As well as giving homeowners some extra cash, the lodging trend may also reflect the increased number of prospective first-time buyers lodging while they save for deposits in these uncertain times.
What can you earn?
A room at a premium address in a central area can rent for £800 a month, says Spareroom.co.uk, while the average UK rent is £393 a month - or about £4,700 a year.
What about tax?
Live-in landlords can legitimately avoid tax on much of their extra income, receiving £4,250 of rent a year tax-free - regardless of their other income. To qualify for the allowance, the let accommodation must be furnished and can be a single room or a whole floor, but the property must be your only or main home.
Landlords don’t need to do anything to get the tax break if the rent is below £4,250 and they don’t normally file a tax return. Those earning higher rents are expected to tell their tax office, and claim the allowance through their returns. The allowance is reduced to £2,125 each for people who jointly own properties and applies in full to tenants who are allowed to sub-let.