Sam Dunn: 'The house we're buying has a flying freehold – what's this?'

Question: We're buying an old house (built around 1900) and our solicitor has just unearthed something called a "flying freehold" in the property documents regarding one of the bedrooms. The law firm says it's nothing to worry about and that we should simply take out insurance to protect us if anything goes wrong, but I've never heard of this problem before. Should we be concerned? GD, Cumbria

Answer: You've stumbled upon one of the more bizarre sideshows of property law, but don't treat it as entertainment – it could scupper your house purchase.

As a concept, it's simple: a flying freehold is a tiny part of a freehold property that either reaches into, or is built on or over, a neighbouring house.

You often find it with semi-detached houses, where an upstairs room lies directly above a shared outdoor passageway. "In a case like this you will not be the owner of the 'land'; you'll simply be the owner of the piece of property that is over the land," a spokesman for the online conveyancer Myhomemove.co.uk says.

Flying freehold issues are also often found inside adjacent households: for example, a first-floor bedroom that partly lies over a downstairs room in your neighbour's property.

It can provoke all sorts of sticky legal issues regarding the cost of repairs to storm damage, say, or major DIY renovation, if your neighbours refuse access or protest at your plans.

"Flying freeholds are a grey area as far as the law is concerned and many lenders will probably not lend you money to buy a property of this type," says a TheMoveChannel.com property website spokesperson.

It often doesn't have to be an issue at all, as long as you maintain friendly relations with your new neighbours in case of any future problems. And much can depend on whether your lender is happy about such a freehold: if they are, then all well and good, but if not, then they'll probably ask for a very common type of cover known as 'flying freehold indemnity insurance'.

This is often easily provided by large insurers and shouldn't cost more than a couple of hundred pounds; it'll protect you from having to shell out if any neighbourly difficulties escalate into an expensive dispute.

However – and this is where it can get tricky – some solicitors or lenders aren't satisfied with indemnities, especially where the flying freehold looks like a major issue. You may run into demands for documents such as a 'deed of access' specifically allowing access in case of emergency, that must be agreed by all sides. Neighbours happy with a flying freehold for many years who now face being asked to sign new, complex legal documents can end up resenting the new owners – ie, you.

Check your lender's position, and hope an indemnity insurance policy is acceptable; if not, you may face a long legal haul before moving in.