Multi-property landlords face a multiplier effect – especially in winter
When you own several properties, the risk of underinsurance doesn’t rise gradually.
It multiplies.
Storm damage, escape of water, unoccupied periods between lets, older roofs, ageing plumbing, student turnover, HMOs, mixed property types – all these risks increase the chances that one or more of your properties will suffer a winter incident.
And if your sums insured are inaccurate, every affected property can expose you to financial losses at the very moment you need the cover most.
In 2026, many landlords are still relying on outdated rebuild figures set years ago. Some are based on market value rather than true rebuilding cost. Others haven’t been revisited after extensions, refurbishments or tenant-driven alterations. Inflation in building materials and labour has also pushed rebuild costs significantly higher in recent years.
When you multiply these factors across a portfolio, the potential exposure becomes serious.
Underinsurance doesn’t just reduce “big claims” – it reduces every claim
Most property policies contain an “average” clause.
If your property is underinsured, the insurer may reduce any claim payout by the same percentage of underinsurance – regardless of whether the claim was major or minor.
For example:
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Correct rebuild cost: £1,200,000 (across several properties)
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Actual sum insured: £900,000
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Underinsurance: 25%
If you suffer a £20,000 escape-of-water claim on one property, the insurer may legally reduce the payout by that same 25%:
£20,000 × (900,000 ÷ 1,200,000) = £15,000 paid
You cover the missing £5,000
Now imagine multiple winter claims across different units.
The financial impact is no longer inconvenient.
It’s strategic.
Five reasons portfolio landlords are at greatest risk in winter
1. Higher likelihood of a winter incident across multiple units
With more properties, the probability of at least one winter claim rises sharply – storm damage, frozen pipes, roof failure, drainage issues or escape of water.
2. Inconsistent rebuild values between properties
Many portfolios have a mix of:
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Older terraced houses
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Flats with leasehold complications
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New-builds
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HMOs
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Holiday lets
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Properties with previous extensions or non-standard construction
These require individual rebuild considerations, but sums insured are often copied or indexed without a fresh check.
3. Renovations not reflected in the policy
Refurbishments that improve kitchens, bathrooms or structure increase rebuild cost.
But unless these are flagged and the policy updated, underinsurance is almost inevitable.
4. Multiple properties = multiple tenants = multiple unoccupancy periods
Void periods over winter can restrict cover if heating, inspections or security conditions are not met.
5. Portfolio growth outpaces policy updates
It’s common for landlords to add units over time while leaving older rebuild values untouched.
This is exactly why portfolio landlords suffer disproportionate underinsurance at claim time.
How to confirm accurate rebuild values across your portfolio
It is your responsibility as the policyholder to set correct rebuild values.
Neither NetRent nor Clear Insurance Management can calculate rebuild costs for you – but we can guide you toward reliable methods:
Option 1: Use the ABI/BCIS online calculator
For many standard-construction homes, you can use the calculator at abi.bcis.co.uk to get an estimated rebuild cost.
This is a quick way to ensure you’re not working from an outdated or inaccurate figure.
Option 2: Commission a professional Rebuild Cost Assessment
For larger, older, extended or mixed-construction portfolios, a professional assessment is strongly recommended.
NetRent provides access to a Rebuild Cost Assessment service, offering detailed reports and recommended rebuild costs.
You can find the service on our website at:
netrentinsuranceservices.co.uk/rebuild-cost-assessment/
Many landlords choose to commission assessments for selected “key” properties first – such as their highest-value or most complex units – then update the rest.
Why winter is the ideal moment for a portfolio-wide insurance review
A winter review isn’t just about sums insured.
It’s about your strategic resilience as a landlord.
Our portfolio reviews typically consider:
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When each property last had its rebuild cost checked
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Whether the sum insured aligns with that rebuild value
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Any recent refurbishments or extensions
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Changes in tenant profile or occupancy
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Unoccupancy conditions across the portfolio
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Exposure of any units to storm, flood or escape-of-water risk
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Whether loss of rent cover mirrors your actual rental income
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Where HMOs or multi-unit buildings require more specific wording
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Whether optional covers (Accidental Damage, Malicious Damage by Tenants, Home Emergency, Legal Expenses) are appropriately structured
The goal is simple:
Whatever this winter brings, your portfolio should be financially protected, not financially exposed.
How NetRent and Clear support portfolio landlords
As one of the largest introducers of landlord insurance in the UK, NetRent works with thousands of landlords, including many multi-property owners.
Through our insurance partner, Clear Insurance Management Ltd, portfolio landlords benefit from:
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A dedicated NetRent team specialising in property and landlord insurance
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The ability to place cover with a wide range of insurers, tailoring policies to portfolio complexity
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In-house claims support, helping guide you through any winter incidents
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Expertise in HMOs, holiday lets, blocks, portfolio consolidation and directors/LLP structures
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Guidance on how to obtain accurate rebuild values and align those with the right insurance structure
You handle the rebuild values.
We help you turn accurate information into robust, responsive cover.
What to do now
If you already insure your portfolio through NetRent
Request a 2026 winter portfolio review.
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Tell us how many properties you have and your renewal dates
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We’ll assess your current structure and highlight potential underinsurance risks
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We’ll guide you through next steps, including using the ABI/BCIS calculator or our Rebuild Cost Assessment service
If you’re new to NetRent
Request a portfolio landlord insurance quotation and rebuild-value guidance.
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Share basic information about your properties
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Our NetRent team at Clear will review your existing cover and compare it against the wider market
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We’ll show you how to structure your portfolio more effectively for 2026
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, and accurate rebuild values are essential to structuring that cover.
Contact us
Telephone: 01352 721300
Email: insurance@netrent.co.uk