What did the City's ADU grant pay?
A lot, while it was open. The City describes it as a grant to help with the costs of Additional Dwelling Units or Garden Suites within, or on the same property as, new or existing low-density houses
. Since October 9, 2025: The value of the Grant is 70% of Eligible Costs, to a maximum of $40,000 per Eligible Unit(s).
It paid in two advances, the first of 20% based on a contractor's estimate for total Eligible Costs
and the rest when the occupancy permit was issued (City of Hamilton, Housing Accelerator Fund, read November 5, 2026).
| Payment | Amount | When |
|---|---|---|
| First advance | 20% of the estimated grant, up to $8,000 a unit | Early, from a contractor's estimate of eligible costs |
| Second advance | Up to 70% of actual eligible costs, less the first advance | When the occupancy permit is issued |
| Total | No more than $40,000 a unit | Across the two advances |
Is it open now?
No. The City: The Additional Dwelling Unit and Multi-Plex Housing Incentive Program has reached its allocated funding capacity, and the application portal is now closed to new submissions.
And: we are unable to accept new applications, grant extensions, create a waitlist, cancellation list, or make exceptions to this closure.
(City of Hamilton, Housing Accelerator Fund, read November 5, 2026) If the City reopens it or starts a new program, it will be on that page.
What about the backwater valve grant?
Not while adding a unit. Hamilton's Protective Plumbing Program grant of up to $2,000 lists, among its conditions, You are not currently in the process of adding a secondary dwelling unit.
(City of Hamilton, Protective Plumbing Program, read November 5, 2026) The program itself is explained in the backwater valve grant.
What still lowers the cost?
Choosing the cheaper kind of unit for your lot, and getting the plan right before the permit. The City's permit fee for an ADU is a flat $515 inside the house or $1,030 detached, set out in what a building permit costs; the differences between the two kinds are in basement unit or garden suite. JDT Construction Inc. draws the unit on your own property and prices the whole job in one written proposal before you commit; see the ADUs page.