Turn a few drops of water into a hands-on engineering challenge!

In this complete 45-minute STEM lesson, children aged 7–11 explore how water behaves on different materials, then design, build, test and improve a miniature rainproof roof. Inspired by the water-repellent surface of a lotus leaf, pupils discover how observations from nature can spark design ideas.

Using everyday classroom materials, children compare paper towel, waxed paper and aluminum foil, record their observations and choose a roof material using evidence. They test their shelter, change one feature and investigate whether their improvement helps keep the tissue inside dry.

What’s included:

• 15-slide presentation in editable PowerPoint and PDF formats.
• 12 A4 printable pages, supplied as PDF and editable PowerPoint.
• 8-page teacher guide in editable Word and PDF formats, with learning objectives, success criteria, exact timings, teaching scripts, preparation checklist and suggested answers.
• Support, Core and Challenge worksheets for differentiated learning.
• Two accessible SEN/SEND worksheets with large material illustrations, tracing, matching, coloring and choices between two answers.
• Picture vocabulary cards, sentence starters and team role cards.
• Roof planning sheets, test records, an evidence-check extension and four exit tickets per page.

Skills developed: observation, prediction, fair testing, material comparison, evidence-based reasoning, collaboration and iterative design.

You will need: water, droppers, trays, clear plastic cups, paper towel, waxed paper, aluminum foil, tape, tissue, pencils and a timer. Teacher preparation is required to cut material samples and organize trays.

All teaching and pupil text is in English. The resource uses a consistent nature-inspired design with realistic illustrations. Text and layout elements are editable in the supplied source files; illustrations are separate image objects.

Suitable for primary science, STEM enrichment, homeschool learning and an introduction to biomimicry. No internet connection is needed during the lesson.