Because it is a loan and the funds are used to pay off the Association loan (which also has interest) on the Clubhouse. The interest is amortized monthly over the 10-year period much like a mortgage. The sooner the Special Assessment is paid on a Lot, the less interest will be paid by the Member. For example: If a member decides to wait the full 10 years, they will pay $900 in interest and $1500 in principle totaling $2400. If a Member was to pay off the full Special Assessment sometime during the 10 years they will pay only the interest up to the payment date which will make the total paid less than the $2400.