How Long Until This ADU Is Finished?

2 min readWritten lesson

The frame went up in weeks — why does the rest take months? The second-half timeline, its real bottlenecks, and how to read schedule health.

Standing in a framed ADU (lessons 12.5–12.6), every homeowner asks the same question: "So… another month?" The honest answer: the frame is roughly the one-third mark. From here, expect 3 to 5 months for a detached unit. This lesson explains where that time goes — because knowing it is the difference between watching a healthy project and suspecting a stalled one.

Why the second half is slower — three structural reasons:

1. The trades multiply and must take turns. Framing was one crew doing one thing. Now: plumber, electrician, HVAC installer, roofer, insulator, drywaller, tile setter, cabinet installer, painter, flooring crew, finish carpenter — each a separate schedule, each dependent on the last, most juggling other jobs. A two-day gap between each of ten trades is nearly a month of calendar, with zero laziness anywhere.

2. Inspections gate the sequence. Rough systems can't be insulated until inspected; insulation can't be drywalled until inspected (12.11's system at work). Each gate adds days — properly, since covering unverified work is how disasters hide.

3. Materials run on their own clocks. Cabinets: often 4–8 weeks from order. Windows (already handled if the GC ordered early — 12.6's lesson). Specialty tile, fixtures on backorder. A good GC orders long-lead items at permit; a schedule dying of cabinet lead time in month five reflects a decision made in month one.

Reading schedule health — ask these, not "when's it done?": What's the next inspection, and when is it scheduled? (A project always aimed at its next inspection is moving.) What are the current lead-time risks? (A GC with an answer is managing them.) What decisions are you waiting on from me? (The most common hidden bottleneck is the homeowner's own unmade finish selections — lesson 6.7's allowances becoming urgent. Decide early; decide once.)

And the number to hold: from permit issuance, the full construction of a detached ADU lands near lesson 12.1's 5–9 months. From today's framed milestone: 3–5. Garage conversions compress everything. Now — what are those trades actually doing in there? Next lesson.

Key takeaways

A framed shell is the one-third mark: 3–5 more months is normal for detached units.
Trade sequencing, inspection gates, and material lead times — not laziness — consume the second half.
Long-lead items (cabinets, windows) must be ordered at permit, not when needed.
Track health by the next scheduled inspection and your own pending decisions, not by asking "when's it done?"