The stonemason’s lodge accomodates experts at cutting stones. With every level, the stability of buildings and wall in the same village increases by 10%.
Please notice that the stonemason’s lodge can only be built in the capital.
The level dependent attributes (such as construction costs, generated culture points and durability) can be found here.
For the full table of construction times click this link for server with 1x speed and this link for server with 3x speed.