Love’s Labor Costs: load-bearing advice for your love-hate relationship with your home.
Dear Dylan,
We want to add about 700 square feet. Every contractor I call says “it depends.” Depends on WHAT? I just want a price per square foot so I can stop lying awake doing math.
Signed, Ballpark Betty in Campbell
Dear Betty,
I’m going to be the hundredth contractor to disappoint you, but I’ll at least tell you why. An addition almost never touches just the new space. Add 700 square feet to a 1,400 square foot house and you’re also tying into the roof, the structure, the electrical, the plumbing, the HVAC and the finishes in the old part. Two additions the same size can cost wildly different amounts: front additions cost more than back ones, second stories are their own animal, and adding on two sides doubles the tie-ins.
What I can tell you: design and plans usually run about $12 to $18 per square foot of the new floor plan, architectural and structural together.
The honest way to get a real number is to have a GC walk your house. Then you can sleep. Promise.
— Your friendly neighborhood contractor
Read more: How much does a home addition cost? in our Home Additions FAQ.
Love’s Labor Costs is written by Dylan Bertet, owner of Build Better Properties, a Bay Area design-build contractor (CSLB #1077286). Letters are made up for fun; the answers are real. Got a question? Send it in, and it might end up in the column.