Because no one knows your home or situation better than you do, it needs to be up to you to provide your sum insured. Each home is unique, made from a variety of different materials, to different qualities and sizes, and it is important that the sum insured reflects this.
If you get an online quote for your Home Insurance on aainsurance.co.nz, you'll notice we've included questions from the Cordell Sum Sure Calculator. This is to give you an indication of how much your sum insured could be. However, it's up to you to check this figure, to make sure it's right for you and your circumstances.