According to the realestate.com.au report on Adelaide firm Goodhouse's new eight-star Pocket House, the cost of building a quality home in Australia has become so stretched that developers are now designing smaller, more efficient dwellings just to keep construction affordable. That same cost pressure sitting behind the Pocket House's design brief is quietly undermining a much larger group of Australians: homeowners and landlords whose building insurance sum-insured figures have not kept pace with years of rising construction costs.
The Pocket House Signal: Construction Costs Have Reset Higher
The Goodhouse Pocket House is explicitly a response to the reality that Australia builds the second-largest homes in the world, and that size now carries a price tag many buyers cannot absorb. A smaller, eight-star-rated home at a lower price point only makes commercial sense if the cost of materials, labour and compliance per square metre has risen enough to make size itself the main lever left for affordability. That is a structural statement about where rebuilding costs sit today, not a one-off pricing quirk in a single project.
This matters well beyond new-build buyers. Insurance sum-insured figures are meant to reflect the full cost of demolishing a damaged home and rebuilding it to an equivalent standard, including labour, materials, permits, and often temporary accommodation during the rebuild. When the underlying cost of construction shifts the way the Pocket House story implies, a sum-insured figure calculated even a few years ago can fall meaningfully short of what a full rebuild would actually cost today, regardless of whether the policyholder has consciously changed anything about their cover.
For homeowners and landlords, the practical takeaway is not to assume last year's renewal figure is still accurate. A policy that auto-escalates by a fixed percentage each year may not be tracking actual trade and materials costs in a given region, particularly where local labour shortages or supply constraints have pushed rebuild costs up faster than general inflation. Reviewing the sum-insured figure against a current, independent rebuild estimate is a straightforward way to close that gap before a claim exposes it.
Why Underinsurance Becomes Invisible Until a Claim Is Lodged
Underinsurance rarely announces itself. Premiums are paid, renewal notices arrive, and the policy appears to function normally for years — right up until a total loss event forces an insurer to assess the real cost of rebuilding. At that point, many policies include an averaging or co-insurance clause, meaning that if the sum-insured is found to be materially below the true rebuild cost, the insurer may only pay out a proportion of any claim, not the full amount up to the policy limit. A homeowner who believed they were fully covered can be left funding a significant shortfall out of pocket at the worst possible moment.
The quiet risk in building insurance is not fraud or a denied claim — it is a sum-insured figure that was accurate once and was never revisited as rebuild costs moved higher around it.
This dynamic is particularly relevant for landlords, who may be less hands-on with a property's insurance renewal than an owner-occupier living in the home day to day. A landlord insurance policy bundled through a property manager or set up years ago at purchase can sit unreviewed for extended periods, even as the property itself ages, is renovated, or sees local construction costs shift. Strata properties carry a parallel version of this risk at the building level, where a body corporate's insured value for the whole complex needs periodic reassessment, not a static figure set at the original strata plan registration.
Investors managing multiple properties face a compounding version of the same problem. Each property may have a different build era, finish level and location-specific rebuild cost, meaning a single assumption about sum-insured adequacy applied across a portfolio is unlikely to be accurate for every asset. Those running a structured portfolio-level view of property performance should treat insurance adequacy as part of that same annual review, not a separate administrative task handled only at renewal time.
How Sum-Insured Should Actually Be Calculated
A properly calculated sum-insured figure is not simply the purchase price of the property, nor its current market value — land value is excluded entirely, since land does not need to be rebuilt after a fire or storm. Instead, the figure should reflect the full cost to demolish the existing structure and rebuild it to a comparable standard, including professional fees, council permits, and often a buffer for temporary accommodation costs while the rebuild is underway. Most major insurers provide an online calculator or questionnaire to help estimate this figure, factoring in floor area, construction type, number of storeys, and finish quality.
Renovations are one of the most common triggers for an outdated sum-insured figure. An extension, a kitchen upgrade, or the addition of a second storey all increase the cost of rebuilding, yet many homeowners update their contents cover after a renovation while forgetting that the building sum-insured also needs to rise in step. Similarly, older homes with period features, high ceilings, or heritage overlays can be more expensive to rebuild to an equivalent standard than a volume-built modern home of the same floor area, a detail that a simple square-metre rate calculator may understate.
This is closely linked to the broader purchase decision itself. For buyers weighing up different property types, understanding how strata title differs from Torrens title matters for insurance responsibility: a Torrens title owner insures the whole building themselves, while a strata owner relies on the body corporate's building policy and only needs contents and, in some cases, a top-up policy for fixtures they have personally upgraded.
Practical Steps to Avoid an Underinsurance Shortfall
The most direct action available to any homeowner or landlord is to run a fresh rebuild cost estimate at each renewal, rather than accepting an automatically indexed figure without question. Most insurers' online calculators take only a few minutes and ask for floor area, construction materials, number of bathrooms, and any special features. Comparing this fresh estimate against the existing sum-insured figure on the policy schedule will quickly reveal whether a gap has opened up.
Landlords should treat this review as part of standard annual property management, alongside rent reviews and lease renewals, rather than a one-off task completed only when a policy was first taken out. A quick conversation with the property manager or insurer about whether the sum-insured still reflects current rebuild costs — especially after any renovation, extension, or significant local construction cost movement — can prevent a far more painful conversation after a claim is lodged. Those weighing up whether to buy a new-build, an older renovated home, or a strata apartment should also factor insurance adequacy into the comparison, since the ongoing cost and complexity of keeping cover accurate varies materially between these property types.
For those still working through the fundamentals of how property ownership structures affect ongoing obligations like insurance, engaging a professional early can help. A buyer's agent can flag construction type, age, and rebuild complexity issues during the purchase process itself, giving a new owner a realistic starting point for their first sum-insured calculation rather than guessing at renewal time. For a comprehensive overview, see our Property Insurance Guide.
This article was produced with AI assistance and reviewed for accuracy. Content is for informational purposes only and does not constitute financial or property investment advice.
