Cat Hack: Penthouse for Mr Pluto


Materials required
Cat, suitable window, Billy bookcase, squares of non-slip rug underleys (gray squares in pics), cushion with ties on one side (colour MUST complement cat’s colour!) sheet wood for penthouse platform about 400 x 400 mm, wood spacer to lift outside of penthouse platform to about level – I used 75 x 50 x 800mm,
6 50mm selftapping wood screws, 6 tacks to fix platform sheet wood to spacer & window sill

Tools needed
Drill, hole saws to cut rounded corners of step holes, Jig or saber saw,

Find a suitable window or unused glass door. The hack does not block the view.


You will need 3 to 5 shelves plus the top and base for most cats. Mr Pluto is 80cm long not counting his tail so as he grew we discarded shelves. Store discarded shelves on the base. As cats age or put on weight, they may need an extra “gentleman’s or lady’s step”

Penthouse detail

Plan the step holes from top down – alternate left to right to left etc.
Note that the top hole should be opposite the spot where Mr Pluto’s red cushion is to be placed.
Leave half of the shelf width for strength when cutting the step holes. For 300m deep shelves, leave 150mm. This gives a step hole of 300mm x 200mm if the bookcase is 50mm out from the glass. If you can’t have the bookcase out 50mm, just have the step holes on the room side of the shelf. (Mr Pluto has the step holes on the glass side)

1. Make sure bookcase will fit window.
2. Remove back from bookcase. This provides bracing so when assembling, you will need to attach the bookcase to the window or doorway frame.
3. Mark out step holes as rectangles. Mark where the hole saw’s drill needs to go inside of the corners.
4. Cut holes, sand down the cut edges.
5. Cut hole in top of bookcase as last step hole to penthouse.
6. Put bookcase in place.
7. Put one or two screws through bookcase upright into side of window sill/ door jam to secure and brace bookcase.
8. Add shelves.
9. Add spacer timber and penthouse platform.
10. Tie pillow to nails driven into top side of upper window sill.
11. Add the non-slip rug underlays to shelves.
12. Add cat.

Jules Yap