Home insurance and renovations: What to tell your insurer

Written by Samantha SheltonNMLS 1647301Updated October 2026

A renovation changes what it would cost to rebuild your home, and that number, not your purchase price and not your market value, is what your dwelling coverage is supposed to match. Most homeowners policies pay a partial loss in full only when your dwelling limit sits at or above roughly 80% of replacement cost, so a finished basement or a 400-square-foot addition your insurer never heard about can quietly push you below the line.

Homeowner on the phone in a half-finished kitchen addition discussing home insurance and renovations coverage

The traffic runs both directions. Projects that add square footage or upgrade finishes raise your rebuild cost and usually your premium. Safety work often cuts it: the Insurance Information Institute (Triple-I) says you can usually get discounts of at least 5% for a smoke detector, burglar alarm, or dead-bolt locks, and that some carriers cut premiums by as much as 15% or 20% for a sophisticated sprinkler system paired with a fire and burglar alarm that rings at a monitoring station.

So make two calls, not one: before demolition day, and again when the work is done. Learn how renovations change your home insurance, including which coverages a project touches, which upgrades move the premium, and how to verify your contractor’s coverage first. For wider context, see our Homeownership guide and the Insurance & Protection hub.

Key takeaways:

Coverage follows rebuild cost: Additions, finished basements, and higher-end finishes raise what it costs to rebuild, and most policies pay a partial loss in full only when your dwelling limit is at least about 80% of replacement cost.
Some projects cut the premium: Discounts of at least 5% are common for smoke detectors, burglar alarms, and dead-bolt locks, and some carriers go as high as 15% or 20% for a sophisticated sprinkler system plus a monitored fire and burglar alarm.
Make two calls, not one: Notify your insurer before work starts and again at completion, and confirm your contractor’s general liability and workers compensation coverage first. Detached structures like a new pool house are generally covered at only about 10% of your dwelling limit.

Why do renovations change your home insurance?

Because dwelling coverage is set against replacement cost, what it would take to rebuild the house with materials of like kind and quality, and a renovation moves that number. Market value doesn’t drive it. Neither does what you paid. A 1,600-square-foot ranch with builder-grade finishes and that same house after a kitchen gut and a primary-suite addition are two different rebuild jobs, even on the same lot.

The Insurance Information Institute’s guideline for the structure is one sentence long: purchase enough coverage to rebuild your home. A new deck, a second bathroom, or a larger kitchen all move that number, and a limit set before the work is a limit set against the old house. Two features help you hold the line: an extended replacement cost endorsement, which Triple-I says can pay an extra 5% to 25% above your limits, and an inflation guard clause, which automatically adjusts the dwelling limit to reflect current construction costs in your area when you renew.

Neither one knows about your addition. Inflation guard follows the price of materials and labor. It does not follow the 400 square feet you added last spring. That part is your phone call.

Here’s the shape of the risk. Suppose your policy still describes a 1,600-square-foot home, but you’ve since finished the basement and added a bedroom, putting real rebuild cost at $400,000 while your dwelling limit still reads $300,000, 75% of what the rebuild now costs. A kitchen fire does $60,000 in damage. Because your limit fell below the roughly 80% threshold most policies use, the carrier applies a proportional reduction instead of writing the full repair check, and you fund the difference.¹

So re-read your declarations page before the next project. Our guide to evaluating home insurance options covers comparing limits across carriers, and homeowners insurance deductibles explains why the one you picked when the house was smaller may need a second look. The Insurance Information Institute’s guide to how much homeowners insurance you need is a useful second read.

Which parts of your policy a renovation actually touches

Five coverages move when you renovate, and only the first one is obvious. Ask your agent to reprice all five in one conversation.

Dwelling coverage: The limit that rebuilds the structure. Every square foot you add and every finish you upgrade belongs here, including work that converts unfinished space, a basement finish, an attic buildout, or converting a garage into living space.
Other structures: Detached buildings such as a garage, tool shed, or gazebo are generally covered for about 10% of the insurance on the house itself. A studio, a pool house, or a long run of new fencing passes that sublimit fast, which is when you buy increased other-structures limits.
Personal property: Generally 50% to 70% of your dwelling coverage. A remodel that arrives with new appliances and built-ins raises what’s inside the walls too.
Loss of use: Additional living expenses generally run about 20% of the insurance on your home, what pays for somewhere to live if a covered loss makes the house uninhabitable, and a bigger house takes longer to rebuild.
Personal liability: Limits generally start at about $100,000. A pool changes that math: it is the classic attractive nuisance, and the Insurance Information Institute already recommends homeowners consider carrying at least $300,000 to $500,000 in liability coverage, and more if your property, investments and savings are worth more than the limit. Our guide to buying a home with a pool covers the rest of the ownership costs.

One gap a renovation cannot close is flood. A standard homeowners policy will not pay for damage caused by a flood, an earthquake, or routine wear and tear, and a newly finished basement is precisely the room that floods. Flood coverage is a separate policy, written through the National Flood Insurance Program or a private carrier, and FEMA’s timing rule matters: an NFIP policy generally takes effect 30 days after purchase, with narrow exceptions such as buying it in connection with making, increasing, extending, or renewing a mortgage. Even then, a basement gets limited protection: FEMA’s fact sheet on what flood insurance covers in a basement lists equipment such as furnaces, water heaters and sump pumps, plus cleanup, and excludes basement improvements such as finished flooring, finished walls and built-ins. Ask your agent what would cover a finished lower level before the carpet goes down.

Which renovations raise your premium and which lower it

Verdict first: anything that makes the house bigger or costlier to rebuild pushes the premium up; anything that makes a fire, burst pipe, or break-in less likely pushes it down. Most projects do both, so price them together.

Renovation	Effect on premium	Why
Room addition or added square footage	Up	Bigger footprint, higher rebuild cost, higher dwelling limit
Finished basement	Up	Turns unfinished space into finished rebuild cost and adds contents below grade, where flood stays excluded
Kitchen or bath remodel with higher-end finishes	Up	Stone, custom cabinetry, and premium fixtures cost more to replace like for like
In-ground pool	Up	Attractive-nuisance liability, plus pressure on your other-structures limit
Deck, patio, or detached garage	Up, usually modestly	Adds insurable structure value and some liability exposure
New roof or stronger roofing materials	Often down	Triple-I lists reinforcing your roof and stronger roofing materials among the ways to lower premiums
Replacing knob-and-tube or aluminum branch wiring	Often down	Removes a fire-risk factor carriers surcharge or decline over
Replacing aging supply plumbing	Often down	Cuts the odds of the burst-line and slow-leak losses carriers price for
Monitored alarm or sprinkler system	Down	At least 5% is typical for basic devices; as much as 15% or 20% for a sophisticated sprinkler plus a monitored fire and burglar alarm

Age is its own rating factor. Triple-I notes coverage may be cheaper when a home’s electrical, heating, and plumbing systems are less than 10 years old, and recommends modernizing them to reduce fire and water damage risk. Replacing a 40-year-old panel isn’t glamorous, but it moves an underwriting variable a quartz countertop does not.

Wiring deserves its own paragraph. The Consumer Product Safety Commission has documented home fires attributed to aluminum branch-circuit wiring, common in homes wired between roughly 1965 and the mid-1970s, and publishes repair guidance for it. Carriers know that history: some surcharge homes with active knob-and-tube or aluminum branch wiring, and some decline them outright. Rewiring is one of the few renovations that improves insurability and lowers the premium at once.

A premium discount is rarely a reason to do a project on its own. Weigh the work on daily use and resale.

What to do before, during, and after a renovation

Four steps before demolition day, three while the work runs, and four at the finish.

Before work starts

Get the real number: Ask your contractor for a written scope and cost estimate, then hand it to your agent. What the finished house costs to rebuild beats a guess at what it will appraise for.
Ask about builders risk: Builders risk policies are written for property under construction, renovation, or remodeling, and typically cover materials on site, theft, vandalism, and construction damage a homeowners policy isn’t designed to handle. Ask whether your project needs one or whether an endorsement will do.
Ask the vacancy question: If you’re moving out during the work, ask in writing how your policy treats a vacant or unoccupied dwelling. Many standard forms suspend certain coverages once a home has been vacant beyond a set number of consecutive days, commonly 60, though the provision usually reads differently for a home genuinely under construction.²
Pull the permits: Unpermitted work creates problems at claim time and again at resale. Our guide to home renovation permits covers which projects trigger one.

While the work is underway

Document everything: Photograph each stage and keep receipts, change orders, and the contract. That paperwork turns a claim conversation into arithmetic.
Track scope changes: A bathroom refresh that grows into a dormer is a different rebuild cost. Call your agent when scope changes, not when the job ends.
Watch for water: Open walls, disconnected drains, and stalled projects are how small leaks become expensive ones.

When the project is finished

Send the final numbers: Give your agent the as-built square footage and final cost, and ask them to reset the dwelling limit against current replacement cost.
Ask for a discount review: Name every safety item you installed, alarms, sprinklers, detectors, dead bolts, roofing, wiring, plumbing, and ask which ones your carrier credits.
Get it in writing: A verbal confirmation is not coverage. Read the new declarations page and confirm the sublimits moved.
Put it on a cycle: Add a policy review to your home maintenance calendar so limits keep pace.

How to verify your contractor’s insurance

Ask for two coverages and one document. The coverages are commercial general liability, which responds when the contractor damages your property, and workers compensation, which responds when someone is hurt on your job. The document is a certificate of insurance, standard form ACORD 25.

Be the certificate holder: Ask that it be issued to you by name and address and sent by the contractor’s agent, not forwarded by the contractor.
Call the insurer, not the contractor: Use the carrier or agency number printed on the certificate to confirm the policy is in force. A certificate is a snapshot, not a guarantee.
Read the dates and limits: Confirm the effective and expiration dates cover your whole schedule.
Confirm who’s on site: Ask whether subcontractors carry their own coverage or ride on the contractor’s policy.

Weighing a contractor against doing parts of the job yourself? The insurance answer usually favors the licensed pro, our look at DIY home renovation projects covers where the line sits. For scope and contract basics, the National Association of Home Builders consumer resources, which include a remodeling section, are a fair starting point, and financing home renovations covers how to pay for it.

Three mistakes that leave homeowners underinsured

Telling the insurer afterward: Calling at completion beats never calling, but it skips the builders risk and vacancy questions, the two that only matter while the work is happening.
Raising the dwelling limit and stopping: Other structures, personal property, and loss of use are typically percentages of that limit, but sublimits and endorsements still need checking against what you built.
Skipping the discount review: Homeowners install qualifying safety equipment and never mention it. The credit isn’t automatic and nobody at the carrier is watching your job site, the same principle behind claiming incentives when renovating for energy efficiency.

How Align handles insurance and taxes in your payment

Insurance is part of your monthly cost whether it is escrowed or not, so Samantha prices the full payment before you commit, not just principal and interest.

She also builds in Michigan's tax uncapping. The year after a Michigan home sells, its taxable value resets to half of the assessor's market value, so the seller's tax bill is not your tax bill. She quotes your number, not theirs.

Get a homebuying budget review

Sources: Michigan Treasury, transfer of ownership and uncapping.

FAQ: Home insurance and renovations

Here are answers to common questions about home insurance and renovations.

Do I need to tell my insurance company about a renovation?

Yes, and before work starts. Your insurer may require a builders risk policy during major construction, needs to know if the home will be vacant, and has to reset your dwelling limit when the project changes your cost to rebuild. Waiting until a claim to sort this out is how homeowners discover they’re covered for the house they used to have. Fold the call into the planning stage alongside the rest of your home improvement and design checklist.

Will my premium go up after a renovation?

Not always. Additions, finished basements, and premium finishes raise replacement cost and usually raise the premium. But re-roofing, replacing old knob-and-tube or aluminum wiring, updating galvanized plumbing, and adding monitored alarms or sprinklers can reduce risk enough to offset or beat the increase. Ask your agent to price both effects together.

What happens if I do not update my insurance after remodeling?

You risk being underinsured. If the policy still reflects a 1,600-square-foot home with builder-grade finishes and you now have 2,000 square feet with a custom kitchen, a total-loss claim pays toward the old figure. Some policies also reduce partial-loss payouts when coverage falls below a required percentage of replacement cost. Note that this is a rebuild-cost question, not the market-value question answered by the home appraisal process.

Does homeowners insurance cover damage during a renovation?

Sometimes, but not reliably. Standard policies are written for occupied, finished homes, and major projects often need a builders risk policy or a renovation endorsement covering materials on site, theft, and construction-related damage. Your contractor’s liability policy covers their negligence, not every loss. Confirm in writing who covers what before demolition day, and expect the question to come up early if you’re taking on the kind of gut job described in our guide to the advantages of buying a fixer-upper.

The bottom line on home insurance and renovations

Renovations change your cost to rebuild, and your dwelling coverage has to follow. Most policies pay a partial loss in full only when your dwelling limit is at least about 80% of replacement cost, so the addition or finished basement your insurer never heard about is the one that costs you at claim time. Call before demolition to settle the builders risk and vacancy questions, verify your contractor’s general liability and workers compensation coverage, then call again at completion with as-built square footage, final costs, and every safety upgrade. Discounts start around 5% and reach 15% or 20% for a monitored sprinkler and alarm setup.

If you’re ready to take on a project bigger than cash on hand covers, talk to Align Lending. We’ll shop your renovation or cash-out scenario across our lender network and show you the options side by side. Call 248-506-5727 or start online.

Footnotes:

1. The roughly 80% figure is an insurance-to-value (coinsurance) threshold used in most, but not all, homeowners policy forms; the exact percentage, the reduction formula, and whether the provision applies at all are set by your policy language and your state’s regulations. The $400,000 replacement cost, $300,000 dwelling limit, and $60,000 loss are illustrative figures chosen to show how the arithmetic works. They are not a quote, an estimate for any specific property, or a prediction of how any carrier would settle a claim. Read your declarations page and policy form, and ask your agent to confirm in writing how your coverage responds to a partial loss. Return to text.

2. Vacancy and occupancy provisions vary meaningfully by policy form, carrier, and state. Many widely used homeowners forms suspend coverage for certain perils once a dwelling has been vacant beyond a stated number of consecutive days, commonly 60, and the definitions of “vacant,” “unoccupied,” and “under construction” are not interchangeable. A home undergoing renovation that precludes normal occupancy is often treated differently from an empty one. Because the outcome turns on specific policy wording, ask your insurer to confirm your situation in writing rather than relying on a general rule. Return to text.

Sources: dwelling, other structures (about 10% of the dwelling amount), personal possessions (generally 50% to 70%), liability limits generally starting at about $100,000, and the exclusion of flood, earthquake, and routine wear and tear from standard homeowners policies. Insurance Information Institute, “What is covered by standard homeowners insurance?” Additional living expenses of about 20% of the insurance on the house, the recommendation to consider at least $300,000 to $500,000 in liability coverage, the guideline to purchase enough coverage to rebuild your home, extended replacement cost of an extra 5% to 25% above policy limits, and inflation guard clauses. Insurance Information Institute, “How much homeowners insurance do I need?” Discounts of at least 5% for a smoke detector, burglar alarm, or dead-bolt locks; as much as 15% or 20% for a sophisticated sprinkler system plus a monitored fire and burglar alarm; guidance on modernizing heating, plumbing, and electrical systems, on systems less than 10 years old, and on reinforcing a roof or buying stronger roofing materials. Insurance Information Institute, “12 Ways to Lower Your Homeowners Insurance Costs.” The 30-day NFIP waiting period and its mortgage-related exception, and the fact that most standard homeowners policies do not cover flood damage. FEMA, National Flood Insurance Program. Basement building items, cleanup coverage, and the exclusion of basement improvements, FEMA, “What Does Flood Insurance Cover in a Basement?” (January 2022). Home fires attributed to aluminum branch-circuit wiring and repair guidance for homeowners, U.S. Consumer Product Safety Commission, “Repairing Aluminum Wiring” (Publication 516).

This article is for informational purposes only and is not intended to provide legal, financial, insurance, or tax advice. Coverage terms, sublimits, discounts, exclusions, and availability are set by individual insurance carriers and vary by policy form and state, consult your insurance agent or a qualified professional about your situation before relying on anything here. Align Lending does not sell insurance and is an independent Michigan mortgage broker, NMLS #2041154, not acting on behalf of, endorsed by, or sponsored by FEMA, the National Flood Insurance Program, the Consumer Product Safety Commission, or any government agency.