Why your existing policy is probably not enough
A standard California homeowners policy was written for one main house and one family. When you add an ADU — especially a rented ADU — you change the risk profile in ways your insurer needs to know about.
What changes when you add an ADU
- Total insured value goes up (the new structure adds replacement cost).
- Liability exposure changes if a tenant is on the property.
- Use of property shifts from purely residential to partially income-producing.
- Loss of use coverage may need to account for two dwellings, not one.
Coverage to add or confirm
Replacement cost coverage
Increase the policy's dwelling coverage to include the ADU at full replacement cost — not just market value.
Loss of rent / fair rental value
If you rent the ADU, add coverage that pays you the lost rent if a covered event makes the ADU uninhabitable.
Landlord liability
Standard homeowners liability may not cover incidents involving paying tenants. A landlord liability endorsement or a separate dwelling-fire (DP-3) policy may be needed.
Tenant-caused damage
Most homeowners policies exclude tenant-caused damage. Landlord-specific coverage usually fills this gap.
Wildfire and earthquake
Standard policies exclude earthquake; California Earthquake Authority coverage is separate. Wildfire is covered by most policies but premiums are climbing fast. Confirm both before construction.
Three questions to ask your insurer before you build
- "I am adding a 1,000 square foot ADU that I plan to rent long term. Does my current policy cover this, or do I need an endorsement or separate policy?"
- "If a tenant slips and falls, am I covered?"
- "What documentation do you need from my contractor during construction?"
Get every answer in writing.
During construction
You also need a course-of-construction policy (sometimes called "builder's risk") during the build itself. Your builder may carry this, or you may need your own. Confirm which one applies before framing starts.
Related reading
Frequently asked questions
Do I need a separate insurance policy for my ADU? Not necessarily — many insurers can endorse your existing policy. Others prefer a separate landlord policy.
Does my insurance change if family lives in the ADU vs a paying tenant? Yes — paying tenants typically trigger landlord-style coverage requirements.
When should I update my policy? Before construction starts, and again before the first tenant moves in.