The present invention is a frame brick (10) having a brick body (12) made of composite material and which is in hollow box form and which comprises at least one type of fiber and at least one type of resin, and at least one connection extension (15) which is one-piece with said brick body (12) and which provides connection to another structure element with the same characteristics. As an improvement, at least one cutout (201) is provided at least partially in the direction of the height of the brick body (12) on at least one of two wall surfaces (20) extending mutually on a brick length section (19) of the brick body (12).