A combination mortgage bundles several interest models and maturities within the same financing. In practice, a portion of the amount is often taken out as a fixed-rate mortgage with a clear interest-rate lock-in, while the other portion is held as a money-market–oriented SARON mortgage. This creates a mix of predictability and flexibility. The fixed portion stabilizes the monthly payment, while the SARON portion stays closer to the market price of money and can benefit if rates remain stable or fall. Those who want additional flexibility can temporarily use a small variable tranche, for example to bridge between two decisions.

A variable mortgage is a financing product without a fixed interest commitment and without a predetermined end date. The interest rate is adjusted by the bank at regular intervals, usually with a contractually agreed notice or adjustment period. It is based on the bank’s refinancing costs plus an individual margin, but does not automatically follow a published reference rate like SARON. As a result, the variable mortgage behaves like an “open” loan: it can be terminated at any time as long as the notice and timing provisions are observed.