DIY homeowners and cowboy builders trying to shoehorn as much living space as they can in to a home may have problems with their home insurance.
Around 3 million homeowners are trapped in a property they cannot leave because they cannot raise a mortgage to trade up for a larger home.
Now thousands of homeowners are staying put and trying to maximise their space with DIY and extensions.
A study by home insurance firm LV= reckons 190,000 children have seen their sleeping space partitioned, while families are busy converting lofts, garages and understairs cupboards in to living space.
Although many of these projects do not need planning permission, they may still contravene building regulations that govern rules like overcrowding and fire safety.
One in eight (13 per cent) families who modified their homes have not checked whether home modifications comply with building regulations, while just one in 50 (2 per cent) say they are sure they do not.
The council must check structural changes to make sure they match the regulations. This could include knocking down internal walls and changes of use.
Homeowners also need to ensure they tell their insurer about any noteworthy changes in their home. Or they may find their home insurance is void in the event of a claim.
Besides growing families putting a strain on living space, more workers have a home office that encroaches on living space. Numbers of home workers have soared by a fifth (20 per cent) since 2008, says LV=.
John O’Roarke, of LV= home insurance, said: “Families are feeling the squeeze as they are being forced to live in smaller homes than are suitable for their needs. High property prices have forced many families to remain in a house that they have outgrown and many are resorting to desperate measures to create extra space.
“Research found hundreds of thousands of families are now living with makeshift modifications, which could be illegal and unsafe.
“Building regulations ensure that home modifications are safe, and we urge all those considering modifying their home to ensure any changes they make meet regulation standards.”