Hiya. I’ve been a Housing Benefits assessment officer for 10 years now and the housing element of UC is very similar.
You don’t automatically get an increased housing allowance just because of a DLA award however, if your child’s disability means they can’t share a room, you can apply for the ‘additional room rate’.
This can increase your housing element.
If you’re in social housing it can only be increased if you currently have the under occupancy charge)
If you are in private rented it can only be increased if you are receiving below the maximum LHA rate which for my area is 4 bedrooms. For example if you are currently deemed as needing a 3 bedroom house based on your household composition you will only receive the 3 bed LHA rate.
If you are then deemed to need an extra room as your child’s disability means they are unable to share, it will increase your LHA rate to 4 bed. All authority’s have their own separate LHA rates but the difference in my area is about £30 per week so definitely worth it.
You would need to put a request in for it and provide an explanation and evidence as to why your child is unable to share a bedroom.
I hope that helps and isn’t too confusing 😊