How a garage conversion calculator works — one garage feeds many trade calculators into one list
A composer never re-implements math. You describe the garage once, and the shared inputs feed the standalone trade calculators — framing, insulation, drywall, subfloor, flooring, paint & trim, egress windows, HVAC. Each runs on its own, then the outputs merge into one list where every line traces back to its source calculator.
What this diagram shows
A flow diagram of the garage conversion composer. On the left, the garage is described once — its size, the scope (bonus room, habitable room, or ADU), the climate zone, the slab slope, and whether a bedroom is being added. Those shared inputs are fed to eight standalone calculators listed in the middle: framing for the garage-door infill and partitions, insulation for the walls and ceiling to the IECC minimum, drywall including 5/8-inch Type X on the ceiling, a subfloor system of sleepers over the slab, flooring, paint and trim, an egress window per bedroom, and the HVAC load added to the system. Each calculator runs independently and produces its own quantities, and on the right those outputs merge into one materials list where every line is tagged with the calculator that produced it. The composer never re-does the math — it calls the same calculators you can use on their own and combines their results.
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Garage Conversion Calculator
Live garage conversion cost — bonus room, habitable, or full ADU. Egress, mini-split, foundation, service upgrade adders. IRC/IECC callouts. Free.
