Home Addition Cost Boise

Homeowners in Boise, Meridian, Eagle, Kuna, Star, Middleton, Nampa, and Caldwell ask us about home addition cost more than almost any other line item on a remodel budget. This article is part of our Boise Cabinet Cost Guide—the definitive hub for Treasure Valley remodeling costs.

Numbers below are planning ranges from design-build consultations, not advertisements. Your home, layout, and finish level will move you within or beyond these bands.

Use our project estimator for a rough range, then request an in-home visit for written scope.

Ground-floor additions often run $80,000–$250,000+ including design, permits, foundation, framing, MEP, and finish. Second stories can exceed this when structural retrofits are required.

Soils, setbacks, and utility locations in Eagle and Hidden Springs affect foundation type. Rock and drainage add site cost in Foothills lots.

Roof lines, siding, and window rhythm must match or intentionally contrast per HOA and city design standards.

ADUs and guest houses overlap addition economics—see ADU services and this guide’s companion articles.

Boise additions, Eagle, Kuna, Nampa area.

Explore our Boise Cabinet Cost Guide, Treasure Valley guide, Boise remodeling guide, service areas, Boise kitchen remodels, Meridian bathrooms, Eagle whole-home, Nampa additions, schedule a consultation, and project estimator.