Looking at an interesting older renovated house. But below the kitchen, where new underfloor heating has been installed, there is the old basement from the house's origin in the 50s. The pictures show moss and moisture along the walls and exposed rock/stone in one corner. There is an older drain with questionable function. What can/should be done to prevent the moisture from spreading further? The idea is not to use the basement for anything else from the start. Maybe a wine cellar eventually, but no living space that would require special measures. What techniques exist to address this from the inside to avoid drainage/sealing from the outside?
The obvious solution is to install a dehumidifier (or several). This can go quite a long way if you don't plan to furnish the basement. Then, you need to find out where the moisture is coming from; if it seeps in through the walls, it's difficult to manage without external drainage.