Cat Highways · Chapter 3

Pick Your Pieces

Price every piece, then compare honestly: building can cost more than the cheapest bought set and still be the better buy.

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Opens on the book's two shopping lists. Change any quantity or price to your own and press Calculate.

Part A, the wall highway

Part A, the wall highway: quantity and unit price
MaterialQtyUnit price
1x12 x 8 ft pine board
1x4 x 8 ft pine board (slats)
heavy-duty 10 in steel bracket
standard 6 x 8 in bracket (post top)
4x4 x 8 ft Douglas-fir post
5/16 in structural screws, box of 45
#8 x 5/8 in screws (say)
1/4 in eye bolts, 2-pack
1/2 in sisal rope, 100 ft
fence staples, 1 lb
indoor-outdoor carpet, sq ft
T50 staples
wood glue, 16 oz
water-based polyurethane, quart

Part B, the window catio

Part B, the window catio: quantity and unit price
MaterialQtyUnit price
2x2 x 8 ft, untreated (box and door)
pressure-treated 2x2 x 8 ft (legs)
3/4 in sanded plywood, 2 x 4 ft (floor)
1 x 1 in 16 ga welded mesh, 36 in x 50 ft
exterior screws 2 1/2 in, 5 lb
fence staples, 1 lb
hinges, pair
hook and eye
barrel bolt

Bought instead

Each piece, for cost per piece and per meter

Enter your prices and press Calculate.

The formula

  • Line total = quantity × unit price; the part's total is the sum of its lines
  • One step = board price × (step length ÷ board length) + 2 brackets + 4 structural screws (box price ÷ screws in the box each)
  • Cost per meter of route = cost of the piece ÷ its length in meters
  • Bought equivalent = 2 three-step sets + a bridge + a shelf + a post
The book's worked example, Chapter 3. Part A comes to 373.37 and Part B to 227.10: 600.47 for both. A budget bought set doing Part A's job is 200.00, so the build costs 173.37 more; a maker-built set is 492.00, so the build saves 118.63. One step is 31.83 in materials, 69.61 per meter of route; the window catio costs 77.10 more than a bought box, with 41 ft of mesh left on the roll.

A bought set's price leaves out fitting it; the build's price leaves out your time and any tools you buy (about 153 for the book's list). Metric first, imperial beside it. Prices are illustrative US home-center prices from November 2026, shown without a currency sign; put in your own. Everything stays in your browser: no sign-up, nothing stored.