Most contractors do remodels. Fewer do additions well. The difference is in the structural, permitting, and design coordination that additions require — areas where shortcuts can cost you years later.
Look for addition experience specifically
Ask how many additions the contractor has built in the last three years. Ask to see one or two of them, ideally finished a couple of years ago so you can see how the work has held up.
Ask about their permit experience in your jurisdiction
Portland, Beaverton, Lake Oswego, Tigard, Clackamas County — each has its own quirks. A contractor who works in your jurisdiction regularly will know what to expect on plan check and inspections.
Talk through the integration with the existing house
Where does the new roof tie into the old roof? How will the siding match? Will the addition share an HVAC system or get its own? Where does the new electrical tie into the existing panel? A good contractor has clear answers; a less-experienced one waves their hand at it.
Get a real timeline
“Three to four months” is not a timeline; it’s a hope. Real timelines have phases, durations, and dependencies. Ask for one.