People who are lucky enough to have a basement in their house often appear to use it for the storage of junk and clutter. I know folks who not only store their own clutter but also their friend’s furniture from when they moved house and couldn’t fit it all in. This is such a waste of valuable real estate! It is really a reasonable option to clear the room and convert it to an extra room.
A basement (providing it is around 2.4 metres high) can be such a marvellous resource for those who need more space and planning permission is not usually needed to convert an existing basement though it is worthwhile checking with the planning department. The problems encountered in converting a basement to a living space are mainly to do with whether the room is dampIf so, there are two issues: firstly there will be the need for a damp proof course and secondly, in order to prevent condensation and consequent fungi and mould there will need to be good ventilation through the room. Ideally the heating would be by electricity as gas would need a flue and create moisture in the air If you want to use the new room as, say a games or play room or a home cinema it probably won’t matter if there is no natural light, though if the basement already has natural light with high level windows it will be OK to use it as a room or rooms for working or sleeping