Windows
Grey Dirty Drapes, Left 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 (5 POIs)
The Rendon Residence (tier 2), Blue Birdie (tier 1), Cobweb Cottage (tier 1), Crispwell Residence, Lovejoy Apartments.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.