I bought a trailer and $15,000 of lumber. I parked it in my driveway and started framing on weekends. One night, a pile of oily rags ignited, and the half-built frame burned to the trailer deck. I called my Homeowner’s insurance. “We cover your house,” they said. “We don’t cover a construction project on a trailer.” I lost the materials and the trailer value.
Key Takeaways
- Homeowners Exclusions: Standard home policies often exclude “motor vehicles” (the trailer) and construction materials for a separate structure unless specifically endorsed.
- Course of Construction (COC): Also known as Builders Risk, this is the specific policy you need. It covers the materials (lumber, windows) and the structure while it is being built.
- The “Secure Site” Rule: COC policies often require the site to be fenced or the materials to be locked up to prevent theft.
- Transition to Permanent: Once the build is done, the COC policy expires. You must switch to a Tiny Home/RV policy immediately.
The “Why” (The Trap)
The trap is “Insurable Interest & State of Completion.”
An unfinished frame is a high liability risk (kids playing on it, collapse) and a high fire risk (sawdust, chemicals). Standard policies hate this.
Builders Risk insurance is designed for this exact period. It covers theft of materials (someone steals your copper wire) and damage to the work in progress.
The Investigation (My Analysis of Options)
Where do you get coverage for a half-built house?
Zurich / US Assure (Builders Risk)
- The Product: They sell standalone Builders Risk policies.
- The Catch: They are used to houses on foundations. You have to explain it’s a “Tiny Home on Chassis.” Some agents will write it; others get confused by the wheels.
Strategic Insurance (TinyHomePolicy.com)
- The Specialist: They offer a “DIY Builder” policy.
- The Coverage: Covers the shell and materials.
- The Requirement: You usually have to show a timeline (e.g., “Build will be done in 12 months”).
The Trailer Policy
- The Base: Insure the trailer chassis immediately with an auto/trailer policy for theft/collision. This covers the frame but not the house you build on top of it unless you update the value monthly.
[IMAGE: Photo of a charred wooden frame on a trailer chassis in a driveway]
Comparison Table
| Feature | Homeowners Policy | Builders Risk (COC) | Auto/Trailer Policy |
| Covers Lumber Pile? | Maybe (limited) | Yes | No |
| Covers Half-Built Frame? | Unlikely | Yes | No |
| Covers Trailer Theft? | No | No | Yes |
| Duration | Annual | 6-12 Months | Annual |
Step-by-Step Action Plan
- Insure the Trailer First: Before you buy lumber, insure the trailer chassis for theft. Cost: ~$100/year.
- Get a Builders Risk Quote: Call a broker. Ask for “Course of Construction” coverage for a tiny home. Estimate the final value (e.g., $50k).
- Keep Receipts Scanned: If your pile of windows is stolen, you need proof of purchase.
- Secure the Site: Put up a “No Trespassing” sign and a motion sensor light. Liability claims (neighbor kid gets hurt on your saw) are the biggest financial threat during a build.
FAQ
Can I live in it while building?
Builders Risk usually excludes “Occupancy.” If you move in, the policy might void. You need a different policy once you sleep there.
Does this cover my tools?
Builders Risk covers materials. It might not cover your tools (drill, saw). Your Homeowners “Personal Property” should cover tools, but check the off-premises limit.
What if the build takes 3 years?
You can usually renew the policy, but the rate might go up. They want you to finish.