ADU cost calculator
Real starting prices for construction, based on size and bathrooms. Pick any size or one of our 17 plans.
- 9-foot ceilings
- Plywood-box cabinets
- Quartz countertops
- Fully tiled bathrooms
- Concealed mini-split HVAC
Included as standard in every price.
What's included
Every starting price includes construction of the ADU with Core's standard finishes:
- 9-foot ceilings. Every plan, every room, at no extra cost. Taller windows and doors to match.
- Plywood-box cabinets. Real wood cabinet boxes and doors. No particleboard.
- Quartz countertops. In the kitchen and bathrooms.
- Fully tiled bathrooms. Tiled showers and floors, not acrylic surrounds.
- Concealed mini-split HVAC. Built-in, ducted heating and cooling. No wall-mounted units.
- Full construction. Foundation, framing, roofing, windows and doors, electrical, plumbing, insulation, drywall, flooring and paint.
Quoted for your site
These costs depend on your property and your city, so we price them after a free site visit rather than guess:
- Plans and engineering. Architectural drawings, structural engineering and energy calculations.
- Permits and agency fees. Set by your city or county. ADUs under 750 sq ft pay no impact fees under California law.
- Utility connections. Water, sewer, electrical and gas, which depend on distance and what's already on site.
- Upgrades. Anything beyond our standard finishes.
How we price
Starting prices follow one simple rule, so there are no surprises between plans: a base cost that every ADU carries (kitchen, bathroom, mechanical systems), plus a cost per square foot, plus an amount for each additional bathroom. Bigger ADUs cost more in total but less per square foot.
Ready to see what fits your lot?
Book a free site visit. We’ll check what your property allows and give you a full estimate, including plans, permits and utility connections.