Homeowners who find they can't afford a mortgage by themselves are increasingly reconsidering their options and giving thought to renting out their spare rooms, new research suggests.

Nevertheless, with 26 million bedrooms currently standing empty in the UK, the property portal suggests that there is considerable scope for such trends to develop further.

But the National Landlords Association has cautioned against homeowners committing to such practices too hastily.

"The extra income a lodger can provide is great but people should be cautious of relying on it - lodgers are short-term and landlords should be wary of relying this income," commented NLA chairman David Salusbury.

The Inland Revenue currently allows homeowners to earn around £350 a month tax-free through its rent-a-room scheme.