With a family offset mortgage, parents can use their savings to reduce the amount of interest their child pays on their mortgage. The savings are typically locked in for a specific period, with the option for withdrawals, until the child has paid off a significant portion of their mortgage (around 25-30%). This is a beneficial choice for parents who want to help their child save money on purchasing a home without giving away funds permanently. Additionally, this option avoids the risks often linked with other family mortgage products.