Underinsurance or co-insurance is a part of the fine print in your commercial property insurance policy which obliges you to try and insure your building for the full replacement value. If you insure for less, the insurer may be able to reduce how much they pay you in the event of a claim. This can catch people out as they may think they are insured enough to replace their roof, but find the insurer only pays a portion of the actual cost if there is a claim. An experienced commercial property insurance broker can help guide you on this with some general cost estimates and direct you to a formal valuer if required.