The trend is twice as common among those aged 18-30, though more than half a million 31-44 year olds have rushed in to living together.
The survey also reveals how the high cost of housing is trapping couples whose relationship has broken down.
The YouGov survey shows 3.6 million people have been forced to continue living with a partner because they can’t afford to live separately.
Shelter's Chief Executive, Campbell Robb said:
‘This research shows the extraordinary impact that the cost of housing is having on people’s lives and relationships.
It’s shocking that so many people say they are rushing their relationships because they literally can’t afford to live without their other half. Just as concerning is the news that so many couples who have split up are unable to make the final break due to the cost of moving out and starting again.
We have to start asking ourselves whether it’s acceptable that people’s lives are being dictated by the cost of housing in this way.
