Hello everyone,
thanks for the first feedback.
I only mentioned my girlfriend because a new kitchen, furniture, and so on will be installed, and she will cover the costs.
The house is not renovated; rather, new water pipes were installed 1-2 years ago, new bathrooms, solar system, and floors. It is simply in a "normal" condition: plastic windows, oil heating, insulated roof—just everything without any fancy extras.
A notice of termination for personal use should not be a problem because the tenants have only been there for 2 years, I officially live in the house, and I actually do need it for personal use.
If the building societies want a land charge, it should be no problem to put it on my paid-off property and on the new house, right?
Regards