How to Measure for a Roof Lantern: Step-by-Step Guide

Tom Warren
May 11
1 min read

Measuring Up: Ensure Your Roof Lantern Fits Perfectly

Ordering a roof lantern is exciting – but accurate measurements are key. Whether you're replacing an existing unit or cutting a new opening, here’s how to measure for a perfect fit.

Step 1: Internal vs External

Are your measurements based on internal ceiling space or external kerb dimensions? Stratus Lanterns are sized to external kerb dimensions.

Step 2: Measure the Kerb Opening

Measure the external edge-to-edge dimensions of your upstand or kerb. Note the width and length in millimetres or centimetres.

Step 3: Allow for Overhang

Most lanterns overhang the kerb by a small margin to ensure weatherproofing. Check with us if unsure – we’re happy to guide you.

Step 4: Choose the Style

From 2-way rectangular designs to square pyramid lanterns, your measurement may suit multiple styles. Our team can help you select the most suitable shape.