About Treehouse Simulator

Design a treehouse, play tower, deck, shed or cabin from real UK timber sizes, and get the framing, the fixings, a cut list, a shopping list and a printable plan.

What it does

• Start from one of over thirty designs, or answer four questions in Help me choose for designs that suit your children and garden.
• Change sizes, shapes, roofs, railings, ladders and slides, and the whole frame rebuilds: posts, beams, joists, studs, rafters and every screw and bolt.
• “Things to check” flags anything too small for its job, too high for young children, or too close to a tree, against common rules of thumb.
• The cut list gives every piece’s length and angles; the shopping list packs them into the lengths timber merchants sell, with typical prices.
• Share a design with a link, or print the plan to take to the timber yard.

How it works

Everything happens in your web browser, on your own computer, tablet or phone. There’s no account to make and nothing to install. Your designs are kept in your browser, so they’re private to you — but that also means clearing your browser’s data deletes them. To keep a copy safe, or move a design to another computer, use Save to download it as a file.

Prices are typical UK prices, including VAT, checked in September 2026: materials only, with no delivery, tools or labour. Your merchant’s prices will differ, and you can change any price in the shopping list.

What it isn’t

Treehouse Simulator is a planning aid, not an engineer or an architect. Its sizes, spans and fixings follow published rules of thumb, not calculations for your timber, your tree or your ground. Read Building safely before you build, and have anything load-bearing checked by someone qualified.

Who made it

Treehouse Simulator was made in the UK by a parent planning a treehouse for their own children, and grew from there.