When I applied for my FLR couple of years ago(was on fiancé visa before that), I only submitted proof of address under my name like bank statement, council tax(joint name), electricity/gas bill statement, water bill statement, GP letters,TV license....
But when I applied for my ILR a month ago, the officer from the checking service asked us to include our recent mortgage statement (a strong evidence of the accommodation she said)... So maybe submit your mortgage statement as well just an 'icing on a cake' thing.