D&D 5E (2014) Interior wall construction

[dave2008]

Make sure the door is insulated and has a rubber insulation around the frame. Not worth spending the extra money for a room if everyone can hear everything through the door.

And if you want to get really serious you need to use acoustic sealant at all penetrations through the wall membrane (think outlet boxes, light switches, etc.)!

 

[dave2008]

Also, don't forget about the ceiling and floor too!

 

[Koloth]

For OP's question, look at Post and Beam construction for framing.

Not sure when plaster and lathe came in but pretty sure that is what the 2nd poster is thinking of.

A lot of Fantasy RPG buildings probably just had the outer sheathing and left the interior framing exposed. If you assume a wizard has a research library, bookcases could serve as the inner walls for tiny adventurers to hide behind. If a high enough level wizard, maybe some wall of stone/iron for inner wall sheathing. "Looks like a normal peasant home but for some reason, our ballista bolts are not penetrating."