STEM kits that don't fill your house

The subscription model has an unspoken cost. Every month, by design, something new arrives. After a year you have twelve finished projects, twelve sets of packaging and a cupboard that has quietly become a graveyard of half-played-with science.

The one-year picture, by brand

• KiwiCo - around twelve assembled cardboard, wood and foam models. The highest accumulation here, and the least durable.
• CrunchLabs - twelve durable mechanical toys. Better, because they actually get played with, but they are still twelve objects.
• Little Passports - twelve kits, heavy on booklets, maps and stickers. Bulky in a different way.
• MEL Science - the reagents are consumed, so accumulation is moderate, but equipment and packaging build up.
• ibrick - one kit, one tray. Nothing further ships; the new content arrives through the app.

If you are staying with a monthly box

Two things genuinely help. Photograph finished builds before dismantling them - most children are far more attached to the record than the object. And set the expectation at the start that builds come apart after a fortnight, rather than negotiating it each time.