The £100,000 Mistake: Why So Many High-Value Homes Are Underinsured

When many people think about home insurance, they assume the most important figure is the market value of their property.

After all, if your home is worth £1 million, surely that’s the amount you need to insure it for?  Not necessarily.

In fact, one of the most common mistakes we see among owners of higher-value homes is underinsurance, where the amount insured isn’t enough to fully rebuild the property or replace its contents following a major loss.

The consequences can be significant.  In some cases, homeowners discover they’re underinsured by tens of thousands of pounds.  In others, the shortfall can exceed £100,000.

The problem is that many people don’t realise there’s an issue until they need to make a claim.

  

Underinsurance is More Common Than You Think

The word “underinsurance” sounds straightforward, but it affects properties in a variety of ways.

A homeowner may have arranged their policy several years ago and never reviewed it since.  They may have completed renovations, added an extension, upgraded the kitchen or invested in high-value contents without updating their insurer.

Some may have simply guessed the rebuilding cost when completing a proposal form.

Others assume that the property’s market value and rebuilding cost are the same thing.  They rarely are.

For high-value homes in particular, the gap between the two figures can be substantial.

  

Rebuild Cost vs Market Value: Understanding the Difference

One of the biggest causes of underinsurance is confusion between market value and rebuild cost.

Market value is what someone would pay to buy your property.

Rebuild cost is what it would cost to reconstruct the home if it were completely destroyed by an event such as a fire.

That includes:

• Demolition and site clearance
• Architects’ fees
• Surveyors’ fees
• Planning costs
• Labour and materials
• Specialist craftsmanship
• Compliance with current building regulations

For many high-value properties, particularly listed buildings, period homes or architect-designed residences, the rebuilding cost can be dramatically different from the sale price.

In some areas, land values account for a significant proportion of market value.  In other cases, specialist materials and construction methods can make rebuilding considerably more expensive than homeowners expect.

This is why insurers and brokers focus on rebuild cost rather than property value when assessing appropriate cover.

 

The Hidden Impact of Home Improvements

Over the last few years, many homeowners have invested heavily in their properties.

Extensions, garden rooms, home offices, cinema rooms, bespoke kitchens and smart technology installations have become increasingly common.

While these improvements may increase enjoyment of the property, they can also increase rebuilding costs.

The challenge is that insurance policies aren’t always updated at the same time as the improvements.

Imagine spending £120,000 on an extension.  If your insurer is never informed, your sum insured may no longer accurately reflect the true rebuilding cost of the property.

Similarly, luxury features such as:

• Handmade kitchens
• Stone flooring
• Specialist glazing
• Smart home systems
• Air source heat pumps
• Swimming pools
• Wine cellars

can significantly alter the cost of restoring a property after a major loss.

What was adequate cover five years ago may no longer be adequate today.

 

Rising Construction Costs Have Changed the Picture

Even homeowners who haven’t made any changes to their property may still face an underinsurance problem.

Construction costs have increased substantially in recent years due to inflation, labour shortages, supply chain pressures and rising material costs.

As a result, rebuilding a home today may cost considerably more than it would have done when the policy was first arranged.

Many insurers apply automatic inflation adjustments at renewal, but these may not always keep pace with the reality of specialist or high-value property rebuild costs.

For owners of larger homes, period properties and bespoke residences, regular reviews are particularly important.

 

What Happens if You’re Underinsured?

Many homeowners assume that if they’re underinsured, the insurer will simply pay up to the policy limit.

Unfortunately, the situation can be more complicated.

Many policies contain what’s known as the “average clause”.  In simple terms, if a property is insured for less than its correct value, the insurer may reduce a claim proportionately.

For example:

If a property should be insured for £1,000,000 but is only insured for £800,000, it is effectively underinsured by 20%.

If a claim for £200,000 arises, the insurer may only pay 80% of the loss, resulting in a settlement of £160,000.

The homeowner would need to fund the remaining £40,000 themselves.

This often comes as an unpleasant surprise because many clients assume partial claims will be paid in full.

The reality is that underinsurance can affect claims of all sizes, not just total losses.

  

High-Value Contents Are Frequently Overlooked

Property isn’t the only area where underinsurance occurs.  Contents values are often underestimated too.

Over time, possessions accumulate.  Jewellery collections grow.  Watches increase in value.  Artwork is acquired.  Technology is upgraded.

Many people could not accurately estimate the replacement cost of everything inside their home.

Particularly common areas of underinsurance include:

• Jewellery
• Luxury watches
• Fine art
• Antiques
• Designer handbags
• Collectibles
• Home entertainment systems
• Wine collections

In some cases, individual items may exceed limits that require separate specification on a policy.

If those items haven’t been declared correctly, cover may be restricted.

 

Why High-Net-Worth Insurance Is Different

One reason underinsurance can be more prevalent among affluent homeowners is that standard insurance solutions aren’t always designed with complex risks in mind.

Higher-value properties often involve unique features that require more detailed consideration.

Specialist high-net-worth insurance typically places greater emphasis on:

• Accurate valuations
• Tailored sums insured
• Art and collections cover
• Worldwide personal possessions
• Specialist claims handling
• Regular reviews

The objective isn’t simply to arrange insurance.

It’s to ensure the protection keeps pace with changes in both the property and the lifestyle of the owner.

  

Five Questions Every Homeowner Should Ask

If you’re unsure whether your cover remains adequate, ask yourself the following:

1) When was my insurance last reviewed?
If it’s been more than a couple of years, it’s worth revisiting.

2) Have I renovated, extended or improved the property?
Any significant changes could affect rebuild costs.

3) Have I acquired valuable possessions?
Jewellery, watches, artwork and collectibles should be reviewed regularly.

4) Do I know the rebuilding cost of my home?
Many homeowners don’t, yet it’s one of the most important figures on the policy.

5) Could I provide an accurate inventory of my valuables if I needed to make a claim?
If not, you may be underestimating the true value of your contents and possessions.

  

The Real Cost of Getting It Wrong

Most homeowners never expect to suffer a major loss.

Yet fires, escape of water incidents, storms and other unforeseen events happen every day.

Insurance is easy to ignore when everything is working as it should.  However, when a serious claim occurs, that’s when the quality and accuracy of your cover truly matters.

The difference between being correctly insured and underinsured can amount to tens of thousands of pounds, sometimes considerably more.

For many homeowners, avoiding a potential £100,000 mistake starts with something surprisingly simple: making sure their insurance reflects the true value of what they’re protecting.

 

Frequently Asked Questions

How do I find out the rebuild cost of my home?
A professional rebuild valuation is often the most reliable method, particularly for larger, listed or non-standard properties.  Some insurers and brokers can also provide guidance based on specialist valuation tools.

Does my property’s market value matter for insurance?
Not usually.  Insurers are primarily concerned with the rebuilding cost rather than the amount your property could be sold for.

Should I update my insurer after home improvements?
Yes.  Any significant renovations, extensions or high-value additions should be disclosed to ensure your cover remains accurate.

Can underinsurance affect small claims?
Potentially, yes.  If an average clause applies, insurers may reduce settlements proportionately, even where the claim is not a total loss.

How often should I review my home insurance?
As a general rule, annually and whenever there are significant changes to your property, contents or lifestyle.

 

Protect What Matters Most

For owners of high-value homes, insurance should be more than a yearly renewal exercise.   It should be a regular review of whether your property, possessions and lifestyle are protected to the standard you expect.

At COHIBL, we help private clients understand the risks that may not be immediately obvious, including underinsurance, valuation issues and gaps in cover that could prove costly in the event of a claim.

A professional review today could help prevent an expensive surprise tomorrow.