Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across Temple City
A room addition or ADU in Temple City typically runs $45,000-$130,000 for a standard addition, $90,000-$220,000 for a new detached ADU, and $30,000-$80,000 for a garage conversion. Most projects take 4-9 months from first drawing to final inspection, depending on whether you’re working with an existing slab or pouring new footings. We answer the phone when you call, and we’ll walk your lot before we quote a single number.
Temple City’s housing stock sits right at the intersection of old and new. Half the lots still hold 1950s and 60s ranch homes on original slabs. The other half are fresh two-story custom builds, many commissioned by buyers with very specific design requirements around layout, door placement, and how a staircase meets the entry. Barrett & Sons has built additions and ADUs across 91780 for years, and Tom Barrett’s crew knows what a soil report says before the architect even asks. Call (877) 610-1318 for a free estimate, and we’ll come walk the property.
Why Barrett & Sons Construction Is Temple City’s Preferred Home Additions & ADU Company
The teardown-rebuild wave in Temple City is not slowing down, and neither are the phone calls from homeowners who bought what they thought was a finished house only to find the panel, the slab, or the HOA rules standing between them and the space they actually need. We’ve worked on homes off Las Tunas Drive, north of Live Oak Avenue, and throughout the neighborhoods around Temple City Park. The clients we work with here are not looking for the cheapest number. They’re looking for a contractor whose name is on the truck and whose sons run the crew, because the last outfit they hired quoted one price on the phone and showed up with another.
Tom Barrett founded this company in 1998 and he still walks most job sites himself. His name, his address, and his license number are published and verifiable. Every scope change lands as a written change order before work proceeds, and every completed job carries a written 90-Day Done Right Promise. If something isn’t right, one call brings Tom back. That matters in Temple City, where an addition on a 60-year-old slab is not the same job as an addition on fresh fill dirt in a neighboring city.
We answer the phone 24 hours a day, seven days a week. Not a voicemail box, not a call center in another state. A live person. That is the baseline for how we run every Home Additions & ADU project.
Our Home Additions & ADU Services in Temple City
ADU Design & Permitting
Designing an ADU in Temple City starts with a soils report if you’re adding to a 1950s slab, and it starts with an HOA architectural review if you’re in one of the newer planned developments. We handle both. Our team files the permit drawings, walks them through LA County plan check, and gets the inspection sign-off before anyone moves in. A properly permitted ADU adds rentable square footage and resale value. An unpermitted one adds a headache when you sell.

Garage Conversion ADU
A detached garage conversion in Temple City generally runs $30,000-$80,000, depending on whether the existing structure has a usable foundation and whether you need a new electrical subpanel run from the main. We see plenty of 1950s garages with slab cracks from expansive clay soil. Before we quote, we look at the floor, the roof assembly, and the panel. That’s the difference between a bid you can trust and a surprise invoice at the end.

New Detached ADU
New detached ADUs in Temple City start around $90,000 and run upward of $220,000 for high-spec builds. These are full ground-up structures, which means new footings engineered for clay soil, new gas and water runs, and a separate electrical service if your existing panel can’t carry the load. If you’re planning a two-story ADU over a garage, the structural engineering gets more involved, and so does the permit review.

Junior ADU & Interior Conversion
A junior ADU is the fastest and least expensive path to a second living space in Temple City. Converting an existing bedroom, a bonus room, or a portion of the main house into a JADU with its own entrance and kitchenette often falls in the $45,000-$130,000 range depending on finish level. It requires its own permit and its own inspection, but it avoids ground-up construction and most foundation work entirely.

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.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Temple City
We install materials you can look up, not mystery brands off the back of a van. For ADU kitchens and baths, we spec KraftMaid cabinetry with Cambria or comparable countertops, Schluter waterproofing systems on wet walls, and Grohe or Sterling fixtures where they fit the budget. If your addition involves a roofline tie-in, we use GAF roofing assemblies so the new section matches the existing shingle warranty instead of voiding it. When a Temple City client asks what something is, we can point to a manufacturer name and a spec sheet, not a shrug.
Common Home Additions & ADU Problems We See in Temple City Homes
- Slab cracks from expansive clay. Temple City sits on soil that swells with winter rain and contracts through the summer heat. Additions built without a soils report end up with cracked foundations and a very expensive change order for helical piers or deepened footings. We order the report before we pour anything.
- 60-amp and 100-amp original panels. Nearly every 1950s ranch in Temple City was built with a panel sized for a refrigerator and a couple of lamps. Adding an ADU kitchen and bath to that panel without a subpanel upgrade will trip breakers constantly, or worse. We plan the electrical draw before framing starts.
- HOA architectural review stops work. Several Temple City developments require submitted renderings and design-committee approval before any structural change. We’ve seen stop-work orders on second-story additions because a homeowner skipped that step. We file the HOA package at the same time we pull permits.
- Asbestos tiles and vermiculite in pre-1978 originals. Demolition on a Temple City ranch often reveals materials that require licensed abatement before framing can proceed. That’s not a surprise if the contractor knows what they’re looking at. It’s a budget line item from day one instead of a panic on demo day.
Pricing for Home Additions & ADU in Temple City, CA
Here are the numbers we quote in Temple City based on current permit fees, material costs, and local labor rates. These are real ranges, not averages pulled from a national database.
| Project Type | Typical Range in Temple City |
|---|---|
| Home Addition | $45,000-$130,000 |
| ADU Construction | $90,000-$220,000 |
| Garage Conversion ADU | $30,000-$80,000 |
What moves the number is the foundation. A room addition on a stable, engineered footing costs less than one requiring helical piers through clay. A garage conversion that can reuse the existing pad costs less than one that needs a new slab. We quote fixed pricing with written change orders before any scope shift touches the job. No allowance that isn’t on paper. Call (877) 610-1318 and we’ll walk your lot, review your soils report if you already have one, and put a real number in front of you.
We Also Serve Cities Near Temple City
If you’re searching for Home Additions & ADU in Temple City, chances are good you already know the neighborhood. We also serve Rosemead, San Gabriel, Arcadia, and East San Gabriel. Same crew, same written change orders, same 90-Day Done Right Promise. If you’re a few miles outside 91780, call and ask. Chances are we already work your street.
Serving Temple City, CA - Our Local Coverage Area
We’re based in the Temple City 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 Temple City
Pull the original foundation plan and get a soils report. Temple City homes from the 1950s sit on slabs poured over expansive clay that has shifted for 70 years. Before anyone draws an ADU, you need to know whether that slab can support new loads or whether you need engineered footings. We order the soils report as part of our site walk, not after you’ve signed a contract.
Maybe. Several Temple City developments require architectural review before a garage conversion can proceed, and the design committee wants to see renderings, not a verbal description. Some HOAs prohibit converting the only covered parking space if it reduces off-street parking below the development minimum. We file the HOA package at the same time we file with the city, which keeps the review from stalling the permit clock. Call (877) 610-1318 and we’ll help you read your CC&Rs before you spend a dollar on drawings.
Get every allowance and every scope change in writing before work proceeds. A written change order is the only thing that protects you when the framing reveal shows a rotted header that wasn’t on the original bid. We’ve been doing this since 1998, and our contracts include a line that says any price change arrives in writing before a single nail moves. An allowance that isn’t on paper is a surprise waiting for a date.
A front door facing a staircase, a primary bedroom over a garage, or a main entry aligned with an unlucky compass bearing. If these matter to you, say so at the design meeting, not at framing. We’ve built enough Temple City second-story additions to know that pulling the staircase back from the entry or rotating a wall by four feet can be easy on paper and very expensive once the roof is cut. Tell us upfront and we’ll design it in from the start.
Because Temple City’s expansive clay shrinks in summer and swells in winter, and a bump-out sitting on a shallow footing will crack when the ground moves. A soils report tells the engineer how deep the footings need to go and whether you need piers. Skipping it saves $2,000 now and costs $20,000 in foundation repair later. That’s not a gamble we’ll let you take blind, and any contractor in Temple City who quotes a bump-out without one is not doing you a favor. Call (877) 610-1318 for a free estimate that includes the soils conversation from the start.
Get Your Free Estimate for Home Additions & ADU in Temple City
If you own a home in Temple City and you’re weighing an addition, an ADU, or a garage conversion, call (877) 610-1318. We’ll walk your lot, talk through the slab, the panel, and the HOA, and put a written number in your hand. No pressure, no surprise invoices, no change orders that show up after the fact. Just a straight conversation with a contractor whose name is on the truck.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Temple City and the San Gabriel Valley since 1998.







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