I have just bought a cottage that has pine paneling on the interior walls (floor to ceiling). My first thought was to tear this down and put up drywall. But then I started to wonder if I could put the drywall directly on the paneling??? Sure, it adds a bit of thickness but I'm going to replace windows etc. etc. anyway so there won't be any extra work with trim.
Reflections...
On one hand, it's usually not particularly difficult to tear down paneling (unless it's glued with something excessively strong)...
On the other hand, with the window replacement, it wouldn't be much extra work to add onto it either, and then you have the advantage of having something behind the drywall that you can nail/screw into well enough for, e.g., pictures and small shelves (but hardly sufficient for wall-mounted TVs and the like).
On the third hand, I don’t know if I would feel entirely comfortable attaching drywall solely to the paneling. Paneling is often quite a flimsy material and even more flimsy in how it's fastened, some older panel clips, for instance, are really, really poor. So I would still want to try to screw the drywall into the underlying studs as much as possible, and that might be a bit hard to find with the paneling still in place, perhaps?
On one hand, it's usually not particularly difficult to tear down paneling (unless it's glued with something excessively strong)...
On the other hand, with the window replacement, it wouldn't be much extra work to add onto it either, and then you have the advantage of having something behind the drywall that you can nail/screw into well enough for, e.g., pictures and small shelves (but hardly sufficient for wall-mounted TVs and the like).
On the third hand, I don’t know if I would feel entirely comfortable attaching drywall solely to the paneling. Paneling is often quite a flimsy material and even more flimsy in how it's fastened, some older panel clips, for instance, are really, really poor. So I would still want to try to screw the drywall into the underlying studs as much as possible, and that might be a bit hard to find with the paneling still in place, perhaps?
If the panel is well installed, like nailed, it's probably easier to just put on a sheet than to tear down and possibly install new double gypsum. I used 6 mm renovation gypsum on my pine paneling and am satisfied with the result.
For God's sake, save the panel. Then you have material behind the drywall that is sufficient to screw into. You won't have to plug everything up! Just make sure to screw into the studs behind where you have the opportunity.
Ok I'll keep the panel 
But I have to make sure that no gypsum joint comes between two panel boards? It goes in about ½ cm there or something..
How do I know exactly where the studs are without tearing down a lot?
But I have to make sure that no gypsum joint comes between two panel boards? It goes in about ½ cm there or something..How do I know exactly where the studs are without tearing down a lot?
You can usually see the nail rows in the panel if they are not overfilled and painted.