Estate agents should be forced to list the floor space of properties they put up for sale or rent, academics have said as new research revealed more than half of houses in England are failing to meet modern standards on size.
The majority of homes, 55%, do not have a big enough floor area, while more than one in five, or 21%, is short of space when taking into account the number of occupants, the Cambridge University research found.
Flats and small terraced houses were the most commonly undersized, while households with children were most likely to be overcrowded, the research, published in the journal Building Research & Information, found.
The poorest were hit the hardest by a lack of space, with 75% of households losing some of their housing benefit under the so-called "bedroom tax" deemed to be under-sized.
Only 19% of households losing the benefit could be considered to have more space than they need, authors Malcolm Morgan and Dr Heather Cruickshank, of Cambridge University's Centre for Sustainable Development said.
They based their findings on standards set by the Greater London Authority in 2011 for internal space in new homes in the capital, which are comparable to standards set by other organisations across the UK.
Newly built homes in England are the smallest in a league table of floor space of 15 European countries with an average floor space of 76 square metres, compared to 137 in Denmark.
When judged against all homes, England still lagged behind with an average of 85 square metres, beating only Portugal, Greece and Finland.
The report findings, based on a study of more than 16,000 homes - recommends that the internal area of homes should be "clearly stated" by estate agents when renting or buying a home and that all local authorities should set minimum space standards.
They also say that floor area per person should be considered rather than the number of bedrooms when assessing whether a benefit claimant has a larger home than they require.
Mr Morgan, a PhD candidate, and lead author of the report, said at its worst, overcrowding was linked to poor health including asthma and depression and at a less serious level, caused tensions through lack of privacy.
He said buyers and potential renters should be able to search online using floor space as a criterion.
"In most European countries information on floor space is given and everyone will know how big their house is and how much space they need for their family and their activities whereas here we tend to talk about bedrooms," he said.
"If floor area was stated it would create an awareness of whether or not you were moving to a bigger house or a smaller house."