Sheer mass is the only real way to stop bass frequencies from the kick and low tom drums. It will also stop any higher frequencies too providing there aren’t 'leaks' in the construction.
Absorbent foam is effective in taming higher frequencies in reasonable thickness, it must be metres thick to tame bass frequencies (even the best anechoic chambers are only effective down to 50Hz or so). That said, if you only have hard surfaces inside the shed then some foam will be essential to get reasonable sound, without it it'll sound indistinct and will be hard to play as you won't hear the sticking/subtleties properly.
You're looking at a heavy brick shed construction with heavy roof (NOT tin!) and fire door/soundproof door with some foam on the internal walls
Absorbent foam is effective in taming higher frequencies in reasonable thickness, it must be metres thick to tame bass frequencies (even the best anechoic chambers are only effective down to 50Hz or so). That said, if you only have hard surfaces inside the shed then some foam will be essential to get reasonable sound, without it it'll sound indistinct and will be hard to play as you won't hear the sticking/subtleties properly.
You're looking at a heavy brick shed construction with heavy roof (NOT tin!) and fire door/soundproof door with some foam on the internal walls
