A national minimum bedroom size could be introduced by the Government under new proposals to tackle rogue landlords and overcrowding.
A discussion paper published by the Department for Communities and Local Government sets out plans to clamp down on criminal landlords who cram tenants into unsafe, overcrowded homes.
Under the measures, local authorities would not be permitted to allow rooms smaller than 6.5 sq.m to be considered as bedrooms in licence applications for houses of multiple occupancy.
The proposals will help councils tackle the problem head-on, and bring an end to landlords who exploit their tenants - charging them extortionate rents to live in cramped conditions.
The paper, announced by Housing minister Brandon Lewis, sets out plans to improve standards of shared homes in England by extending mandatory licensing to smaller and medium sized properties.
Where a landlord fails to obtain a licence they are liable to pay a potentially unlimited fine.
Mr Lewis said: "It is simply unacceptable that people are living in cramped, unsafe accommodation provided by landlords who are more interested in a quick profit than the safety or welfare of their tenants.
"The actions of these rogue landlords are helping fuel illegal working, benefit fraud, and illegal immigration by creating a shadow housing market that carries dangers to people's health as well as communities."
The proposals intend to make it easier for local authorities to raise standards in houses used as shared homes by making the rules apply to more shared homes, including those that are one to two storey.
They also aim to ensure the rules are applied to poorly converted blocks of flats above and below shops, which are often exempt.