Build Your Own
Cat Tree

They're so easy to make and will provide endless fun and a safe place to sleep for your cat(s).  You can build a Cat Tree with as many levels (or as few) as you'd like, adding onto the sides of the tree or building out onto the front or the back.  The above tree could have had additional platforms on the front, simply by adding a couple of 2x4s and another piece of plywood.  You can custom-create your own tree!

To create the cat tree above, you will need:

saw
screws
screwdriver (preferably automatic)
plywood (thick)
2x4s
some old (or new) rope
cat toys that will dangle well
kite string (to hang toys from)
carpet remnant, chair cover, fabric or blankets (for padding/cover)

Step 1: Begin by using a very sturdy base (this can be thick plywood, very cheap at home stores) or, as we used, an old cabinet top.

Step 2: Measure 2x4s to the height you wish to have them, two 2x4s for the tallest part of the structure (see part that gray cat is on) and one for the shorter platform (see where green carpet is). 

Step 3: Using two screws each (NOT NAILS), affix the bottoms of the 2x4s to the base of your cat tree, leaving approximately two inches on either side of where the upper platform will sit.  This provides the utmost stability.

Step 4: Measure between the 2x4s and create two "shelves" for further stabilization.  (Remember, cats exert a lot of weight when they jump!)  Screw the 2x4 slats between the upright 2x4s, using two screws for each end of the 2x4 (see above).

Step 5: Add the third 2x4 at the height you desire.  Screw it into the base with two screws.

Step 6: Cut your platforms to desired size.  Be sure they're smaller than the base!

Step 7: Screw the platforms down to the 2x4 tops, being sure to use two screws per 2x4 and ensuring that there is no exposed screw left for kitties to become injured on.  On the lower platform, screw the side of it to the taller 2x4, for extra stability.

Step 8: Now comes the fun part.  You've built your cat tree, now you get to make it comfortable, pretty and fun!  Using carpet from a remnant store (or square chair covers, or anything else that works...be creative!) attach a soft sleeping area for your cat(s) on each of the platforms.  Make sure it isn't too fluffy, as they may be afraid to jump on something excessively squishy.

Step 9: Use some old (or new) rope to cover the exposed 2x4 wood and create a great claw/paw scratching post out of each upright piece of wood.  They will love this part!

Step 10: Make it their own.  Attach fun toys, top with favorite blankets, tack pictures of the kitty(s) onto the wood, whatever makes it home!

Cat trees can be stained or painted, but be sure to leave them outside for a good while (out of the rain) until they've dried and the scent has subsided.  Kitties have sensitive noses and will not play in stinky trees.  Preferably, cat trees should be decorated by using rope (fastened tightly to the wood) or by putting up pictures or fabric swatches.  Natural wood is always best.

Enjoy your Cat Tree!