About Square Plumb

Give it the size of the building, the roof, and where the door and windows go. It works out the rest: every board, every cut, every nail, the order to build in, and what it costs.

Derived, never stored

A complete building is about 1.3 KB of declared inputs. Every board, every cut length, every nail and every step of the build order is regenerated from those inputs each time. Nothing is saved that could disagree with anything else, which is why the price on screen is always the price of the building on screen.

It refuses rather than guesses

Where a span, a pitch or a placement will not work, the model says so and names the rule and the number — it does not quietly draw a member no yard sells. A check that cries wolf gets ignored, so each one asks a single question.

Accessibility

These pages are built to WCAG 2.2 AA. The builder itself is a 3D canvas, and we will not claim it is operable by a screen reader — it is direct manipulation of geometry, and pretending otherwise would be worse than saying so. What we do commit to: the controls around the canvas are keyboard operable and labelled, and everything the model means is available as text — the cut list, the fastener schedule, the build order and the materials estimate are the same information the picture shows, in words, on every plan page on this site.

If something here does not work for you, that is a defect. Tell us.