The shed designer opens with a gallery of eleven ready-made sheds under 100 sq ft: the cheapest, the most room per dollar, the best looking, one to match a HardieBoard house, a barn, and so on. A design search picks every card. It builds, prices and checks each design, and nothing is typed in by hand.
Until now, though, nobody had checked the picks from outside. The project has an independent audit (paretoaudit.mjs). It takes a design, changes one setting at a time, and asks whether any change gives a cheaper shed with the same room and the same looks score. The starter presets were already held to a 3% gap. This week the gallery cards joined them. Each card is held to the gallery's own rules: every member stays at 90% of capacity or less, and the card keeps its size.
What the audit found. One card failed outright. The "Barn for storage" card is a 7x14 gambrel, and it had 2x6 floor joists where 2x4s pass at 67% of capacity. That alone is $98 at our dated prices. The cause is how the card is chosen. It takes the most room per dollar among all the barns the search kept, not just the barns on the search's Pareto front. The search's final polish, which tries lighter framing, only ever touches front designs, so it never reached this one.
The fix. Each card's design now gets the same treatment before it is shown. It takes, one at a time, any change to the joist size or spacing, the rafter size or spacing, or the subfloor panel that makes it cheaper without losing room or looks, as long as it still passes every check at 90% and draws with no warning. On the regenerated gallery:
| Card | Before | After | Saved |
|---|---|---|---|
| Barn for storage 7x14 | $3,251 | $3,014 | $236 |
| Cheapest lap-sided 7x12 | $2,960 | $2,878 | $82 |
| Most storage 9x11 | $3,324 | $3,268 | $55 |
| Best looking 9x10 | $3,375 | $3,319 | $55 |
| Mower shed 10x10 | $3,712 | $3,657 | $55 |
| Most room per dollar 8x12 | $2,858 | $2,817 | $42 |
| Long 6x16 | $3,418 | $3,376 | $42 |
The other four cards were already as cheap as one change could make them. Most of the smaller savings come from the same swap: an OSB subfloor in place of plywood. Both are rated for the joist spacing used here, and the subfloor isn't part of the looks score. The barn also went to 2x4 floor joists and rafters at 24".
Fresh prices on every deploy. The cards used to be regenerated by hand. Prices in the tree change most days, so the committed cards drifted: on main this morning, the cheapest card's "when it ran" price was $9 off. The deploy workflow now runs make-gallery.mjs before it builds the site, so every deploy searches with that deploy's prices. The search takes about 50 seconds. The committed copy remains for tests and for anyone running the page from a checkout. (For a few hours it ran as one of the build's own generators instead. That made the site build rewrite a committed file while the test suite was building the site in parallel, and a determinism test caught the race. Generators now write only files that are never committed.)
All prices are materials before tax, from the dated listings in the tool's price table. They are estimates, not quotes, and the designs are not engineered or code-checked.