We have our building insurance and contents insurance from the same people. We have 4 years NC and just got our new premiums for next year. It's gone up £14 a month. Had a closer look and realised they are calculating this based on a rebuild cost of 800k which seems absurd for a 1930 semi. I tried a few other sites and they calculated a rebuild cost of just under 500k. Very tempted to change. Do I need to check with my mortgage company ?