Emergency accommodation , if it is run by the local authority is for those who declare themselves homeless. Examples can be careleavers, victims of domestic violence, those leaving prison, those whose homes are no longer habitable, asylum seekers etc, new tenants i.e young families (young mums leaving home with babies) Those leaving psychiatric care.
In fact anyone who is homeless.
My sister lives near a young person's emergency hostel and it's hell.The police no longer attend, as they were there all the time. (not being alarmist, just saying how it is)
My experience locally is that if it is young people in it, it tends to attract lots of other young people. However, I've professionally worked with people in emergency accommodation, who are very nice and have no difficulties other than they have nowhere to live.
Hope this helps