How can I terminate a rental agreement with a co-tenant?

Questioner

As of February 1, I live together in an apartment with a friend, hereafter roommate. We have a rental agreement for an indefinite period with a minimum of 12 months. However, it now turns out that roommate actually wants to live with his girlfriend. She is here 80% of the time. As a result, I have to share my apartment with an extra person, while I did not ask for it or sign for it. For me, this is a huge violation of my privacy, my personal space and my living pleasure. After having had several conversations with my roommate and making this known, he did not want to change his behavior. In the meantime, I have become overstressed by this situation, while I am starting a new job as of March 1. In order to protect myself, my mental and physical health and my job, I have decided that I can no longer live in the apartment. I packed my things and left. Because I would like to come to a solution to solve this, I have drawn up an agreement. In this agreement, I have written down a number of agreements that I would like to make with him. He does not want to agree to this, which is fine, but he does not come up with other proposals for other solutions. He and I have a tenancy agreement with the landlord. It states that he and I are tenants 'as applicable both separately and jointly'. Does this mean that I can terminate my tenancy agreement? Or do I need his permission to do this? And can I enter into an agreement with him in which we make arrangements that is legally valid? He says that is not possible, because we have to involve the landlord. But I think the landlord just wants to see money and they don't care how it comes about, as long as it comes about. Hopefully you can help me with this situation!

Lawyer

You are a co-tenant and that means that you can terminate the lease at any time with a one-month notice period. Outstanding deposit and purchased movable property will have to be divided.