1. Your financials
2. Partner financials
3. House
4. Mortgage rates (NHG, April 2026 defaults)
5. Sub-rent (kamerverhuur) — tax-free up to € 6.633 / yr
The kamerverhuurvrijstelling (KVV) lets you collect up to € 6.633 / year from renting a room in your owner-occupied home completely tax-free — no income tax, the rented portion stays in Box 1. Cliff edge: earn even €1 over → the entire amount becomes taxable at 37,56 % Box 1 (not just the excess), and the rented share may shift to Box 3.
6. Extra repayment
7. Starterslening — optional municipality starter loan
An SVn-administered second mortgage some municipalities offer to first-time buyers — bridges the gap between your LTI cap and the home price. Wageningen does not participate; pick a nearby gemeente. Payment-free for years 1–3 (rente is paid by the SVn fund, not capitalised), then amortises over the remaining 27 years at 4.40 % (15-year fixed). The numbers below assume you take the loan you specify on top of your primary mortgage.
Source: SVn leningzoeker API + per-product-page parse, svn.nl product page · Rate: svn.nl/rentetarieven (4.40 %, 15y fixed; 4.00 % toetsrente). Year-15 rate reset NOT modelled.
Scenario comparison — 8 setups side by side
How is "viability" computed?
Per-scenario amortisation breakdown
How to read the chart: bars and cost lines use the LEFT axis (€ per year you spend);
the emerald line uses the RIGHT axis (€ of loan still owed — a much bigger range).
Each year you pay a fixed monthly amount to the bank. That amount splits into:
loan repayment (cyan, shrinks your debt) +
interest (magenta, the bank's profit). The full bar = total cash sent to the bank that year.
The Dutch tax office refunds part of the interest (the HRA — hypotheekrenteaftrek); the dashed
yellow line shows what you actually pay after that refund.
If you rent out a room, the dotted violet line subtracts that rent income too.
Year by year the yellow line creeps closer to the bar top — less interest paid = less HRA refund.
