With Bay Area housing prices where they are, adding square footage almost always beats moving. The question we hear every week in Vallejo: should it be an addition or an ADU?
An addition expands your existing living space — ideal when your family needs another bedroom, a bigger kitchen, or a home office and you want it all under one roof. Additions typically cost less per square foot than a standalone structure because they share your home’s foundation, roofline, and utilities.
An ADU (accessory dwelling unit) is a separate, self-contained home on your lot — a backyard cottage, garage conversion, or attached unit with its own entrance, kitchen, and bath. California law has made ADUs dramatically easier to permit, and they shine when the goal is rental income, housing for aging parents, or long-term property value. Garage conversions are usually the most budget-friendly path, often starting around $120,000 in our area, while new-build detached ADUs commonly run $250,000 and up.
The right answer comes down to your lot, your budget, and what the space needs to do in ten years — and that’s a conversation best had standing in your actual backyard. Book an ADU & Addition Planning Session and we’ll bring the permit knowledge; you bring the ideas.