A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Alhambra, CA
Fielding ADU Builders builds accessory dwelling units, garage conversions, and room additions in Alhambra, CA. Most of the homes here were built between the 1920s and 1960s, which means small lots, detached garages off the alley, and foundations that have settled over decades. That changes how an ADU gets designed, permitted, and built. If you’re weighing a backyard unit or converting the garage your family uses for storage, call (361) 315-4177 and we’ll walk you through what’s realistic for your property.
Why Alhambra Homes Are Different
Alhambra’s housing stock runs older than most of the San Gabriel Valley. A large share of single-family homes sit on 5,000-to-7,500-square-foot lots, several with detached garages accessed from the rear alley, and many were built long before current setback and fire-sprinkler codes existed. That matters for ADU work because the city’s planning check will look at things the original builder never considered: rear-yard coverage, distance from the main house to the proposed unit, and whether the existing garage slab can support a conversion without a new pour. We see this on nearly every job in the neighborhoods south of Main Street and east of Garfield Avenue.
Alhambra also sits in a mild climate with hot, dry summers, which means cooling matters as much as heating in a backyard unit. We typically spec mini-split systems for detached ADUs because a central extension off the main house rarely pencils out. Soil here is a mix of sandy loam and clay sections; some lots near Almansor Park and the northern hills need deeper footings than a standard plan assumes. Those are exactly the details a written price needs to account for before the work starts.
Our Main Alhambra Services
Most Alhambra homeowners call us for one of three things: adding square footage to the existing house, turning an underused garage into living space, or building a detached unit in the backyard. Each has its own Alhambra page with pricing and local detail.
Room Addition Contractor in Alhambra
A room addition in Alhambra usually means extending the rear or side of a 1940s-to-1970s home, matching roof lines and stucco, and pulling a building permit that accounts for the new foundation. Older lots here often trigger a review of the existing electrical panel, which may need an upgrade before the inspector signs off. We handle the full scope, from plans and permit to finish, and we price it in writing before any work begins. Read more on our Room Addition Contractor in Alhambra page.
Garage Conversion Contractor in Alhambra
Many Alhambra garages are detached, alley-loaded structures that were never insulated, never plumbed, and never intended for habitation. Converting one means new subfloor, electrical, insulation, and often a sewer lateral tie-in that crosses the whole rear yard. The city will check that you’re not losing required covered parking unless you add it back or qualify for an exemption. For the numbers and a breakdown of what the job involves, see our Garage Conversion Contractor in Alhambra page.
ADU Builders in Alhambra
A detached ADU in Alhambra typically runs 400 to 800 square feet of new construction in a backyard that has to keep working around mature trees, utility lines, and the existing house. Setback rules and lot-coverage limits shape the footprint early, and we design to them from the first site visit rather than drawing something the city will reject. We also work with prefab and modular platforms when the lot and budget favor them. Full detail and pricing are on our ADU Builders in Alhambra page.
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.
Brands We Service in Alhambra
We install and finish units from Abodu, Cover, and Dvele, and we specify James Hardie siding on most conventional builds. Parts and materials for these platforms are ordered direct and staged in advance, so a typical Alhambra project doesn’t stall waiting on a panel or a trim detail. See our brands for the full list.
Pricing for ADU Company in Alhambra, CA
| Service | Typical range in Alhambra |
|---|---|
| Detached ADU, 400 sq ft | $140,000 – $190,000 |
| Detached ADU, 600 sq ft | $185,000 – $250,000 |
| Detached ADU, 800 sq ft | $230,000 – $310,000 |
| Garage conversion (full, permitted) | $85,000 – $140,000 |
| Garage conversion (finish existing shell) | $55,000 – $85,000 |
| Room addition, 300 sq ft | $90,000 – $135,000 |
| Room addition, 500 sq ft | $140,000 – $200,000 |
| Site prep and foundation only | $18,000 – $35,000 |
| Permit and plan set for ADU | $6,000 – $12,000 |
| Utility tie-in (sewer, water, electrical) | $8,000 – $18,000 |
In Alhambra, the two things that push a job toward the top of these ranges are soil conditions and the age of the existing electrical panel. Older panels often need a service upgrade before the city will sign off, and clay-heavy sections of the lot can deepen the footing requirement. That’s why we put the full price in writing before any work starts: the number you approve on day one is the number on the final invoice.
Neighborhoods We Serve in Alhambra
We work across the city, including the areas where ADU and addition inquiries come up most often.
- Midwick Tract
- North Alhambra
- Almansor Park area
- Central Alhambra near Main Street
- Ramona Park neighborhood
Response time for estimates in Alhambra is typically one to three business days, depending on site-visit scheduling.
Service Area – Cities Near Alhambra
If you’re just outside the Alhambra line, we also cover South Pasadena, CA, San Marino, CA, Monterey Park, CA, and San Gabriel, CA. Each city has its own permit office and its own quirks, and we work inside those rules.
Serving Alhambra, CA - Our Local Coverage Area
We’re based in the Alhambra 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 Company in Alhambra
After the site visit and written estimate, most Alhambra jobs begin with plans and permit submittal, which usually takes four to eight weeks depending on city workload. Construction start follows permit approval. Call (361) 315-4177 and we’ll give you a realistic timeline for your specific lot.
No, not in most cases. California state law limits an HOA’s ability to block an ADU, and that applies in Alhambra. If your property is in an HOA, we help you prepare the notice they’re entitled to, but the city permit is what drives the timeline. Call (361) 315-4177 to talk through your situation.
We handle the entire job, from plans and permits through final inspection. The price we give you in writing covers the scope we agree on, and the Garrison Standard backs the work for 365 days. If something fails inside that year, we return and correct it at no charge. Call (361) 315-4177 for a free estimate.
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 Alhambra Customers Say
"Insulation, drywall, and finishes were all well done. Feels like part of the house."
- Pete O."Built a detached ADU behind our house. The builder is a veteran and runs the site like a platoon: schedule posted, crew on time, everything labeled. Finished within a few days of the date."
- Ken W."Room addition over the back patio. Framing is square, windows are tight, and the roofline matches."
- Danny L.
