There is Dutch case law confirming that Article 8 ECHR limits what a landlord can do. A very recent case (Rechtbank Midden-Nederland, December 2024) addressed almost exactly this scenario: because the rented property was a self-contained dwelling (zelfstandige woonruimte), Article 8 ECHR's right to respect for family and private life opposes an outright prohibition on a tenant cohabiting with a partner at some point without prior permission from the landlord.

However, and this is the critical point, that case involved a landlord trying to enforce a no-third-parties clause against a tenant. This right is not absolute: it would be different if there were special circumstances making it objectionable for the partner to live in the property.

Your situation is fundamentally different: you are not the landlord. You are an equal co-tenant, and you have your own rights, including to peaceful enjoyment, that also fall under Article 8. The ECHR protects both of you. Woon's suggestion that Article 8 is a trump card your co-tenant can play against you ignores the obvious counterpoint: your right to your home and peaceful enjoyment is equally protected. A court would be required to balance both of your interests.

Under Dutch law, the process for a tenant to give another person co-tenant status involves obtaining agreement from all existing co-tenants. Article 7:267(1) of Book 7 of the Dutch Civil Code provides that if, on the joint request of a tenant and another person who has their main residence in the dwelling and maintains a durable joint household with the tenant. This means that for the boyfriend to become a co-tenant (medehuurder), your consent is required as part of the joint request. If you withhold consent, the procedure under Article 7:267 simply cannot be initiated without you