You do realise that most new build social housing is extremely small and as many as possible are squeezed into as small a space as possible?
My last social housing house was a '3-bed' according to the HA. The largest bedroom in the house was 10x11ft, and two DC were sharing it.
The next smallest bedroom was 9x10ft, and me, my Ex-P and DS3 were sharing it.
My DD was in a bedroom that was 5x9ft, but due to the alcove for the stairs, you could only fit a toddler bed in there. She was in there until she was 13yo and 5ft2. In a toddler bed she couldn't stretch out to sleep in.
It's not all roses in social housing - the flat before that house was in an area like Baghdad, in fact the local nickname WAS little Baghdad.
I'm now IN a larger, 4 bed social housing house, but again, the bedrooms are tiny, and the garden is so small that if all 4 of my DC stand on the grass, in the four corners, they can all hold hands, and DS3 is only 16mo, so doesn't have long arms!!
AND I am paying £100 a month top up on my rent out of my benefits for the privilege of my DD being able to sleep lying flat in her bed, out of my benefits. And when I go and get a job in 18 months time, I will have to find most of the money to pay my £720 rent, if not all of it.
My tenancy isn't 'for life' either, it will be reassessed every 2 years. Not that I'll ever be able to afford private rented here, even a 3-bed would be more than I could earn in a month!!
I didn't choose to be a lone parent, but these things do happen.