ADU vs. Home Addition: Which Is Right for You?
By Eric Dexter, Owner & Builder ·
When you need more space, there are two very different paths: add on to your existing house, or build a separate accessory dwelling unit. They solve different problems — here's how to tell which fits your goals.
What's a home addition?
An addition expands your existing home — a bump-out, a new room, or a second story. It ties into the house's structure, roof and systems, so the new space is part of your home, not a separate unit.
What's an ADU?
An ADU (or detached DADU) is an independent second home on your lot, with its own kitchen, bath and entrance. It adds a whole separate dwelling — not just more square footage.
Cost
A simple addition can cost less than a detached build, but tying new space into an existing foundation, roof and framing adds complexity that narrows the gap. A DADU is a full new-build budget. Price either with the cost calculator and see the breakdown on our realistic costs page.
Added value & rental income — the big difference
This is where they split. An addition makes your home bigger and more comfortable, but it doesn't create a rentable unit. An ADU adds an income-producing home you can rent out — a separate stream of value. If return on investment matters, see is an ADU a good investment?
Privacy & use
An addition keeps everything under one roof and one household. An ADU gives family, tenants or guests their own private space — which is why it's the choice for multigenerational living or rentals.
Which is right for you?
Choose an addition if you simply need more room in your own home. Choose an ADU if you want a private, independent unit — for income, family or flexibility. Not sure? Talk to us and we'll walk both for your property.
