Additions — Home Addition Contractor — Modesto & the Central Valley
An addition that looks like an addition is a failure. We design additions to match the original house in roofline, eave depth, window proportion, and siding alignment — from the street, you shouldn't be able to tell where the original ends and the new construction begins.
Getting there is structural work as much as design work: engineering the connection, verifying the existing foundation and systems can carry the new load, and opening walls you can't un-open. It's exactly the kind of project where you want your designer, engineer coordination, and build crew inside one contract — when the wall comes off and the 1960s framing has opinions, the people who drew the plan are the same people standing in the room.
How much does a home addition cost in the Central Valley?
At KHB's standard, a bump-out under 200 square feet runs $85,000–$180,000, a great-room or primary-suite addition $200,000–$450,000, and a second-story addition $400,000–$900,000 or more. The biggest variables are foundation capacity, structural engineering, and code upgrades the addition triggers elsewhere in the house.
Does an addition need a permit in Stanislaus County?
Yes — every addition needs a building permit, structural engineering, and inspections. Permit and plan-check timelines vary by jurisdiction across the Central Valley. In our design-build process, permitting is handled inside the same contract as design and construction, so nothing stalls between hand-offs.
Tell us about the project.
We typically respond within one business day.