Prepayment
Ensure that you have some form of prepayment clause in your mortgage that will allow you to pay down your mortgage with a lump sum or an extra payment and without any penalties.
Portability
This means you can transfer the terms and conditions of your mortgage to your next home. This may allow you to keep an existing low interest rate if you sell one house and buy another.
Assumability
Assumability allows you to assume (take over) the existing mortgage on a property. An existing mortgage may have a lower interest rate than the current market offers so it could make sense to assume this mortgage. In turn, an assumable mortgage may be a selling feature for you when you decide to put your house on the market.
Expandability
This lets you expand the principal on a first mortgage or increase your mortgage at the lenders agreed-upon rate of interest. This can be a cost-effective way to finance a home renovation or free up some of the equity in your property.