Garage Conversion Contractor in Sonoma County
Garage Conversions. Designed, Permitted, Built.
Northern Hills Construction converts underused garages into comfortable, permitted living space across Sonoma County - ADUs, in-law units, guest suites, and home offices. As a licensed general contractor based in Guerneville, our father-son team manages the entire conversion for you: feasibility, design, permitting, and construction. One crew and one point of contact, from the first sketch to the final inspection.
How We Convert Your Garage
Common Questions
Can I turn my garage into an ADU? In most cases, yes - California law allows ADUs on most residential lots, and converting space you already have is often the simplest path. Will I lose my parking? When a garage is converted to an ADU, state law says your city or county can't require you to replace the covered parking. Do conversions need permits? Yes - and we prepare, submit, and manage the whole permit process on your behalf.
Our proven 3-step method for planning, permitting, and building your garage conversion.
1. Feasibility & Layout
Every conversion starts with the garage itself: structure, slab, ceiling height, access, and utilities. We walk the property, confirm what your local standards allow, and design a layout that makes the new space live like a natural part of your home.
2. Permits, Handled
We prepare the plans, submit them, and manage the review with your local building department. ADU approvals are ministerial in California - no discretionary hearings - and because the structure already exists, a garage conversion usually keeps its current footprint with no new setback requirements.
3. Build With Confidence
Our own crew builds the conversion with the same craftsmanship as our custom homes. We schedule every inspection and hand over a finished, code-compliant space ready to use.
From full ADU conversions to guest suites and home offices, we turn existing garage space into comfortable, code-compliant rooms. Here is how we can put your garage to work.
ADU Garage Conversions
Convert the garage into a legal accessory dwelling unit - a rental, guest house, or space for family. We handle the structural work, insulation, windows, utilities, and finishes, and manage the permit process start to finish.
In-Law Units & Guest Suites
Turn the garage into comfortable space for aging parents, adult children, or long-term guests. We design the layout around access, privacy, and your existing utilities.
Home Offices & Flex Space
Need workspace, a gym, or a playroom? A permitted garage conversion adds usable square footage without building an addition - we handle insulation, heating, electrical, and finishes.