Risks
Underinsurance
Underinsurance is a sum insured that cannot rebuild or replace what you named. After a partial loss, some wordings also reduce the payout by the proportion you were underinsured. Compare home and contents quotes only after the rebuild or replacement figure is a deliberate number, not a quote-form default.
- Failure mode
- The limit is too small for the event you named
- Partial loss
- Some wordings apply average / co-insurance
- Inputs
- Rebuild cost, debris, extras — not market sale price
- Review
- After renovations and at each renewal
Direct answer
What is underinsurance? It is a limit that cannot do the job you thought you bought. For a home, that job is usually rebuilding the building and paying the extra costs the wording includes or excludes. For contents, it is replacing what you listed at the basis the PDS describes. If the sum insured is too low, a total loss leaves you funding the gap. If the wording includes an average or co-insurance clause, a partial loss can also be cut back in proportion to how underinsured you were.
A cheaper home premium that was produced by a lower sum insured is not a comparison win. It is a different product. Line the rebuild or replacement figure up first, then compare the premiums you were actually quoted.
This page is general information. It is not a calculator, a quote, or personal advice. Eligibility, definitions and whether an average clause exists sit in the PDS and schedule.
The diagram is illustrative. It does not show a typical dollar gap or a ranked insurer.
Sum insured is a limit, not a vibe
The schedule prints a number. That number is a ceiling, not a compliment. After exclusions, excesses and any contribution clause, the insurer’s payment will not exceed the relevant limit.
People set the number from the wrong inputs:
- Sale price or bank valuation. Those figures include land, location prestige, and a market. Fire does not burn the title. Rebuild is a construction job.
- What you paid years ago. Materials, labour, codes and demolition costs move. A figure that felt ample at purchase can be short after a renovation or a construction boom.
- A quote-form default. Some paths pre-fill a sum from postcode heuristics. Heuristics are not a site inspection.
- A round number that “looks like enough.” Enough is a rebuild estimate plus the extras the wording does not automatically add.
MoneySmart’s home insurance guidance is the consumer-language starting point. The PDS is still the product. The home insurance type page applies the comparison method to buildings and contents. Motor has a cousin problem — agreed versus market value on a write-off — which belongs on the car insurance hub, not on a rebuild calculator. Health products fail on waits and categories rather than sums insured; do not import a rebuild habit into health insurance.
Total loss versus partial loss
Total loss. If the building is destroyed and the sum insured is below the cost to rebuild to the standard the policy describes, you fund the difference — unless the wording is a rare “total replacement” style product with its own conditions. Do not assume “total replacement” from a brochure sentence. Find the clause.
Partial loss. Many people think a mid-sized kitchen claim on a house “worth lots” will simply pay minus excess. If an average or co-insurance clause applies, the insurer may pay only the proportion that the sum insured bears to the full rebuild value. A large underinsurance gap can shrink a medium claim. Whether that clause exists, and how it is calculated, is a PDS question we will not answer for a named current product.
Write both scenarios on the sheet. A product that looks fine on a total-loss story can still be harsh on a partial loss, or the reverse.
What a rebuild estimate needs to include
A serious rebuild figure is a construction budget, not an auction result. The list below is a prompt, not an engineer’s report.
| Cost bucket | Why it is easy to miss | Where to check |
|---|---|---|
| Demolition and debris | The old structure must leave before the new one arrives | PDS extra-cost clauses |
| Professional fees | Architect, engineer, certifier | Included, sub-limited, or extra? |
| Compliance upgrades | Current codes, bushfire or flood overlays, accessibility | Local rules + wording |
| Temporary accommodation | Months, not nights, after a serious event | Sub-limit and definition of “uninhabitable” |
| Outbuildings and structures | Sheds, jetties, pools, retaining walls, solar, fences | Listed or excluded |
| Heritage or unusual finishes | Labour and materials are not volume-builder rates | Specialist estimate |
| Contents and portable items | Separate policy or section; listing thresholds | Contents schedule |
| Landlord extras | Loss of rent is not owner-occupier alternative accommodation | Landlord PDS |
If you cannot complete the table, you are not ready to treat two home premiums as comparable. The quotes checklist puts sum insured as its own row.
We will not invent a rebuild cost per square metre for a capital-city weatherboard. Those figures go stale and vary by site.
Contents underinsurance is quieter
Buildings get the headlines. Contents fail in the wardrobe. People estimate “what I could sell the furniture for” instead of “what it would cost to re-establish a household at today’s retail, after the basis in the PDS”. Indemnity versus new-for-old (or similar language) changes the number. High-value items may need listing. Tools, jewellery, bicycles and collected goods often have sub-limits unless specified.
Renters are not immune. A landlord policy is usually about the building and some landlord risks, not your sofa. Pair contents questions with the type hub when it exists, and still read the PDS.
Portable-valuables extras and phone-plan insurance can duplicate a tiny limit after a large excess. That is overlap, not a rebuild plan. See bundling policies.
How underinsurance interacts with price and exclusions
A low sum insured usually lowers the premium, because the insurer’s maximum payout falls. Comparing that premium to a quote with a higher, more realistic sum and calling the first one “cheaper” is the same accounting error described in how to compare.
Exclusions can create a functional underinsurance even when the dollar limit looks large. A flood definition that does not meet the water that actually enters, or a storm-surge carve-out, is a zero payout on that event. Read exclusions explained alongside this page. A perfect rebuild figure does not help if the event is in “we will not pay”.
What affects premiums lists sum insured as a lever. Treat it as a risk-sizing lever, not as a discount code.
A method for setting and reviewing the number
- Name the object. Building only, contents only, both, landlord, strata — strata buildings are often the owners corporation’s problem, with contents and some fixtures sitting with you. Confirm who insures what.
- Get a rebuild or replacement estimate from a method you can defend: a calculator used as a start, a quantity surveyor or builder for unusual homes, an inventory for contents. Record the date and the assumptions.
- Map extras the PDS does not automatically swallow. Debris, fees, accommodation, landscaping.
- Force every quote onto that figure (or the nearest the form allows). If a path will not let you raise the sum, write “different product”.
- Search the PDS for average, co-insurance, underinsurance, and proportional reduction.
- Revisit after a renovation, a granny flat, solar, a bushfire-standard upgrade, or a jump in local build costs — and at each renewal. A renewal letter that only moves the premium is not a rebuild review.
If you switch insurers, do not cancel the old policy until the new schedule shows the sum you intended. A cover gap on a building is not a theoretical problem. See switching insurers.
Application honesty and the duty of care
Guessing a low sum to win a premium, or omitting a renovation because the form was fiddly, can become a claims argument. The duty to take reasonable care not to make a misrepresentation applies to the answers that set the risk. A claims team that discovers a substantially different building has more to work with than a rounding error.
If a figure was typed to satisfy a slider, fix it before you need the policy.
Strata, landlords and the “someone else insures the building” trap
A lot of Australian households do not insure a free-standing house. Strata buildings are often the owners corporation’s policy. You may still need contents, some fixtures, temporary accommodation that the building policy will not pay, and liability that sits with you. Confirm the split in writing before you treat a low contents premium as proof the building is “covered by the body corp” in the way you imagine.
Landlords have a different job again: building or strata-lot issues, loss of rent, malicious damage, and tenant-related conditions that owner-occupier wordings do not copy. A cheap landlord invoice that used an owner-occupier rebuild guess is two errors stacked.
In both cases the underinsurance test is the same: what limit, for which object, after which definition. The type hubs exist so you do not import house habits into a lot or a rental.
What we will not tell you
- A “safe” percentage buffer that works for every Australian roof.
- Which current insurer pays “total replacement” without conditions.
- A cheapest home-and-contents bundle in any capital city.
- A dollar example that looks like a live quote.
Compare offers is a stub, not a rebuild tool. For complaints that have completed internal dispute resolution, AFCA handles many general-insurance disputes. Keep the estimate, the schedule and the PDS version you bought.
After a near-miss or a small claim
A small payout is a prompt to re-open the sum insured. So is a neighbour’s rebuild story, a council overlay change, or a contractor who will not commit to last year’s rate.
Return to excess vs premium if you also raised the excess to “offset” a higher sum. You may have fixed the limit and broken the first-loss. Both numbers have to be fundable.
The disclaimer and methodology repeat the boundary: we publish a method for sizing the risk, not a market of invented premiums.
Price mechanic
Excess versus premium
A lower premium is often the insurer handing you a larger first-loss. That is rational only if you can fund every stacked excess in cash. Align the excess rows, then compare the premiums you were actually quoted — never a banner number from another year.
- Write the standard, voluntary, age, inexperienced and event excesses for each quote.
- Ask whether more than one can apply on the same claim.
- If you cannot fund the stack, the “saving” is not a saving.
Worked comparison
A like-for-like experiment (no live prices)
Two quotes for the same person, the same object, and the same event. Only one row is allowed to move. We will not invent the invoices — you fill those from quotes you actually received.
Quote A — thicker promise
- Named event is in the “we will pay” chapter
- Excess stack written in full
- Sum insured or benefit period you can defend
- Extras you would actually use
Quote B — thinner invoice
- Same event? If not, stop ranking
- Higher or extra excess you may not fund
- Lower sum, shorter wait, or a missing extra
- Looks cheaper because the promise shrank
If you cannot say which single row changed, you do not have a price comparison. You have two products.
Like-for-like worksheet
Copy this into a notes app. Leave the premium cell empty until every other cell matches across quotes.
| Row | What to write | Quote A | Quote B |
|---|---|---|---|
| Event named | Storm, smash, hospital, vet, rent stop — one sentence | — | — |
| Cover layer | Comprehensive vs TPPD; hospital vs extras; accident vs illness | — | — |
| Listed people / use | Drivers, tenants, occupation, destination | — | — |
| Excess stack | Standard + voluntary + age + event | — | — |
| Limits / valuation | Rebuild, agreed vs market, annual cap, benefit period | — | — |
| Waits & exclusions | Pre-existing, flood, sports, “we will not pay” | — | — |
| Extras ticked | Windscreen, hire car, portable, flood option | — | — |
| Premium you were quoted | Last column — only after the rows above match | — | — |
Like-for-like quote checklist
Tick these before you rank invoices. A missing tick means you are comparing different products.
1.Same event named on both quotes
A cheaper tile that never pays your event is a different product.
2.Same excess stack
Age, inexperienced, event and voluntary excesses can add on the claim day.
3.Same sum insured or benefit period
A lower rebuild figure or a shorter income-protection benefit looks cheaper.
4.Same exclusions and waiting periods
Flood, pre-existing, sports and waiting tables hide in the PDS, not the price.
5.Same listed people and use
Unlisted drivers, business use or a tenanted property change both price and claims.
6.Same extras ticked
Adding hire-car on one quote and not the other breaks the comparison.
Where price hides in the PDS
Search the PDF for “we will not”, “limit”, “excess”, “waiting” and the name of the extra you ticked.
Sub-limits inside a “full” sum insured
Jewellery, bikes, temporary accommodation and similar lines often have their own caps. The headline sum is not the payout for every item.
Optional extras that were never optional on the tile
A quote may include windscreen, portable cover or flood as a default tick. Untick and the price moves — and so does the product.
Waiting periods that buy a cheaper start date
Health, pet and income-protection prices can look lower when the wait is longer. The cheap month is unpaid if the event lands in the wait.
Market value versus agreed or rebuild
A lower valuation basis can lower the premium and the settlement. Line the basis up before you rank the invoices.
Price myths we will not print as facts
Not a method
“The cheapest quote is the cheapest insurance.”
A lower invoice often means a thinner promise, a higher excess stack, or a waiting period that would decline the event you named.
Not a method
“A comparison tile is already like-for-like.”
Tiles freeze a few fields. Excess stacks, extras, flood, and listed people live in the PDS and schedule.
Not a method
“If I did not claim, the renewal cannot rise.”
Book-level costs, rebuild or repair inflation, and a factor on your schedule can move the price without a claim from you.
Not a method
“Bundling always saves money.”
A multi-policy discount can hide a weaker wording. Compare each product as if the discount did not exist.
Questions to take to an issuer
Ask these in writing. A shrug is a reason to keep shopping the document, not the tile.
1.Which event on my one-line brief does this product actually pay?
If the issuer cannot point to a PDS chapter, you are shopping a brand, not cover.
2.Which excesses can apply on the same claim, and can I fund the stack?
The large number on the quote form is rarely the whole first-loss.
3.What is excluded under a different name — flood vs storm, illness vs accident, own vs any occupation?
Definitions, not brochure adjectives, decide the payout.
4.What waiting period starts if I buy this week and the event happens next month?
A cheaper start date can be an unpaid month.
5.If I cancel mid-term or switch, when does the old cover end and the new cover start?
A gap is more expensive than a day of overlap.
6.What would a misrepresentation on this application do to a later claim?
A cheap quote that depends on a guessed answer is not a comparison win.
Related price long-tails
Car
How much does car insurance cost in Australia?
How comprehensive and third-party prices are formed — no invented averages.
Home
How much does home insurance cost in Australia?
Rebuild, flood wording and excess — the rows that move a home premium.
Contents
Contents insurance cost in Australia
Portable limits and apartment contents — not a cheaper building policy.
Health
How much does private health insurance cost?
Hospital versus extras, waiting periods and rebate mechanics in general terms.
Life
Does life insurance cost more with age?
Age, health and benefit design — not a priced table of funds.
Travel
Travel insurance cost for an overseas trip
Destination, sports and medical rules that move a travel premium.
After you finish this page
- 1. Write the event in one sentence.
- 2. Fill the like-for-like worksheet from two real quotes — not from this website.
- 3. Read the PDS chapters you ticked as risks.
- 4. Only then rank the premiums you were given.
Frequently asked questions
What is underinsurance?
Underinsurance means the sum insured (or other limit) is too low to rebuild the building, replace the contents, or meet another limit you would need after the event. On a total loss you fund the gap. On a partial loss, some property wordings also reduce the claim by the underinsurance proportion. The PDS decides whether that clause exists.
Is the sum insured the same as the property’s market value?
Usually not for buildings. Market value includes land. A rebuild is labour, materials, demolition, professional fees and often temporary accommodation. Using a sale-price guess as the sum insured is a common way to create a gap. Use a rebuild estimate, then read how the PDS defines the limit.
Does a cheaper home premium mean I am safely insured?
No. A low premium can be the price of a low sum insured. That is a different, thinner product. Align the rebuild figure across quotes before you rank the numbers you were offered.