An architectural house style featuring steeply-angled sides (roofline) that usually begin at or near the foundation line, and meet at the top in the shape of the letter A. An A-frame ceiling can be open to the top rafters.

A-Frame house with an Interlock Metal Roofing System

Aged Copper Shake

Merriam-Webster Online Dictionary
A-frame (noun)
a support structure shaped like the letter A
a building typically having triangular front and rear walls and a roof reaching to or nearly to the ground