Lean-to catio
The classic catio: a frame against the house, high side on a ledger at the wall, roof sloping to a lower front. Cats come and go through a window or a cat door; people come in through a front door to clean.
Why lean-tos are popular
Sharing the house wall saves a whole side of framing and mesh, gives shade for part of the day, and puts the catio where the cats already are. Access can be as simple as a window they already use.
What to get right
- The wall junction. The gap between ledger and siding is the classic escape route. Seal it, and do not trap water behind the ledger.
- What is on the wall. Dryer and appliance vents must never discharge into the enclosure; meters and utilities need access. The planner checks these against your wall.
- The roof. A partial cover gives shade and a dry corner; a full mesh roof is simplest but lets snow and leaves in.
- A door you can walk through for cleaning — and a latch that a cat cannot nudge open.
Plan
Front elevation
In the planner: Attached lean-to
| Starts at | 8 ft × 4 ft × 7 ft high |
|---|---|
| Depth | 2 ft – 9 ft 10 in |
| Height | 3 ft 11 in – 8 ft 10 in |
| Front height | 2 ft 11 in – 8 ft 10 in |
| Width | 2 ft 11 in – 19 ft 8 in |
Sizes outside these limits fall back to concept-only.
In the beta
- Lean-to template with ledger, sloped rafters and roof options
- Wall openings, vents and utilities checked against the enclosure
- Human door, cat door and vestibule options
Questions
Do I need a permit for a lean-to catio?
It depends on where you live, the size, and whether it attaches to the house. Ask your local building department, and check HOA or landlord rules. The planner does not give permits or code approvals.
Can I attach it to vinyl siding?
The ledger should fix through to the wall structure, not just the siding. If you are not sure what is behind your siding, the planner flags structural attachment for review.
Related
Design your catio in your browser
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.