宀 Radical 40 — roof; a building, a dwelling

Where the shape comes from

A house seen from the front: the dot is the ridge pole, the wide hook the roof and the two walls falling away on either side. It never stands alone — it sits on top of characters that name what happens indoors: 家, 字, 安, 客.

characters filed under 宀

• 室shì (fourth tone, falling)a room, a chamber; an office or department within an institution9
• 家jiā (first tone, high and level)home; family, household; a specialist (as a suffix, e.g. 画家 painter); measure word for shops and businesses10