In order to simplify cleanliness, window sills should be sloped toward the room and down at an angle of ______ degrees:

When considering the design of window sills for optimal cleanliness, a slope towards the room at an angle of 30 degrees is ideal. This specified angle helps facilitate effective drainage of water and debris away from the window, minimizing the accumulation of dirt and moisture.

A 30-degree slope allows for a gentle yet effective angle where debris won't easily settle, and any water that may condense or spill will flow away rather than pool, which could lead to mold growth or other cleanliness issues. This angle also helps in ease of maintenance, as it directs cleaning efforts towards the interior of the room rather than creating hard-to-reach areas that could foster unsanitary conditions.

This design consideration is essential in both residential and commercial settings, where maintaining a clean and hygienic environment is a priority for overall health standards, and a proper window sill slope aids in achieving that goal.