How long it actually takes, stage by stage.
Total timelines already live on other pages. This breaks that total down by stage, so you know where the time actually goes. These are planning estimates, not a contract: your property and municipality decide the real number.
Where the weeks actually go.
- 01How busy is the building department?
- 02Is the application complete the first time?
- Feasibility check1 wk
- Permit drawings3 wk
- Permit review6.5 wk
- Approval to start1 wk
- Construction8 wk
- Start
- Apr
- Weeks
- 20
- Ready around
- Aug
Planning estimates, not a contract. Stages are shown end to end; some overlap in practice.
How long does an ADU take?
Roughly 3–5 months for a basement apartment and 6–12 months for a garden suite, from design to occupancy.
Basement apartment
Garden suite
See where the time actually goes.
These are planning ranges. Your municipality, property and project scope can move the schedule. Review, highlighted, is the widest range on the page.
Roughly 3–5 months
- 01Feasibility checkProperty and code reviewAbout 1 week
- 02Permit drawingsFull drawing set2–4 weeks
- 03Permit review15-day Code clock, plus comments3–10 weeks
- 04Approval to startFinal permit issueAbout 1 week
- 05ConstructionInterior build6–10 weeks
Some stages overlap in practice. Busier building departments can push review toward the top of its range or beyond.
Roughly 6–12 months
- 01Feasibility checkLot, zoning and servicing1–2 weeks
- 02Drawings + servicing planBuilding + servicing4–8 weeks
- 03Permit review10-day Code clock, plus comments2–16 weeks
- 04Approval to startFinal permit issue1–2 weeks
- 05ConstructionFoundation, framing, services, finishes16–28 weeks
New construction has stages that can’t overlap: you can’t frame before the foundation cures, and servicing is inspected before it’s covered. That’s why a garden suite is measured in seasons, not weeks.
Totals aren’t simple addition.
Drawings, consultant work and contractor planning can sometimes move in parallel, and finishing touches on drawings can happen while early review comments come back. That’s why the total can be shorter than every stage added together.
How long does permit review take?
Once the application is complete, the Building Code gives the department 15 business days to issue or refuse a permit for a house with a basement suite, and 10 for a detached garden suite (Division C, Table 1.3.1.3). Each round of review comments adds time on top, which is why a complete, clear first submission matters most.
A complete application
Missing information is the single most common cause of delay, not a difficult reviewer.
Drawings built for the reviewer
Drawings that anticipate the review comments a specific municipality tends to raise, not a generic package.
Timing
Filing when a building department isn’t backlogged. It varies by season and by each municipality’s current workload.
We’ll give you a realistic review-time estimate for your municipality at the feasibility stage, based on what we’re currently seeing there.
Reduce avoidable waiting.
Confirm feasibility first
Before drawings. Don’t design a project that zoning, height or servicing can’t support.
Keep decisions moving
During drawings. Quick decisions stop small design questions holding the set.
Submit a complete package
Before submission. Missing documents create avoidable delays.
Answer comments quickly
During review. Fast, clear revisions keep the permit moving.
Pick the question closest to yours.
Our Process
The same stages, told step by step.
Does my property qualify?
A self-check on space, lot rules and servicing before you call.
Cost & Financing
What it costs all in, and how homeowners pay for it.
A realistic timeline for your address.
For your specific property and municipality, not a generic one.