The Real Cost of Underinsurance: Why Your Home Policy Probably Isn’t Enough

Most Ontario homeowners assume their existing policy is “good enough.” It probably was, when they bought it. But construction costs have outpaced general inflation by nearly 40% over the past five years — and most home insurance limits haven’t been adjusted to match. The result is a quiet crisis: thousands of homeowners are technically insured, but functionally underinsured, and they won’t find out until they file a claim.

This article walks through what underinsurance actually means, why your policy is probably out of date, and the three questions you can ask right now to find out where you stand.

What “underinsured” actually means

Underinsurance isn’t about not having a policy. It’s about having a policy whose dwelling limit — the dollar amount it will pay to rebuild your home — is lower than what it would actually cost to rebuild it today. When that gap exists and you have a total loss, you’re left covering the difference yourself.

Here’s the wrinkle most people miss: many Ontario policies include a “co-insurance” clause that reduces partial-loss payouts proportionally if your dwelling limit is too low. So underinsurance doesn’t just hurt you in a worst-case fire — it hurts every claim, including a $40,000 kitchen flood.

Why your policy is probably out of date

Three things have changed since 2019:

• Lumber, drywall, roofing, and labour costs have all risen sharply — in some material categories, more than 50%.
• Building code requirements have changed. Modern reconstruction often requires upgraded electrical, insulation, or accessibility features that weren’t required when your home was built.
• Most insurers apply a small annual inflation adjustment (typically 2-3%) to your dwelling limit at renewal. That hasn’t kept pace with actual construction inflation in 2020-2024.

The cumulative effect is a slow erosion. A policy that was sized correctly five years ago is now likely 15-25% short.

The three questions to ask right now

1. What is my current dwelling limit?

Pull out your most recent policy or declarations page. Find the line labelled Coverage A — Dwelling or Building. Note the dollar amount.

2. What would it cost to rebuild my home today?

This is not the market value, the assessed value, or what you paid for it. It’s the cost to replace the structure from the foundation up — labour, materials, permits, demolition, debris removal, and code-required upgrades.

A reasonable proxy in 2025 Ontario:

• Standard single-family home: $300–$450 per square foot
• Custom or higher-end build: $450–$700+ per square foot
• Older homes with character details (plaster walls, custom millwork): add 15–25%

Multiply by your home’s above-grade square footage. A 2,200 sq ft standard home in Mississauga is realistically $750k–$900k to rebuild today, before any code-upgrade requirements.

3. Does my policy include guaranteed or extended replacement cost?

Many policies have an endorsement that automatically extends your dwelling limit by 25-50% (or, for some carriers, unlimited) if rebuild costs exceed the stated limit. Some carriers include this by default; others charge extra for it. If you don’t have this endorsement, your dwelling limit is your hard ceiling.

What to do about it

1. Request a current rebuild calculation from your broker. Most carriers have proprietary tools that estimate rebuild cost based on your home’s square footage, finishes, and Ontario regional construction data. Ask for it.
2. Add or upgrade replacement cost endorsements. Guaranteed replacement cost (or its close cousin “extended replacement cost”) is one of the highest-value endorsements you can add — usually for less than $100/year.
3. Update your dwelling limit at renewal. If the rebuild calculator shows a higher number than your current limit, ask your broker to adjust. The premium difference is usually modest.
4. Re-check after major renovations. A finished basement, new kitchen, or addition raises your rebuild cost — your limit needs to match.

The bottom line

Underinsurance is one of the easiest insurance problems to fix and one of the most expensive to ignore. A 30-minute review with your broker is enough to either confirm you’re properly covered or identify exactly what to adjust. There’s no scenario where it pays to delay this conversation.

If you’re an Ontario homeowner and want a fresh rebuild calculation done — including which carriers offer guaranteed replacement cost as standard versus as an endorsement — get in touch. I’ll review your current policy and tell you straight whether you’re protected.