach locally. We know the difference between a 1920s craftsman on a raised foundation in Rose Park and a post-1933 rebuild in Bluff Park with minimal shear walls. That local knowledge changes what we budget for, and it changes what we find when we open the walls.
Our Home Additions & ADU Services in Long Beach
ADU Design & Permitting
ADU permits in Long Beach trigger a full code review of the existing structure, not just the new square footage. In a 1930s bungalow, that often means shear walls, updated wiring, and anchored framing once walls are open. We handle the architectural drawings, structural calculations, and permit submittals through the City of Long Beach Development Services. Our quotes include a permit contingency allowance based on the age and condition of your existing home, priced before we file.
Garage Conversion ADU
A garage conversion ADU in Long Beach runs $30,000-$80,000. The critical question is whether the existing slab and foundation meet current residential code. In neighborhoods near the harbor and downtown, we budget a subsidence-assessment line item before pulling any permit. We’ve found cracked diagonal foundation stems and utility stub-outs misaligned from original plans in that zone often enough that we don’t guess. If the slab is sound, we convert. If it’s compromised, we price the fix in writing before we start.
New Detached ADU
A new detached ADU in Long Beach runs $90,000-$220,000. These are ground-up builds, which means full foundation work, utility trenching, and separate meter sets. On coastal-facing lots, we specify marine-grade stainless fasteners and protective coatings for all exposed steel. The salt-laden air off San Pedro Bay corrodes standard galvanized fasteners faster than in inland neighbors like Downey or Lakewood. That’s not an upgrade. It’s a specification written into the scope.
Junior ADU & Interior Conversion
Junior ADUs convert existing interior space, typically a bedroom or attached garage, with a kitchenette and separate entrance. In Long Beach’s 1950s-1970s soft-story apartment buildings, these conversions require careful structural review. Many of these buildings are now subject to mandatory seismic retrofit ordinances, and any interior work can trigger compliance requirements. We assess the existing framing and foundation before quoting, and we write the permit scope to include or exclude seismic work based on what the city will require.
Second Story Additions
Second story additions are our most complex Long Beach projects. The existing framing, often 90 years old with no shear walls, must carry new loads and meet current seismic code. On a Streamline Moderne rebuild in Bluff Park, we opened the rear wall for a second-story addition and found the original 1934 framing had no shear walls and the salt-air corrosion had eaten the steel fasteners down to pencil thickness. After a verified inspection sign-off, we wrote the structural upgrade and marine-grade stainless fastening into the scope of work as a priced allowance, so the homeowners approved the change order in writing before we touched another stud. That’s how we work.
Room Additions & Sunrooms
Single-story room additions and enclosed patios in Long Beach must match the existing foundation type and roofline. On raised foundations common in Rose Park and Belmont Heights, we assess post-and-pier condition before designing the connection. On slab-on-grade homes near the coast, we check for subsidence-related cracking. The marine layer accelerates corrosion of steel in concrete, so we specify epoxy-coated rebar and proper vapor barriers as standard.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Before
AfterTrusted Brands We Service in Long Beach
We source across fifty-plus vetted brands, giving the written quote honest numbers rather than inflated ones. For ADU kitchens and baths, we regularly specify Toto toilets and Delta fixtures for their availability and parts support in the Long Beach market. American Standard and Blanco round out our typical ADU kitchen packages. We don’t upcharge for brand names. We specify what works, stock what breaks, and write the exact model numbers into the quote so you know what you’re getting before we order.
Common Home Additions & ADU Problems We See in Long Beach Homes
- Outdated wiring and undersized framing in 1930s rebuilds. Opening walls in a Streamline Moderne or Depression-era home triggers full electrical and structural code upgrades. The permit covers the new square footage, but the inspection covers the whole house. We budget for this.
- Salt-air corrosion of fasteners and rebar on coastal lots. The marine layer off the Pacific and San Pedro Bay is a bigger factor here than in inland neighbors. Standard galvanized steel fails early behind finished walls. We specify marine-grade stainless and protective coatings as standard, not upgrades.
- Subsidence-compromised foundations near the port and downtown harbor district. Decades of oil extraction left slabs visibly out of level, grade beams cracked in predictable diagonal patterns, and utility stub-outs misaligned with original plans. We budget a subsidence-assessment line item before pulling any permit in that zone.
- Soft-story seismic retrofit triggers on 1950s-1970s apartment buildings. Many Long Beach corridors have these buildings, now subject to mandatory ordinances. Any addition or conversion can trigger compliance. We check the city’s retrofit status before quoting.
Pricing for Home Additions & ADU in Long Beach, CA
| Project Type | Price Range in Long Beach |
|---|---|
| Second Story Addition | $45,000-$130,000 |
| New Detached ADU | $90,000-$220,000 |
| Garage Conversion ADU | $30,000-$80,000 |
These ranges reflect Long Beach’s specific conditions: older housing stock requiring structural upgrades, coastal corrosion protection, and in some zones, subsidence assessment and foundation repair. The final price depends on what we find when we inspect, which is why we deliver a written flat price with a written scope before any work starts. Under The Haven Standard, no work proceeds on a change until the change order is signed. That discipline has kept our projects within a few percent of the agreed cost across 4,000-plus jobs.
Call (424) 567-7009 for your free estimate. Bring a competitor’s written quote and we’ll review it line by line at no charge.
We Also Serve Cities Near Long Beach
Our Home Additions & ADU in Long Beach crews also work in Wilmington, Torrance, Cypress, and Cerritos. Each city has its own building department, permit timelines, and housing stock patterns, and we quote accordingly. If you’re in one of these areas, call (424) 567-7009 and we’ll schedule an inspection to give you a written price for your specific property.
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 - Home Additions & ADU in Long Beach
Long Beach’s combination of 1930s post-earthquake rebuilds with minimal shear walls, coastal salt-air corrosion protection requirements, and subsidence-compromised foundations in harbor-adjacent zones adds structural and material costs that inland cities don’t face. We write these as priced allowances in the contract, not surprises. Call (424) 567-7009 for an exact quote on your specific property - estimates are free.
Yes. In the blocks surrounding the port and downtown harbor district, we budget a subsidence-assessment line item before pulling any addition or ADU permit. Decades of oil extraction left foundation stems cracked in predictable diagonal patterns and utility stub-outs misaligned with original plans. Finding this after rough-in is done is expensive. We find it first, price the fix in writing, and get your signature before we start. Call (424) 567-7009 to schedule.
Nothing changes unless you sign a change order. We inspect before quoting, write allowances into the contract for expected conditions like outdated wiring and undersized framing, and price any surprise in writing before we touch it. Under The Haven Standard, no work proceeds on a change until the change order is signed. Call (424) 567-7009 for a written quote with allowances explained line by line.
Sometimes. If the existing slab is sound, level, and meets current residential code, we can use it. If subsidence, cracking, or inadequate depth makes it non-compliant, we price the foundation repair or replacement in writing before we start. We never assume the slab is good. We test it. Call (424) 567-7009 for a subsidence assessment and written quote.
We inspect the existing framing for shear walls, fastener condition, and load capacity, then write a structural upgrade allowance into the contract. On a Bluff Park Streamline Moderne, we found 1934 framing with no shear walls and fasteners corroded to pencil thickness by salt air. We priced the upgrade, got written approval, and proceeded. The alternative - discovering this mid-project - is how additions go over budget. Call (424) 567-7009 for an inspection and written price.
Ready to add space to your Long Beach home? Call (424) 567-7009 to schedule your free estimate. We’ll inspect your property, explain what we expect to find, and deliver a written flat price with a written scope before any work starts. That’s Clause 1 of The Haven Standard, and it’s how we’ve kept projects within a few percent of the agreed cost since 2007.
Written by Grant Rowan, Owner at Rowan Construction Group, serving Long Beach since 2007.