It is possible to have a same sex marriage ceremony or form a civil partnership in a religious building, as long as the building has been approved for this purpose.
Legal preliminaries referred to as giving notice will need to be completed, in the normal manner, prior to any ceremony.
More information about legal preliminaries to marriage
If opting for a civil partnership the registrars will attend to complete the registration which can be preceded or followed by a religious ceremony or blessing.
Religious Buildings that are approved for this in Hull -
Hull Unitarian Church
St Ninians and St Andrews United Reform Church