A home addition is one of the largest investments you'll make, and protecting that project—both before and after completion—requires the right insurance strategy. Without proper coverage, you could face tens of thousands in uninsured losses if something goes wrong during construction or if the new structure isn't adequately covered afterward. This guide breaks down exactly what insurance you need at each stage of your addition project.
Builder's Risk Insurance During Construction
Before your contractor pours the foundation, builder's risk insurance should be in place. This temporary policy covers the structure under construction, materials on-site, and labor costs if damage occurs before the project is complete. Most additions take 3–6 months to finish, and weather, theft, or accidents can happen during that window.
Builder's risk typically costs 0.5–1.5% of the total project cost annually. For a $75,000 addition, expect $375–$1,125 in coverage for the duration of construction. The policy usually covers weather damage, theft, vandalism, and fire—but read the fine print for exclusions like ground collapse or settling.
Your contractor often carries builder's risk as part of their project cost, but verify this in your contract before signing. Request proof of coverage and ensure the policy limits match your addition's budgeted value.
Updating Your Homeowner's Policy
Once construction is complete, your standard homeowner's insurance likely won't automatically cover your new square footage. You'll need to increase your dwelling coverage to reflect the added value.
A typical home addition increases property value by 70–80% of the construction cost. A $60,000 addition might add $42,000–$48,000 to your home's insurable value. Contact your insurer and provide them with:
- Final construction drawings or blueprints
- Contractor's completion certificate
- Permit sign-off from your local building department
Most insurers will adjust your policy within 7–10 days. Premium increases are usually modest—roughly $15–$30 per year for every $10,000 in added dwelling coverage—but this varies by location and your insurer's rates.
Liability Coverage for the Addition
Your homeowner's policy's liability section protects you if someone is injured in your new addition. However, verify your limits are adequate. Standard policies often include $100,000–$300,000 in liability coverage, which may be insufficient if a guest is seriously injured in a new kitchen or bedroom.
Consider increasing liability coverage to $300,000–$500,000, especially if you plan to frequently entertain or rent out any part of the addition. This costs roughly $50–$100 extra per year for the bump up.
Specific Risks for Room Additions
Different addition types carry unique risks:
- Kitchen additions: Increased cooking and electrical load. Ensure your policy covers appliance-related damage and verify your electrical system can handle the load before construction begins.
- Bathroom additions: Plumbing leaks are common in newly constructed bathrooms. Some insurers offer endorsements for water damage coverage; cost varies but typically runs $25–$75 annually.
- Bedroom additions: Standard coverage usually applies, but confirm the addition meets local building codes—non-compliant work may void coverage.
- Sunrooms or three-season rooms: These may be classified differently than conditioned living space. Clarify with your insurer whether it's covered as a room or as a structure with limited protection.
Before Hiring a Contractor
Require proof that your contractor carries general liability insurance (typically $1–$2 million per project) and workers' compensation insurance if they employ staff. Request a certificate of insurance listing your address as the "additional insured"—this protects you if a worker is injured and their claim extends to you.
When comparing contractors through platforms like Mercoly, which helps you find and compare trusted home addition providers in one place, always cross-check their insurance credentials independently.
Documenting Your Completed Addition
After the addition is done, photograph and document all new construction, finishes, and built-in features. This record helps you justify your coverage increase to your insurer and speeds up claims if damage occurs later. Keep all invoices and final permits on file for at least three years.
Frequently Asked Questions
Q: Will my homeowner's insurance cover construction damage if the contractor doesn't have builder's risk? No—you'd be responsible for losses. Always require your contractor to carry active builder's risk before breaking ground, and never pay the full balance until the policy is transferred or expires.
Q: Do I need separate insurance for a second-story addition? Your existing homeowner's policy should cover it once completed, but you'll need the builder's risk during construction and must increase your dwelling coverage afterward; second-story additions carry no extra insurance requirement beyond the value increase.
Q: What happens if my addition doesn't meet building codes? Your insurer could deny claims or cancel the policy if they discover code violations; always obtain permits and have final inspections signed off before the addition is considered complete.
Get quotes from trusted contractors today—compare coverage requirements and insurance needs alongside pricing to protect your investment from day one.