When someone is sent to prison for any length of time then . . .
(a) if they own their house (and other possessions) outright then there's no reason why they can't simply be left where they are. They'll probably then be uninsured although the prisoner could appoint someone to seek some basic form of insurance on the property, with the money either coming from the prisoner's savings or perhaps directly from the person seeking the insurance. (For example, the prisoner's son or daughter if the house is to be part of their inheritance). However it's probably more likely that the prisoner would appoint someone to sell everything on his behalf ;
(b) If the house is mortgaged or rented then (unless, say, their partner was able to continue paying the mortgage or rent on their own) the property is going to eventually end up back in the hands of the landlord or of the mortgage lender. (A landlord can't immediately repossess a rented house without notice though. There was one case where a court awarded a prisoner £15,000 damages because the landlord had failed to respect the fact that, even though the guy had been sentenced to life imprisonment, the tenancy agreement was still in place). Such procedures can take time, so that the prisoner could appoint someone to deal with the sale of his other possessions.
However it may be the case that a landlord or mortgage lender eventually ends up with a house still full of the prisoner's possessions. If so, they must abide by the provisions of the Torts (Interference with Goods) Act 1977
https://www.legislation.gov.uk/ukpga/1977/32
and give the prisoner due notice to arrange for the removal of the goods. If he fails to do so they can then sell those possessions but they must take due care to get the best price for them and then pay the money to the prisoner.
With regard to bank accounts, etc, a prisoner can appoint someone to take charge of them. (I've been asked to look after the financial affairs of people in prison on several occasions, with access to their bank accounts).
All of the above can be a bit theoretical though. Some landlords are quick to dispose of the possessions of people in prison (with those prisoners not knowing enough about civil law to be able to safeguard their possessions). I've known someone who was only sent to prison for a few months but, apart from a small box full of his most personal stuff (which was looked after by his local probation services) he lost everything in his house and never got any compensation for it.