What is a split mortgage?

A split mortgage is where your loan is divided into two parts (sub-loans), often with different rates (for example, part fixed and part variable). Your total repayment is the sum of both parts.

Why do people choose a split mortgage?

A split loan can balance repayment certainty (fixed part) with flexibility (variable part). The best fit depends on your buffer, risk tolerance, and product constraints.

How can I model a split mortgage with a calculator?

Model each part as a separate scenario (loan amount, rate, term) and combine the repayments. Treat results as estimates and confirm how your lender structures split products.

Do overpayment rules differ on fixed vs variable parts?

They can. Fixed parts may have stricter overpayment limits or fees, while variable parts can be more flexible. Always check product terms.

Split mortgage in Ireland (part fixed, part variable)

A split mortgage can be a practical way to balance certainty and flexibility, but it also means you are effectively managing two sub-loans. This guide shows how to think about it and how to model it as estimates.

Mortgage calculator (estimate)Fixed vs variable Overpayments guide

1) Think of a split as two sub-loans

Each part has its own rate, repayment schedule, and potentially its own constraints. Your household budget feels the combined repayment, so always add both parts when you plan affordability.

2) Model downside risk on the variable part

If one part is variable, use a rate-rise scenario to understand how sensitive the combined repayment is to higher rates. This can help you decide how large the variable portion should be.

3) Confirm flexibility rules per part

Overpayment and switching rules can differ between the fixed and variable portions. Before relying on a plan, confirm what is permitted for each part and whether fees apply.

Loading Tools