# ADU Builder in San Dimas | Dollhouse Construction - Business: Dollhouse Construction Inc (CSLB #1045801) - Phone: (626) 991-8219 - Page: https://dollhouseconstruction.com/adu-construction/ - Last updated: 2026-10-09 (generated from the live site copy at build time) > Backyard ADUs and garage conversions in San Dimas and nearby. Lot check, design, permits and build with one crew. CSLB #1045801. ADUs · Garage conversions · San Dimas and nearby # Your backyard ADU, start to finish. Feasibility, design, permits and build under one roof. Dallas walks your lot first. Check my lot [Call Dallas: (626) 991-8219](tel:+16269918219) - 4.6 · 19 Google reviews 25 years in the trades In-house design and our own crew CSLB #1045801 Licensed in California 4.6 · 19 reviews on Google Your options ## Four ways to add a second home on your lot. Which one fits depends on your lot, your garage and what you want it for. ### Detached ADU A new small home in the backyard. State law says the city can’t require more than a 4-foot side and rear setback for new ADUs. HCD, Apr 2026 ### Attached ADU Built onto the side or back of your house, with its own entrance. ### Garage conversion Turn the garage into a home. The city can’t make you replace the parking if the garage goes. HCD, Apr 2026 ### Junior ADU (JADU) Up to 500 sq ft, built inside your house or attached garage. One per lot. It can share a bathroom with the main house. HCD, Apr 2026 Check my lot [Addition instead? See room additions](https://dollhouseconstruction.com/room-additions/) Not sure which? That’s what the lot check is for. Floor plans ## Studio, one-bedroom, two-bedroom. Your plan is drawn for your lot. - Drawn in-house, so you see it before it is final - Sized to your lot and budget, not a catalog - Floor plan, elevations and site plan Inside the build ## Five layers between dirt and move-in. In the order it happens. Inspectors look at the work before it is covered. Your plan sets the exact schedule. Layer 1 of 5 Concept images Illustration: concept, not a photo of our work. ### Slab and foundation Soils report first, then forms, rebar and concrete. What has to be true San Dimas’s 2025 ADU handout lists a soils report from a California-licensed geotechnical engineer for a detached ADU. Its recommendations get built into the foundation. ### Framing Walls and roof structure go up. This is the day it starts to look like a house. What has to be true Inspectors look at the work before it gets covered. In San Dimas you have to get inspection approval before covering any work. ### Systems Plumbing, electrical, gas and air conditioning go in before drywall. What has to be true San Dimas’s handout lists the ADU’s sewer line tied into the main house’s building sewer (not under a structure, patio cover or porch) and a minimum 100-amp new panel. ### Roof and walls Roofing, stucco or siding, windows and doors close the building in. What has to be true San Dimas’s handout says the look must match your main house. ### Finish Drywall, cabinets, flooring, paint, fixtures, final inspection. What has to be true The handout also lists washer and dryer hookups. The lot check ## The rules we check before we draw anything. State law makes ADUs easier to approve. Your city still has rules about size, looks, utilities and fire access. San Dimas’s 2025 ADU handout lists the items below. Other cities differ, and rules change, so we confirm the current version with the city and with you on your lot. Item State law San Dimas handout What it means for you Setbacks City can’t require more than 4 ft side and rear for new ADUs 4 ft minimum side and rear Your backyard may have more room than you think. Size City can’t set a maximum below 850 sq ft (1,000 if more than one bedroom) Maximum 1,000 sq ft Size the unit to the lot and your budget, not the code. Impact fees None on an ADU under 750 sq ft; larger ADUs pay in proportion to the main house Ask the city. We check the current schedule. Keep it at or under 750 sq ft and the state says no impact fees. Lot size City can’t set a minimum lot size n/a Small lots can qualify. Soils report n/a Listed for a detached ADU A line item in your budget, early. Solar n/a A new detached ADU needs a solar (PV) system. Panels can go on the ADU or the main house. Existing panels don’t count. Plan the roof and the budget for it. Fire access n/a LA County Fire approval on a fire-flow and hydrant sheet, before the permit is issued We start that paperwork with the city and the water company. Fire hazard zone n/a In a Fire Hazard Severity Zone, the Wildland-Urban Interface code applies, with a vegetation plan Hillside lots get extra steps. Looks and doors City can only apply objective standards Must match the main house’s style. Exterior doors can’t face a property line closer than 15 ft. We design for it from sketch one. Address n/a The ADU gets its own address: yours plus the letter A Mail and emergency services find it. San Dimas’s handout is the 2025 version; state facts are from HCD’s April 2026 fact sheet. Check with the city and with us before you rely on any of this. Run the lot check on my address [Questions first? Call Dallas](tel:+16269918219) How it works ## Four phases, one person to call. Dallas talks you through the whole project before it starts. You always know which phase you’re in and what comes next. We need from you Then the final inspection, the walkthrough, and the keys. Sources: HCD ADU Handbook (Mar 2026); Terner Center. Start with the lot check [Call (626) 991-8219](tel:+16269918219) Design ideas ## What a finished unit could feel like. Straight answers ## The worries we hear most. “Will the city say no?” State law says ADUs are approved by staff against objective rules, not by a hearing, if they meet those rules. That’s why we check the rules on your lot before you spend on drawings. “Will the price jump after I sign?” You get a written, fixed-price quote before work starts. Anything outside it is a change order: written, priced and approved by you first. Items cities commonly require, like a soils report or a fire-flow sheet, are named in the quote. “What if you find something underground?” Soil, old pipes, a sewer line in the wrong place. We stop, show you, give you options and a price, and you decide before we go on. “Can I rent it out?” Usually yes. State law lets cities limit short-term rentals, and for certain ADUs any rental must be longer than 30 days. Check your city. We’re builders, not tax or legal advisers. Ask yours about rent and taxes. “Who do I call when something comes up?” Dallas. He answers his own phone. [Ask Dallas a question](tel:+16269918219) Send the lot check form Price and payments ## A written price, and payments that follow the work. ### What moves the price - Size and type of unit - Soils and foundation - How far utilities have to run - Solar requirement for a new detached ADU - Fire access on your street - Finish level A range is not a quote. The fixed price comes after design. ### Your quote, line by line One written, fixed-price quote before work starts. Items cities commonly require, like a soils report or a fire-flow sheet, are named in it. Payments follow finished work. No deposit-and-disappear. Changes are written, priced before the work, and approved by you. [Get my written estimate](https://dollhouseconstruction.com/free-estimate/) [Call (626) 991-8219](tel:+16269918219) ADU questions ## Straight answers How big can my ADU be? San Dimas’s handout lists up to 1,000 sq ft. State law says a city can’t set the limit lower than 850 sq ft, or 1,000 sq ft if the unit has more than one bedroom. Your lot and budget usually decide before the code does. Do I need a soils report? For a detached ADU, San Dimas’s handout lists one. It’s from a California-licensed geotechnical engineer and its recommendations go into the foundation design. Can I convert my garage? Often, yes. The city can’t require replacement parking when a garage becomes an ADU. Structure, slab and utilities decide the cost. We check them first. Do I need solar? A newly built detached ADU does under the California Energy Code. The panels can go on the ADU or the main house. A conversion or an addition doesn’t need them, per the city’s handout. [More questions](https://dollhouseconstruction.com/faq/) [Call (626) 991-8219](tel:+16269918219) Sources (retrieved 2026-10-06): [HCD Housing Law Fact Sheet: ADU, April 2026](https://www.hcd.ca.gov/sites/default/files/docs/planning-and-community/housing-law-fact-sheets.pdf); [City of San Dimas, ADU Requirements (2025)](https://files.sandimasca.gov/Documents/Departments/Community%20Development/Building%20and%20Safety/Forms%20and%20Handouts/2025/ADU%20Requirements%2025%20FINAL.pdf); [City of San Dimas, Homeowner’s Guide to the Building Permit Process](https://files.sandimasca.gov/Documents/Departments/Community%20Development/Building%20and%20Safety/Forms%20and%20Handouts/Homeowners-guideto-the-building-permit-process.pdf); [HCD ADU Handbook, March 2026](https://www.hcd.ca.gov/sites/default/files/docs/policy-and-research/ADU-Handbook-Update.pdf); Terner Center for Housing Innovation. Rules change. We re-check on your lot before we quote. Free to ask ## Find out what fits on your lot. Tell us your address and what you want the unit for. Dallas looks at setbacks, utilities, soils and fire access, then calls you with what works and what it would take. (626) 991-8219 Talk to the owner Link: tel:+16269918219 ## Next step - Free estimate: https://dollhouseconstruction.com/free-estimate/ - Call (626) 991-8219 (Dallas, the owner) - All files for AI assistants: https://dollhouseconstruction.com/llms.txt