What most property owners get wrong about their cover, and what it costs them at claim time.

Not by statute, but close to it in practice. Your buy to let lender will almost always make buildings cover a condition of the loan, and a leasehold block's lease normally obliges the freeholder to insure. The trap runs the other way too: most residential home policies exclude a property the moment it is let, so a landlord relying on one is often uninsured without realising it.

It covers your legal liability if someone is injured, or their property damaged, because of your building. A tenant hurt by a loose stair rail, a visitor hit by a falling roof tile, a contractor injured in a communal area. It matters because a buildings claim is capped by the rebuild cost and an injury claim is not. Limits commonly run between £2m and £10m, and the low end is often not enough for a block with communal areas.

Rebuild value rather than market value, plus location, construction, use, occupancy and claims history.

• Construction. Non standard construction, flat roofs above a certain percentage, timber frame and listed buildings all move the price.
• Tenant type. Residential, student and specialist lets are rated differently.
• Occupancy. Unoccupied property is the single biggest step change in most policies.
• Claims. Escape of water is the most common and most expensive property claim in the UK, and a run of them will show.

We will not quote a price on a web page. Anyone who does is guessing, and you would be entitled to hold them to it.

This is where most property owners get caught. Nearly every policy has an unoccupancy clause, typically 30 or 45 consecutive days, after which cover drops back to fire, lightning, explosion and aircraft only. No escape of water, no theft, no malicious damage, at exactly the point the property is empty and most exposed. Refurbishment usually counts as unoccupied too. Tell your broker before the void starts, because very few insurers will extend the period retrospectively.

Some do, many do not, and this is a common gap. Letting room by room to unrelated occupants is a materially different risk from a single family let, and many mainstream landlord policies either exclude it or void cover if a property is converted mid term without telling the insurer. If you run HMOs you want an insurer with real HMO appetite, rating on lettable rooms, and malicious damage by tenants included rather than stripped out.

Yes, and usually in your favour. A freehold block normally needs a combined policy covering the building, communal areas, property owners' liability, loss of rent, and often directors and officers cover where the freehold sits in a management or right to manage company, with the sum insured set by a proper reinstatement valuation rather than a figure carried forward for years. Past a handful of properties, a portfolio policy puts everything on one schedule, one renewal date and one premium, and usually prices better because the insurer is rating a spread of risk.

Build costs have risen sharply and most sums insured have not kept pace, because they roll forward at a small index each renewal instead of being reassessed. It bites through the condition of average. Insure a building for £400,000 when the true rebuild cost is £600,000 and the insurer can reduce a claim by the same proportion, so a £60,000 escape of water claim pays £40,000. That applies to partial claims, not just total losses. Rebuild cost is not market value and it is not what you paid.