London Stair Quilt Block Pattern

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How to Sew a London Stair Quilt Block

The London Stair quilt block is a fun and beginner-friendly design using squares and rectangles in two contrasting colors arranged to create a bold staircase effect. When assembled into a quilt, the stairs create a striking diagonal movement across the whole top!

Materials Needed

• Two contrasting fabrics (Color A and Color B)
• Sewing machine and thread
• Rotary cutter, cutting mat, and ruler

Cutting Guide

• Color A (main fabric): 4 squares — 4½" × 4½"
• Color B (contrast fabric): 2 squares — 4½" × 4½", and 2 rectangles — 2½" × 4½"

Step-by-Step Instructions

1. Place one Color B square right side up. Place one Color A square right side down on top, aligning the edges. Sew a ¼" seam along one edge. Press the seam toward Color A. Repeat with the second Color A and Color B squares.
2. Place one Color B rectangle right side up. Place one of the sewn Color A units right side down on top, aligning the edges. Sew a ¼" seam along one edge. Press the seam toward Color B. Repeat with the second Color B rectangle and second Color A unit.
3. Place one Color A square right side up. Place one of the units from step 2 right side down on top, aligning the edges. Sew a ¼" seam along one edge. Press the seam toward Color A. Repeat with the remaining Color A square and unit.
4. Place the two completed units right sides together, aligning the seams. Sew a ¼" seam along one edge. Press the seam in your preferred direction.

Your London Stair quilt block is complete! When assembling your quilt top, pay attention to the direction of the stairs to ensure they all face the same way for a consistent staircase effect.

Four Patch Technique

The secret to the perfect four patch is pressing seams so they butt together when joined.

Cut two A squares and two B squares. Using chain piecing, join one A square to one B square, right sides together, with a scant ¼" seam allowance. Press toward the dark fabric.

Press all seams toward the dark fabric so they butt up. Place the two A/B units right sides together, butting seams. Pin if needed, join with a scant ¼" seam allowance, then press.

You can apply this technique to all kinds of four patch blocks. As long as a block has a 4×4 grid, the basic principles apply.

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.