Basement Apartments & Secondary Suites in Markham, Ontario
Markham allows three units on most lots — not four, despite what you've read. It also still requires parking for a suite, unlike Toronto. The real rules, fees and rents.
Markham permits up to two additional units on a lot — three units in total — where single-detached, semi-detached and townhouse homes are allowed. It does not yet permit four; that change was never enacted. Unlike Toronto, Markham still requires a parking space for a secondary suite, and there is no municipal grant.
HouseLyft helps homeowners in Markham, Ontario work out what their lot legally permits, what a suite will cost to build, what it should earn, and which programmes actually apply — then connects them with a vetted builder.
If you’ve compared “garden suite by city” pages, Markham looks like its GTA neighbours. On two points that decide a project, it isn’t.
First, the unit count. You may have read that Markham allows four units as-of-right. It does not. Markham’s own page describes four units as something “the City is proposing” — a change Council directed staff to prepare in December 2023 that has not been enacted. Markham sits at the Planning Act baseline of three units total. Any competitor page quoting four as-of-right units for Markham is citing a plan, not a rule. (Separately, CMHC found Markham non-compliant with its federal housing commitments on April 2, 2026 and cut $7.36 million from its funding — the four-unit initiative is part of that same un-delivered plan.)
Second, parking. Toronto removed minimum parking city-wide; Markham did not. A secondary suite here still needs its own space.
What Markham permits on a residential lot
Up to two additional residential units — three in total — on a lot zoned for a single-detached, semi-detached or townhouse home, under Zoning By-law 2024-19. Additional units are not permitted in some environmentally sensitive areas, so a property’s specific zone has to be checked.
The provincial statute that allows this also delivers the one real financial benefit: a second and third unit are exempt from development charges, so a Markham homeowner generally pays $0 in DCs on the added units. There is no cheque and no municipal grant — that exemption is the whole of it.
3 in totalUnits permitted
NoneMunicipal grant
$1,996/mo2-bed average rent
The parking rule that catches people out
Markham has not waived parking for additional units. The published standard:
- One space for the house plus one for a secondary suite
- One more again if you add a coach house or garden home (three units, three spaces)
- Each space at least 2.75 m × 5.8 m, entirely on the lot — street and lane parking do not count
On a narrow lot, finding that second or third legal space is often the constraint that decides whether a suite fits at all.
Detached units: two types, both small
Markham splits detached units by whether the lot has a rear lane:
- A garden home (no lane) is capped at 15 m² of floor area on a lot of 500 m² or less, rising to 60 m² above that, with a 4.0 m height limit. Fifteen square metres is smaller than many single-car garages.
- A coach house sits above a detached garage and requires lane access. It can reach two storeys and 8.0 m, with lot coverage the greater of 15% or 40–60 m².
A property may have one or the other, never both. This is why rear-lane neighbourhoods like Cornell, in northeast Markham, are among the few places the larger coach house is buildable — everywhere else, the far smaller garden-home standard applies. Whether your street has a lane changes what you can build.
What the City charges
Markham prices building permits by rate, not as a flat total, under By-law 2025-121:
- Secondary suite (a unit inside the existing home): $22.08 per m², with a minimum permit fee of $151
- Plumbing fixtures at $22.35 each, subject to a $250 minimum
- A mandatory registration and inspection with Markham Fire & Emergency Services also applies; the City confirms a fee but does not publish the amount
If you find a page quoting $21.03 per m² or the label “Accessory Apartment,” that’s the superseded pre-2026 schedule — Markham renamed the row “Secondary Suite” and raised the rate.
What a Markham suite earns
As of CMHC’s October 2025 Rental Market Survey, average rents in Markham were $1,885 for a one-bedroom and $1,996 for a two-bedroom, with an all-bedroom-type average of $1,942.
Two caveats that matter for a development decision: these cover the primary rental market only — purpose-built rentals — and exclude condominium and secondary-market units, which typically rent higher in Markham. Studio data is suppressed by CMHC for the city. It’s a small, expensive rental pool: Markham had roughly 90,500 owner households against 20,300 renter ones in 2021, which is the demand-side case for adding a suite.
What we do — and what we don’t
HouseLyft establishes whether a project stands up before anyone spends money on drawings: what your lot permits under the current by-law, what the build realistically costs, what it should rent for, and which programmes genuinely apply. Where it works, we hand you to a vetted builder and stay involved. Where it doesn’t, we say so.
We are not a lender and we do not sell mortgages.
One correction worth carrying, because it is still advertised widely: the federal $80,000 Secondary Suite Loan was cancelled in Budget 2025 and never launched. Our financing guide sets out what is actually live.
Serving Markham and the surrounding region
We work across Markham and the wider GTA, including Vaughan, Richmond Hill, Toronto and Mississauga — where the unit counts, parking rules and programmes differ materially from Markham’s. The full list is on our service areas page.
We also handle multiplex conversions and planning and permits across York Region.
Common questions about Markham suites
Not as-of-right. Four units is a proposal Markham has directed staff to prepare, not an enacted rule. The current limit is three units total — two additional units plus the main house.
Yes. Unlike Toronto, Markham still requires one space for the house and one for the secondary suite, each at least 2.75 m × 5.8 m and located on the lot — not on the street or lane.
No. A homeowner incentive was part of Markham’s federal housing plan but was never delivered. The only financial benefit is the province-wide development-charge exemption, which makes DCs $0 on the added units.
It depends on lane access. A garden home (no lane) is capped at 15 m² on a lot of 500 m² or less; a lane-accessed coach house above a garage can reach two storeys and 8.0 m.
A secondary suite is charged at $22.08 per m² with a $151 minimum, plus plumbing fees and a Markham Fire registration fee the City doesn’t publish. The total depends on the suite’s size.
What people repeat — and what the rule says
A Markham suite permit is $21.03 per m².
It is $22.08 per m², under the row now called “Secondary Suite”.
Any page quoting the old rate or the label “Accessory Apartment” is working from the superseded pre-2026 schedule.
How this page was checked
Verified 20 July 2026, claim by claim — every figure above traced to the instrument it comes from.
Municipal rules and fees change — confirm current terms with the City of Markham before committing to a project.
Find out what your Markham lot allows
Enter your address and we’ll come back with what your property permits under the current by-law, what a suite would realistically cost, what it should earn, and which programmes apply to you specifically.
- What your lot allows
- What it should earn
- Which programmes apply
Illustrative — your report is built from your own address.