Owning your own home

My provider lets you choose how the overpayments work (reduce term or something else) and you can 'get them back' so to speak if you need help.

You can also get offset mortgages that do a similar thing: take the balance of a savings account off the total owed, while leaving it in place, saving you interest payments. But I imagine the account has to be with the lender, possibly a specific product, perhaps not paying much interest... Still.