Move from ESA to UC question

I am Appointee for my son who is on IR ESA in Support group and gets Severe Disability Premium and Housing Benefit. His landlord is in the process of getting planning permission to rebuild the complex of flats where my son lives which will entail demolishing the current flats so my son will have to go into temporary accommodation for two or three years. This may mean a move to a different borough. If he has to move borough temporarily for this reason will that still generate a move to UC ? If so will Severe Disability premium be lost ?

Thank you Gary for your response.

I had thought that as the temporary accommodation was due to a planning application that it might have made a difference to the rules, but those rules are clearly set in stone without any leeway in unusual circumstances.

As my son's Appointee and carer I shall insist that the temporary accommodation the landlord and local authority finds is within the borough. GP wants it not only within the borough but within the catchment area of the surgery, as do I, so this will clinch it.

Anne