A Real Price
Know what your ADU or addition will cost before construction starts.
Add space without moving, with a clear price, a straightforward plan, and a crew that keeps the work moving.
Diamond CertifiedLicensed, bonded and insuredLic# 1113139
A price, not an estimate
One accountable team
5-star rated on Google
A price, not an estimate
What you can expect
Good work matters. So does knowing what is happening, what it costs, and who is accountable for the result.
Know what your ADU or addition will cost before construction starts.
Once construction begins, the crew keeps the work moving, with clear updates if an inspection or curing time calls for a pause.
From design, plans and permits to skilled trades and final details, your project stays coordinated from start to finish.
New space designed to match your home and the way you live, and to add value for years to come.
We do our best work when we design and build the whole project. If you only need drawings or a prefab unit set in place, a specialist will usually serve you better.
Design, permits and construction
Bedrooms, family rooms, kitchenettes and living space, planned with our architect partner, permitted and built by one accountable team.
Covered room · fireplace
Open shelves · beverage fridge
Vaulted ceiling · glass doors
Fireplace · tall windows
Built-ins · wide window
The Dynamite difference
Most building estimates leave room for the bill to grow. We give you a clear price for the project we agree on, from foundation to finish.
Dynamite Construction has earned the prestigious Diamond Certified award.
Diamond Certified
Any contractor can promise quality. Diamond Certified checks it. Their researchers survey a company’s real customers by phone, and only companies that score 90 or higher out of 100 for quality and helpful expertise earn the award. They also verify the company’s license, insurance and complaint record.
5.0Average rating from 10 verified customer surveys
90+Score out of 100 needed to qualify
Since 2025Diamond Certified
A clear, simple process
You do not need plans before you call. We help you work through design, permits and budget in the right order.
Tell us what you want to add and when you would like to build. We will talk honestly about cost and fit before anyone drives anywhere.
We visit, look at the space, access and utilities with you, and map out design, permits and budget. Once plans are ready, you get a firm price before construction starts.
Once work starts, the crew keeps moving. You get clear communication and one accountable team through the final walkthrough.
About Dynamite Construction
Dynamite Construction is a family-owned Bay Area remodeling company built on a passion for creating homes where people can thrive. For more than 10 years, the team has brought practical planning, skilled craftsmanship, and personal attention to every project.
Licensed, bonded, and insured, they have built their reputation on straight answers, quality work, and following through on what they promise.
10+Years of experience
5-StarHomeowner reputation
1113139California license
Where we work
Our reputation speaks for itself
Real projects, real homeowners, and a consistent record of care, communication, and craftsmanship.
★★★★★
★★★★★
“We expected a lot of headaches, delays and unexpected charges. With Spencer and his team none of that happened.”
Vlad S. · San Francisco
“You guys did a great job at my uncle’s house. The ADU is awesome!”
Nery M. · ADU
“Great final deck product from the dynamite team. They executed a complex set of plans and we are happy with the result.”
Maggie M. · Custom deck
Questions before you build
A good project starts with clear expectations. These are the questions homeowners ask us most often.
ADUs and additions start at around $250,000. Every project is different, so we map out the budget with you at the first visit, and you get a firm price once the plans are ready.
Yes. Once the plans and scope are set, that is your price, and it covers the common surprises in older homes, like dry rot or water damage from a small leak. If we find something bigger, like a structural problem or a change the inspector asks for, we will show you what we found and agree on the next step together before work goes on.
Yes. We work with our architect partner on the design and plans, handle the permits, and manage the plumbing, electrical and construction, so you have one team from plans to finish.
Yes. At the first visit we look at the structure, the foundation and the utilities with you, and talk through what it will take to turn your garage into a comfortable, permitted living space.
Yes. We design additions to match your home’s style, rooflines and finishes, so the new space looks like it was always there.
It depends on the design, the permit process and the size of the project, and we walk you through the full schedule, including plans and permits, before work begins. Once construction starts, the crew keeps the work moving and you get clear updates along the way.
Anyone who will help make decisions about the project. Design choices can move the price significantly, so having everyone there helps us plan the right project and budget from the start.
Marin County, Napa, Sonoma and Petaluma in the North Bay, San Francisco, and the East Bay, including Oakland, Berkeley, Alameda and Piedmont.
Start your ADU or addition
Tell us what you have in mind. We will talk through the scope and timing, and then set a time to walk your property in person.
Call (650) 455-1557
Serving Marin, Napa, Sonoma, San Francisco and the East Bay
