Attic Window Quilt Block Pattern

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How to Sew an Attic Window Quilt Block

The Attic Window quilt block is a beautiful and popular design that creates a striking three-dimensional effect, giving the impression of looking out through a window. It uses three fabrics: one for the window frame, one for the sash, and one for the background.

Materials Needed

• Fabric for the window frame (color of your choice)
• Fabric for the window sash (color of your choice)
• Fabric for the background (color of your choice)
• Rotary cutter and cutting mat
• Ruler
• Iron and ironing board
• Sewing machine and thread
• Pins

Cutting Guide

For a 12" finished block:

• Window frame fabric: four 2½" × block-length strips
• Window sash fabric: two 2½" × block-length strips
• Background fabric: one 13" square (finished size + ½" on each side)

Step-by-Step Instructions

1. Arrange the window frame strips around the edges of the background square. Place them right sides together with the background square and pin in place.
2. Sew the strips to the background square with a ¼" seam allowance. Press seam allowances toward the window frame.
3. Cut the center of the background square along the vertical and horizontal axis to create four equal smaller squares. Do not cut through the window frame strips.
4. Fold the sash strips in half lengthwise and press to create a crease down the center.
5. Place the sash strips over the cut edges of the window frame, aligning the crease with the cut edge. Pin in place.
6. Sew the sash strips to the window frame with a ¼" seam allowance. Press seam allowances toward the sash strips.
7. Repeat steps 5–6 for the other two sides of the window frame.
8. Press the entire block carefully, avoiding stretching or distorting the seams.

Your Attic Window quilt block is complete! Repeat these steps to create additional blocks and assemble them into a quilt top.

Covered Corners Method

The covered corners method is a quick and accurate way to add diagonal corner accents to any block without cutting triangles separately.

How to Resize Quilt Blocks

The first step in modifying any quilt block is to decide on your finished block size. You can base this on doubling a pattern, cutting it in half, or working with your available fabric.

Note: When working from a pattern's cutting instructions, remove the seam allowance before scaling. For example, if your pattern calls for 3½″ squares, subtract the seam allowance (½″), double the finished size (3″ → 6″), then add the seam allowance back (½″) — giving you a 6½″ cut piece.

Resizing Square Blocks

Add ½″ to your finished block measurement. For a 4″ finished square, cut a 4½″ square of fabric.

Resizing Rectangular Blocks

Add ½″ to both the length and width. To double a 3″ × 4″ block, cut a 6½″ × 8½″ rectangle.

Resizing Half-Square Triangle Blocks

Add 7/8″ to the desired finished block size. For a 4″ finished HST block, cut 4⅞″ squares.

Resizing Quarter Square Triangle Blocks

Add 1¼″ to the desired finished block size. For a 4″ finished block, cut 5¼″ squares.