2 Best ADU Builders in Portland, Maine
Verified ADU contractors and builders in Portland, ME
Showing 1–2 of 2 listings
BrightBuilt Home
BrightBuilt Home is the sister company of Portland firm Kaplan Thompson Architects, pioneers in the design of high-performance homes. They’re all net-zero, producing as much energy as they consume in a year.
O'Brien Wood & Iron
Transform your underutilized garage into functional living space with expert conversion services in the Portland area. Our specialized team handles every aspect of garage-to-living-space conversions, from structural modifications to finishing touches that seamlessly integrate your new room with your home.
Frequently Asked Questions — ADU Builders in Portland
How much does it cost to hire an ADU builder in Portland?
ADU construction costs in Portland, Maine vary widely depending on size, type, and site conditions. Detached ADUs typically range from $150,000–$400,000+, while garage conversions and attached ADUs can be more affordable. Contact multiple builders in Portland to get accurate quotes for your specific project.
How long does it take to build an ADU in Portland?
In Portland, the ADU construction timeline typically ranges from 6 to 18 months from permit application to move-in. Permitting alone can take 2–6 months depending on Maine local regulations. Prefab and modular ADUs often have faster timelines than site-built units.
Do I need a permit to build an ADU in Portland?
Yes, a building permit is required for ADU construction in Portland, Maine. Your ADU builder will typically handle the permit application as part of their service. Maine has adopted streamlined ADU permitting laws in recent years, which may reduce wait times.
What types of ADUs can be built in Portland?
Common ADU types in Portland include detached ADUs (backyard cottages), attached ADUs, garage conversions, basement conversions, and prefab/modular ADUs. The best type for your property depends on lot size, zoning, and budget. A local Portland ADU builder can advise on what's allowed on your specific parcel.