Compare ADU costs
Side-by-side on the same six-phase ledger. Figures match the published posts — pick any two builds.
| Phase | 800 | 400 | Diff |
|---|---|---|---|
| Soft costs | $32,000 | $28,000 | −$4,000 |
| Site work + foundation | $38,000 | $26,000 | −$12,000 |
| Framing + structure | $48,000 | $26,000 | −$22,000 |
| Building envelope | $42,000 | $25,000 | −$17,000 |
| Systems + interior | $147,000 | $102,000 | −$45,000 |
| Landscaping & hardscape | $13,000 | $8,000 | −$5,000 |
| Total | $320,000 | $215,000 | −$105,000 |
| Per sq ft | $400 | $537 | +$137 |
Half the size. Two-thirds the cost. Fixed costs — permits, the sewer connection, the kitchen, the bathroom — do not scale with floor area.
Soft-costs-only is not a full build, so it is not a compare column. Download the blank ledger on theworksheetpage, or readwhy the six phases exist.