Could a winter claim reveal your rental property is underinsured?

Winter is when underinsurance bites

You don’t usually discover your rental property is underinsured when you buy the policy.
You discover it on the worst winter’s night of the year – when a burst pipe, storm damage or a serious fire forces you to claim.

Across the UK, independent surveys over recent years have repeatedly shown that a large share of buildings are underinsured. At the same time, escape of water has become one of the most common and expensive types of landlord claim, often running into tens of thousands of pounds.

If your sum insured is wrong, winter is when that mistake becomes painfully real.

For single‑property landlords – especially those who became landlords “by accident” – this risk is often hidden. It’s easy to assume:

• “The market value looks about right, I’ll insure for that.”

• “The figure my old insurer suggested a few years ago is still fine.”

• “Index‑linking will sort it, won’t it?”

Unfortunately, that’s exactly how underinsurance creeps in.

What underinsurance actually means in a claim

Underinsurance isn’t just about being a bit short on your sum insured.

If your rebuild cost should be £300,000 but you’re insured for £200,000 (two‑thirds of what you need), then in many cases your insurer is entitled to treat you as underinsured and only pay two‑thirds of any claim, even if the loss is much smaller than the total sum insured.

For example:

• Correct rebuild cost: £300,000

• Sum insured on policy: £200,000

• Serious escape‑of‑water claim: £45,000 to put right

If the insurer applies an “average” clause because of underinsurance, they may only pay:

£45,000 × (200,000 ÷ 300,000) = £30,000

You, as the landlord, could be left to find the remaining £15,000 – on top of your excess – at exactly the same time as you’re losing rent and dealing with disruption.

When you combine:

• Rising construction and materials costs, and

• Higher average claim sizes for escape of water and storm damage

…the cost of guessing your rebuild value is higher than ever.

Why single‑property landlords are especially exposed

Larger portfolio landlords often have regular conversations about sums insured and risk. Many single‑property landlords don’t.

Common patterns we see when landlords come to us through NetRent Insurance Services include:

• Using market value instead of rebuild cost
  Market value is influenced by location and demand. Rebuild cost is about labour, materials and professional fees. They are rarely the same number.

• Relying on outdated figures
  A rebuild estimate from three, five or ten years ago is unlikely to reflect today’s prices. Recent inflation in building materials and labour has had a major impact on true rebuild costs.

• Assuming “standard” is good enough
  Features like extensions, loft conversions, non‑standard materials, or local ground conditions can change the true cost of a rebuild.

• Not updating after improvements
  New kitchens, bathrooms, extensions or external works all add to the rebuild cost – but sums insured are often left unchanged.

Winter: a stress‑test for your policy

Winter increases the chance that you’ll have to find out how good your policy really is:

• Storm damage to roofs, chimneys and outbuildings

• Escape of water from frozen or burst pipes

• Flooding in certain areas

• Unoccupancy between lets, when heating and inspections are often overlooked

For many landlords, the buildings policy hasn’t had a proper review for years. It’s common for owners to admit they haven’t checked their sums insured recently, or that they aren’t completely sure how their policy would respond to a serious winter claim.

That’s why winter is the perfect moment to ask a simple question:

“If I had a serious winter claim next week, am I sure my policy would respond as I expect – and in full?”

A 7‑question self‑check for single‑property landlords

Use these questions as a quick sense‑check. If you answer “no” or “not sure” to any of them, it’s a strong sign you should get a professional review.

1. Do I know my current sum insured is based on a rebuild cost, not the market value?

2. Has that rebuild figure been properly reviewed in the last 12–18 months?

3. Have I updated the policy since any major work (extensions, conversions, new kitchen/bathrooms, structural changes)?

4. Do I understand the unoccupancy conditions – what happens to cover if the property is empty between tenants in winter?

5. Do I know how escape of water is covered, and any specific requirements around heating and inspections?

6. Am I confident that tenant types and property use on the policy match reality? (for example, not described as a “single family let” when it’s effectively an HMO‑style arrangement)

7. Do I know who I would actually speak to and what would happen if I had to make a claim tomorrow?

If any of those questions raise doubts, you’re not alone – and that’s exactly what we’re here to help with.

How to obtain an accurate rebuild cost

Neither NetRent nor Clear Insurance Management can calculate a rebuild cost for you. The responsibility for setting an appropriate sum insured always rests with you as the policyholder.

However, there are practical ways to get a more accurate figure:

• Use an independent calculator
  For many standard‑type homes, you can use the online calculator provided by the Association of British Insurers and the Building Cost Information Service at abi.bcis.co.uk to help estimate a suitable rebuild cost.

• Commission a professional assessment
  For greater certainty – and especially for larger, older, extended or non‑standard properties – a professional assessment is strongly recommended.
  NetRent offers access to a Rebuild Cost Assessment service, which provides an expert report setting out a recommended rebuild cost. You can find details on the Rebuild Cost Assessment page of our website at netrentinsuranceservices.co.uk/rebuild-cost-assessment/.

Once you have an accurate rebuild cost, you can then set your buildings sum insured accordingly and keep it under regular review.

How NetRent and Clear help you get this right

NetRent Insurance Services is one of the largest introducers of landlord insurance in the UK, working with thousands of landlords and letting agents.

Our insurance partner, Clear Insurance Management Ltd, is an independent Chartered insurance broker with extensive expertise in the property sector and a dedicated team for NetRent landlords.

That means when you ask us to review your cover, you get:

• A dedicated NetRent team at Clear who specialise in landlord and property owners’ insurance.

• Access to a wide range of insurers, not just a single company’s products.

• Support not only in arranging cover, but also from Clear’s in‑house claims team when something goes wrong.

A typical winter review for a single‑property landlord will look at:

• How and when you last obtained your rebuild cost, and whether it may now need updating

• Whether your current sum insured properly reflects the rebuild cost you’ve obtained

• Any changes in construction, improvements or extensions that might not yet be reflected

• Tenant profile and occupancy (including any HMO‑style arrangements)

• Unoccupancy conditions and how they interact with winter voids

• Options to include or refine cover such as:

  • Accidental and malicious damage by tenants

  • Loss of rent and alternative accommodation

  • Property owners’ liability limits

  • Home Emergency cover, where appropriate

We can’t set the rebuild cost for you – but we can guide you on how to obtain it, help you interpret the implications for your insurance, and make sure your policy is structured around the correct figure.

What to do now

If you’re already insured through NetRent

If you already arrange your landlord insurance through NetRent:

Ask us for a 2026 winter cover review, including guidance on checking your rebuild cost.

• Tell us your renewal date and property details

• Our NetRent team at Clear will review your current cover and highlight any potential issues

• We’ll talk you through options such as using the ABI/BCIS calculator or commissioning a Rebuild Cost Assessment if needed

If you’re new to NetRent

If you’re currently insured elsewhere or not sure your policy is still right:

Request an expert landlord insurance quotation, plus guidance on confirming an accurate rebuild cost.

• We’ll gather some basic information about your property and current cover

• The NetRent team at Clear will compare your existing arrangements with what’s available across the market

• You’ll receive a tailored recommendation, and information about tools such as the ABI/BCIS calculator and our Rebuild Cost Assessment service

Regulatory note

NetRent Insurance Services is a trading name of NetRent Ltd. NetRent Ltd is an Appointed Representative of Clear Insurance Management Ltd, which is authorised and regulated by the Financial Conduct Authority.

This article is for general information only and doesn’t constitute personal advice. The right cover for you will depend on your specific circumstances, which is why a proper review – and an accurate rebuild cost – are so important.

Contact us

Telephone: 01352 721300
Email: insurance@netrent.co.uk