Deciding matters by majority voting is the standard way local authorities make decisions. It is established in the 1972 Local Government Act, Part VI, section 39(1), and almost certainly repeated in your council's standing orders. I have some sympathy with the view that very important issues leading to fundamental change shouldn't be decided by a small majority (to pluck an example from the air I might mention the EU referendum) but I suggest that requiring unanimity for council decisions, leaving aside the well established principle of majority voting, is not practicable.