An Attic Window calculator is available for different sizes, number and methods of blocks for your own project.
Fabric InstructionsBackground: Cut 1 square 2½ inches.
Light Fabric: Cut 2 squares 2½ inches. Cut 2 half square triangles from 2½ inch strip.
Medium Fabric: Cut 2 half square triangles from 2½ inch strip.
Dark Fabric: Cut 2 squares 2½ inches. Cut 4 half square triangles from 2½ inch strip.
Half Square Triangle InstructionsCutting: Using a side right triangle ruler or template, cut half square triangles. Move ruler/template upside down for next cut when necessary.
Sewing: Sew ¼ inch seam on long side of triangle pair. Press seam to one side.
Layout Attic Window block as shown. Chain piece together using ¼ inch seam, sewing first rows, then columns. Press seams to one side.