About

Treehouse plans with the safety details worked out

The Treehouse Planner is a free 3D designer for tree forts and playhouses that stand on their own posts. You draw the treehouse you want; it checks the parts that keep children safe and the frame that holds it up, prices the materials and draws the plan.

Operator: Westernmost LLC
Address: 30 N Gould St Ste R, Sheridan, WY 82801, USA
Email: hello@thetreehouseplanner.com

Who we are

The Treehouse Planner is an independent project operated by Westernmost LLC, 30 N Gould St Ste R, Sheridan, WY 82801, USA. We build planners for backyard projects: one engine per kind of build, written from the published rules, so that every design gets the same checks. If you find a mistake in a rule or a number, tell us: a fix to the engine fixes every design at once.

How the designer works

1
You pick the treehouse
An open fort, a fort with half-walls or a playhouse. Set the size, the deck height, the roof and the way up, and add a slide or a swing set.
2
You set where you build, and who plays
Your snow, frost line and wind, from your building department, and the children's ages. In Canada, your NBC 2020 loads.
3
It checks every part
The guard and its gaps, the posts and footings, the frame, the roof and the clear space around the swing and the slide.
4
It prices and draws it
A materials list priced line by line, and a builder's plan drawn from your own numbers.

Each design gets one of three answers. Ready: every check passes and the builder's plan is for sale. Needs a look: the design can be built, but one part sits outside what the guides cover, so the designer tells you what to check and offers a fix. Can't be built as drawn: something has to change first, and the designer shows you what.

Where the sources say nothing, we chose a value and call it our default, so you can always see which numbers are ours.

Where the rules come from

CPSCU.S. Consumer Product Safety CommissionThe Outdoor Home Playground Safety Handbook (324) and the Public Playground Safety Handbook (325): guard height for children, the gaps where a head can get stuck, the use zone, swing clearance and the slide exit.
DCA6American Wood Council, DCA 6The Prescriptive Residential Wood Deck Construction Guide: posts, beams, joists, footings and how they connect.
IRCInternational Residential CodeGuards and openings (R312), design loads (R301) and the rafter tables for the roof (R802).
NBCNational Building Code of Canada 2020Snow and wind loads, guard heights and lumber values for builds in Canada.
NDSAmerican Wood Council, National Design SpecificationThe wood design rules the knee braces, their bolts and the posts are checked with.
SimpsonSimpson Strong-Tie load tablesThe uplift and sideways ratings of the cast-in post bases.

What we don't do

We don't approve your build. Local approval is not checked. Your building department decides whether you need a permit, how far from the property line the treehouse must stand and which rules apply where you live. Ask them before you dig.

The planner is a planning aid, not an engineer's review or an inspection. What it calculates, and what stays with you, is on the before anyone climbs page. It does not cover:

Attaching anything to a living tree.
Slides other than a bought plastic slide for a 4 ft or 5 ft deck.
Electrical.
Wind over 140 mph, or over 0.65 kPa in Canada.
Earthquake design.
Sites with fill, slopes or weak soil.

How the site is paid for

The designer and the free plans cost nothing and need no account. What pays for them is the builder's plan: a PDF drawn for the treehouse you design, with the posts and footings, the framing, the guard, the way up, the roof, the cut list and the shopping list, for $29 once. If our plan has an error, we fix it or refund you. The site carries no advertising.

Contact

Email hello@thetreehouseplanner.com or use the contact page. Send the design link with your question, so we see the same numbers you do.

Design the treehouse you want

Open the designer