Attached ADU design and construction in Folsom
An attached ADU is the unit that shares one wall with your house and almost nothing else. Its own entrance, its own kitchen, its own bath — a complete second home that happens to be joined to your first. We build them across Folsom from our Sacramento base about 25 minutes west, and most of this page is the stuff we wish every Folsom homeowner knew before the first phone call: how the shared wall works, what the City of Folsom wants, and where the money actually goes.
Attached or detached on a Folsom lot
The first fork in any ADU conversation is attached versus detached, and on a Folsom lot the answer usually comes down to geometry. An attached ADU grows off your house, sharing one wall. A detached unit stands alone in the backyard. People assume detached is the default, but a lot of Folsom's master-planned tracts put houses close to the side property line with modest yards, and a freestanding cottage needs clear space on every side to satisfy setbacks. Hang the unit off the house and you only have to clear the outer-side setback — often the difference between a project that pencils and one that stalls.
There's a structural trade both directions. Detached buys total independence: no shared wall, no tie-in to your roof, no question of whether your footing can carry a new load. You pay with a second foundation and a second roof, and on Folsom's granite that second foundation isn't cheap. Attached borrows your wall, roofline, and frequently your utilities, which trims the budget — but it asks more of your existing house. If the wall needs work, or the foundation needs a transition over rock, some of that savings goes back into the connection.