Windows
White Dirty Drapes, Right Half Top
A cloth stable block with 5 hit points.
Changes into
When its hit points run out it becomes 
Curtain Rod.
Drops when destroyed
Cloth Fragment× 1-3
Where to find (3 POIs)
Ash & Splash Lodge, Deepwell Shack, Scavengers' Rest.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.