Checks that explain themselves — and say what they cannot know
OpenCatio3D runs a versioned set of rules over your design and reports findings by severity. Each finding names the rule, the parts it affects, why it matters, how to fix it and where the guidance comes from.
Four severities
- Blocker — the planner cannot responsibly issue a build package. Change the design or get a professional review.
- Warning — a material safety or buildability concern. Shown prominently; some can be acknowledged with a note.
- Advisory — a better welfare, comfort or maintenance practice. Never blocks an export.
- Info — an assumption or educational note, recorded in the package.
What the rules look at
- Enclosure: mesh opening and gauge, gaps at the base, roof and wall junction.
- Access: self-closing doors, latches cats cannot nudge, vestibules for escape-prone cats, room to clean.
- The house: dryer and appliance vents, meters, egress windows and utilities inside the enclosure.
- Weather: shade and cover in hot climates, mesh roofs under heavy snow, drainage.
- Ground and predators: dig-proof skirts on soil, a fully enclosed roof.
- Welfare: resting and hiding places, several heights, two routes in multi-cat homes, ramps for seniors, water.
- Plants: known hazards and plants with insufficient data within chewing reach.
Guidance, not certification
A clean report reads “No issue detected by the current rules” — never “safe” or “approved”. Local building codes, HOA and landlord rules, engineering, electrical, fire-safety and veterinary decisions stay with the people responsible for them. See how the checks work and the full rule list.
The dryer vent on the host wall would discharge into the catio. Move the catio, or reroute the vent outside it with a qualified installer.
The selected 2 × 4 in fence mesh lets small cats through. Use 1 × 1 in or 1 × ½ in welded wire.
A door that can be left ajar is a common escape route. Add a self-closing hinge or spring, or a vestibule.
With three cats, a dead-end perch lets one cat block another. Add a second route.
Cost range uses catalog price ranges from the date shown. Check local prices before buying.
In the beta
- Versioned rules with sources and review dates
- Blocker / warning / advisory / info severities
- Acknowledgements with notes where a rule allows them
- Cat profiles (age, mobility, escape risk) that tune welfare advice
Questions
If the checks pass, is my catio safe?
It means no issue was detected by the current rules — which cover common, well-documented risks. They cannot see your cats’ behaviour, the condition of your wall, or local rules. Inspect the build before use and watch your cats closely at first.
Where do the rules come from?
From published feline-welfare guidance, plant-toxicity references, manufacturer instructions and experienced builders. Each rule records its source, evidence type and review date on the rules page.
Related
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Free to design and check. Fit a catio to your wall, window and yard, run the safety checks, and see the materials list before you buy a single board.