Free in-home visit & sketch
We walk your lot or space, talk through what's possible, and sketch options on the spot. Free. No obligation.
ADU & Home Additions
ADU Construction & Home Additions in the SGV Foothills
25 years adding space to foothill homes. ADUs, room additions, second stories and interior expansions — designed, permitted and built in-house from first sketch to final inspection.
- ADU design, permitting & construction
- In-house design
- We handle city permits start to finish
- Fixed-price quote, written timeline
Request Your Free Estimate
We come to you, listen, and leave you with an honest written quote. No pressure. No obligation.
CSLB #1045801 · Licensed & Insured
CSLB #1045801 Licensed & Insured ★★★★★ 4.6 on Google 25 Years in the Trades In-House Design
Why Dollhouse
More space, fully permitted, built to last.
Whether it's a backyard ADU for rental income or family, a primary-suite addition, or opening up the floor plan, the hard part is rarely the building — it's the design and the permits. Our architect handles both in-house, so your addition resolves as one integrated plan and clears inspection the first time.
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Recent Foothill Projects
Real Dollhouse ADU Construction & Home Additions across the SGV
Every project below was designed, permitted, and built by our in-house team. No stock photography. No subcontractor handoffs.
How It Works
Three steps. No surprises.
The same process we've used on every foothill project for the last 25 years.
Design, permits & written quote
Our architect draws the plans and we pull every permit with your city, with a fixed quote and timeline before you sign.
One crew builds it & walks it weekly
Foundation, framing, systems and finish — all in-house, weekly walkthroughs, one point of contact.
What It Costs
Honest ranges, not vague "it depends."
Your exact number comes from the free in-home visit. Here's how most foothill projects break down:
Interior addition
Opening walls, bump-outs and reconfiguring existing square footage.
Room / suite addition
New attached square footage — bedroom, primary suite, family room.
Detached ADU
Full accessory dwelling unit with its own systems, designed and permitted.
Every quote is line-item and fixed in writing before you sign. Financing available.
The Dollhouse Promise
Three guarantees that take the risk off your project.
Fixed-Price Quote, In Writing
The number on your contract is the number you pay. The budget you sign is the budget that closes the job.
On-Time Finish, In Writing
Your start and finish dates go in the contract. Run past finish day on us, and we credit you. No vague excuses.
5-Year Workmanship Warranty
Our work carries a five-year Dollhouse warranty on top of every manufacturer warranty. One call, we make it right.
Common Questions
Straight answers, no upsell.
Do you handle ADU permits and plans?
Yes — all in-house. Our architect draws the plans and we manage the entire permit process with your city. You don't coordinate anything.
How long does an ADU take?
Design and permitting typically run a few months depending on your city; construction is usually 4-7 months. We give you both timelines in writing up front.
Can you do a second-story addition?
Yes, where the existing structure and lot allow. Our architect runs the structural assessment as part of the design phase.
Are you licensed and insured?
Yes. CSLB License #1045801. Insured. Verify at cslb.ca.gov.
Where We Build
Serving the San Gabriel Valley foothills.
Our crew lives here. If you're inside a 25-mile radius of San Dimas, you're in our service area: San Dimas · Glendora · La Verne · Claremont · Upland · Rancho Cucamonga · Pasadena · Arcadia · San Marino · Sierra Madre · Monrovia · Bradbury · Covina · Azusa · Duarte · Walnut · Diamond Bar · Chino Hills.
Ready when you are
Let's talk about your project.
Tell us what you're planning and we'll come to your home, listen, and leave you with a clear, honest, written estimate. No pressure. No obligation.
(626) 991-8219 Talk to the owner. Mon–Sun, 9am–10pm.
Request Your Free Estimate
1-business-day response.