Read the full review →“We couldn’t believe the transformation after the garage conversion. EcoStar Remodeling & Construction turned it into a home office and gym.”
EcoStar Remodeling & Construction is an ADU builder in the Bay Area and a licensed general contractor (CSLB 1034806): we build detached backyard units, garage conversions and junior ADUs in Alameda, Contra Costa, Santa Clara and San Mateo counties, from design and permits to the finished unit. It starts with a free site visit to see what your lot allows. Request a free ADU estimate.
Detached ADU: a separate small house in the backyard with its own entrance, kitchen and bathroom. It gives the most privacy and suits rental or family use, and it needs the most site work: foundation, utility trenches and construction access. Attached ADU: an addition joined to the main house with its own entrance, often the simplest way to use a side yard or the space behind the house.
Garage conversion: an existing garage rebuilt as living space. The structure is already there, so the work centers on the slab, insulation, windows, plumbing and electrical. Junior ADU (JADU): a smaller unit created inside the existing home, such as a converted bedroom with an efficiency kitchen; because it stays within the house, it involves less new construction than a detached unit.
Not sure which one fits? We measure the lot and the existing structures on the first visit and show you which options your property allows. More on each type on our ADU builder and garage conversion pages, or see everything we build on our Bay Area page.
Most ADU projects move through the same four stages, and at each one you know what happens next.
We look at lot size, setbacks, trees, slope, the route for utility lines and access for construction, and we talk through how you plan to use the unit: rental, family, home office or guest space.
We draw the floor plan, structure and energy details the permit needs. This is where size, layout, number of bedrooms and finish level are settled, and those choices drive most of the cost.
We submit the plans to your city and handle the plan-check comments.
Cities review ADUs under the state ADU and junior ADU law published by California HCD, together with their own local standards for design, setbacks and utilities.
Some projects also need utility work, such as a new sewer connection or a larger electrical service, which we coordinate with the utility and the city.
Our crews build from the foundation up, or rebuild the garage from the inside, with city inspections at each stage.
After the final inspection we walk the finished unit with you before handover.
Read the full review →“We couldn’t believe the transformation after the garage conversion. EcoStar Remodeling & Construction turned it into a home office and gym.”
Read the full review →“Our ADU build with EcoStar Remodeling went smoothly from start to finish. Foster kept us informed, answered every question, and made sure the space was exactly what we wanted.”
Read the full review →“We needed extra space for my in laws, so we decided to turn our old garage into an ADU and EcoStar Remodeling was the only company that made us feel at ease from the very first meeting.”
Read the full review →“After months of research, we decided to go with EcoStar Remodeling and we’re so glad we did.”
Read the full review →“We recently completed a project with Eco star Remodeling and wanted to share our experience.”
We do not quote a flat price before seeing the site, because these factors move the number most:
After the site visit you get a written scope with the price and a schedule for your specific project.
Alameda: plans go to the Permit Center at City Hall, 2263 Santa Clara Avenue, Room 190, and the City preapproves detached ADU plans from qualified designers; building from one brings a faster review and a reduced application fee, with site-specific plans and engineering still required. Berkeley: the Permit Service Center is at 1947 Center Street, 3rd Floor. Oakland: applications go through the One-Stop Permit Center at 250 Frank H. Ogawa Plaza, online at any hour or in person by appointment or during walk-in hours. San Jose: permits run through City Hall at 200 E. Santa Clara Street.
State ADU and junior ADU law sits in the California Government Code (its sections were renumbered by SB 477 in 2024), and HCD’s ADU Handbook explains how cities must apply it. Within those limits each city sets its own standards for height, setbacks, parking and design, so we read your city’s current rules for your address before drawing anything.
Across Alameda, Contra Costa, Santa Clara and San Mateo counties the process is the same: we prepare the plans, file them, answer plan-check comments and schedule every inspection through to final.
Yes, we do. We are happy to give you a free quote for your project. You can expect a response within 48 hours!
Detached backyard ADUs, attached ADUs, garage conversions and junior ADUs inside the existing house, in Alameda, Contra Costa, Santa Clara and San Mateo counties.
Often, yes. A garage conversion reuses the existing structure, so the work focuses on the floor, insulation, windows, plumbing and electrical. We check the slab, framing and utility routes on the first visit.
It depends on the type of unit, the city’s plan review and the site work: a unit built inside the house or an existing garage needs no new foundation, while a detached unit does. After the site visit we give you a schedule for your project rather than a general estimate.
It depends on the type and size of the unit, the foundation and utility work, the number of kitchens and bathrooms and the finishes. We give you a written price after the site visit, based on your property and your plans.
| Monday – Thursday | 8:00AM – 7:00PM |
| Friday: | 8:00AM – 2:30PM |
| Saturday: | Closed |
| Sunday: | 8:00AM – 7:00PM |
