Shelter has issued a report to MPs and councils warning them that 360,000 families in England are being torn apart by overcrowded housing conditions.
Crowded House was published last week and is part of the charity's established One Million Children campaign.
The report warns that thousands more families will suffer unless the Government provides urgent and greater investment in affordable, family-sized homes - defined as social housing with three or more bedrooms.
The report outlines that current house-building is nowhere near enough to tackle the problem.
It estimates that only 4,934 affordable family-sized homes were built last year, compared to the 55,000 yearly total the charity says is needed across England.