Landlords of shared houses would be required to improve their energy efficiency under new laws proposed by a former Labour minister.
Alan Whitehead said rules which will prevent homes with an F or G-rating for energy efficiency being let only apply if the whole property is rented by a single tenant.
Under his proposals, the measure would be extended to houses in multiple occupancy (HMOs), enabling tenants to request improvement measures and preventing landlords from renting out draughty, cold properties.
The 2011 Energy Act will, from 2016, give some private renters the right to request that their landlord introduce reasonable energy efficiency improvements to their homes.
The Act also requires landlords to make sure their rented properties meet a minimum energy efficiency standard of grade E by 2018.
But these measures did not include all HMOs, as many are rented out by the room rather than under a single agreement.
"That is rather a lot of tenants left out of these improvements," Mr Whitehead told MPs.
"I don't think that's right, not just because tenants in HMOs are more likely than most to be in fuel poverty yet will be paying more in bills than anyone else on this basis after 2018, or that much needed improvements in our housing stock will completely miss an important and known energy inefficient housing sector, but because those new rights should be there for all tenants, regardless of the exact nature of their tenancies."