ADU Foundation & Site Work in Palo Alto
Excavation, grading, utility trenching, and foundation work sized correctly for your ADU structure.
Getting the Ground Right Before Anything Goes Up
Foundation and site work is where ADU budgets most often get thrown off by surprises — unexpected soil conditions, tight utility access, or drainage issues that were not visible until excavation started. We do a geotechnical review and full utility locate before finalizing your quote, so the number we give you accounts for your actual site, not a generic assumption.
Work includes excavation and grading, the foundation itself (slab, raised, or pier depending on the design and soil), and trenching for water, sewer, gas, and electrical utility connections to the new structure.
- Geotechnical review and utility locate before final pricing
- Excavation, grading, and drainage planning
- Foundation type matched to your soil and structural design
- Utility trenching for water, sewer, gas, and electrical
Frequently Asked Questions
How much does ADU foundation work cost?
Foundation and site work typically runs $25,000 to $60,000+ depending on soil conditions, grading needs, and utility distance from the main house. A geotechnical review lets us quote accurately.
What type of foundation does an ADU need?
Most Palo Alto ADUs use a standard slab or raised foundation depending on the structural design and soil report — our structural engineer specifies the right type for your project.
How far can utilities run to a backyard ADU?
It depends on your lot layout and where existing water, sewer, gas, and electrical service enter your property. We map utility routing during the site evaluation before finalizing your quote.
Do you handle grading and drainage?
Yes — proper grading and drainage around a new ADU foundation is part of every site-work scope to keep water away from both structures.