Legal advice on tenancy law and ventilation

Questioner

We rent a private home. This home has 1 bedroom, which had no windows or anything, so no ventilation and no daylight. When we brought this up with the landlord, he came up with the proposal to have a window installed, but because we had not asked for it ourselves, we had to pay half of it. We ended up paying €600 to the landlord for the window. But I still don't feel comfortable.. Isn't it mandatory to have daylight and ventilation in a bedroom? We don't have to pay for that, do we? After all, it is also the property of the landlord to whom we helped pay for a window. If we paid wrongly, can we claim this amount back? Thank you in advance!

Lawyer

art. 7: 206 section 1 BW, states that the landlord has a repair obligation and must repair this immediately. By this co-payment, the landlord is enriched by this placement of the window. You can reclaim this amount or claim compensation for this enrichment. If desired, you may contact me directly.