Remaining balance after the fixed-rate period

Short answer #

Calculate the amortisation schedule to the end of the fixed-rate period. Remaining debt determines refinancing risk; test higher, equal and lower follow-on rates as scenarios.

Important variables #

• Price, rent and holding period
• Rate, principal and remaining balance
• Buying, maintenance and selling cost
• Appreciation and alternative return

Worked example #

If €250,000 remains after ten years, a follow-on rate rising from 3% to 5% initially adds about €417 monthly interest.

Break-even: What changes the result? #

Test the main driver as a cautious, central and optimistic range. Also check whether the ranking reverses at a crossover or remains robust across the range.

Common mistakes #

• Comparing mortgage payment directly with rent
• Omitting transaction cost or remaining debt
• Treating appreciation as guaranteed

Sources & assumptions

• Deutsche Bundesbank — Bank Lending Survey Germany, July 2026 (2026-08-17)
• RATIOXA — Methodology and formulas (2026-08-17)