How Much Home Insurance Cover Do You Need?

Getting home insurance right comes down to two numbers: what it would cost to rebuild your home, and what it would cost to replace everything inside it. Guess either one and you risk being underinsured — where the insurer scales down a payout to match what you actually declared — or paying for cover you will never use. Here is how to work both out for a UK home in 2026.

Buildings cover: rebuild cost, not market value

The most common mistake is insuring your home for what you paid for it, or what it would sell for. Buildings insurance is based on the rebuild cost — what it would cost to demolish and reconstruct the property from scratch, including labour, materials, debris removal, and architects' fees.

Rebuild cost is almost always lower than market value, because it excludes the land your home sits on — and in much of the UK the land is the expensive part. A flat that would sell for £600,000 might cost £250,000 to rebuild.

To find your figure:

Check your mortgage valuation or lease — many state a reinstatement or rebuild figure directly.
Use the free rebuild-cost calculator from the Building Cost Information Service (BCIS), run by RICS, which most insurers accept.
For period, listed, or non-standard homes (thatch, timber frame), get a surveyor's assessment — standard calculators underestimate these.

Review the figure every year. Building costs have risen sharply since 2021, so an old sum insured can quietly leave you short.

How to value household contents for insurance

Contents insurance covers everything you would take with you if you moved: furniture, electronics, clothes, kitchenware, carpets, and curtains. Most people badly underestimate the total.

The reliable way to value contents is to go room by room and add up the replacement cost — what each item would cost to buy new today, not what you originally paid:

Walk through each room, including the loft, garage, and shed.
List the big items first (sofa, bed, TV, appliances), then work down to the smaller things that add up fast — clothing, books, toys, kitchen contents.
Total each room, then add the rooms together.

Two things catch people out. First, single-item limits: most policies cap any one item (often £1,500–£2,000) unless you list it separately, so name jewellery, bikes, laptops, and musical instruments individually. Second, cover away from home — phones, watches, and holiday luggage usually need "personal possessions" cover added on.

As a rough sense-check, a typical three-bedroom UK home holds £40,000–£60,000 of contents, but your own count always matters more than any average.

Contents insurance coverage recommendations

Buildings sum insured = rebuild cost, reviewed yearly
Contents sum insured = new-for-old replacement value, counted room by room
High-value items listed individually so they clear the single-item limit
Accidental damage and away-from-home cover added only if you actually need them

How the Aviva ChatGPT app helps

Once you know your numbers, the Aviva ChatGPT app gives you a home insurance quote without leaving ChatGPT. When you're ready to buy, you complete your purchase on aviva.com.

Install it from the ChatGPT App tab (or visit chatgpt.com/apps), search "Aviva", and ask in plain English — for example: "What would buildings and contents cover cost for a 3-bed semi in Nottingham that would cost £220,000 to rebuild?"