Why the mortgage payment is not the true housing cost

Short answer #

A mortgage payment contains interest and principal. Interest is finance cost while principal builds equity. True housing cost also includes maintenance, insurance, charges and opportunity cost; wealth also depends on property value.

Important variables #

• Interest share of payment
• Principal share and balance
• Maintenance and owner-only cost
• Tied-up equity and appreciation

Worked example #

Of a €1,800 payment, €1,100 may be interest and €700 principal. Comparing the full payment with rent incorrectly treats €700 of equity building as lost cost.

Break-even: What changes the result? #

As the balance falls, the interest share declines. High maintenance or low appreciation can still weaken ownership.

Common mistakes #

• Counting principal as cost
• Omitting maintenance
• Comparing gross rather than net wealth

Sources & assumptions

• European Central Bank — Bank interest rate statistics (2026-08-17)
• RATIOXA — Methodology and formulas (2026-08-17)