Can you build a fourplex on a Markham lot in 2026?In March 2026, Mayor Frank Scarpitti used strong mayor powers to revoke a council-approved plan that would have allowed up to four units on most residential lots. Ontario law still allows up to three residential units on many urban residential lots, such as a main home plus a basement suite and a garden suite, subject to zoning standards, permits and the Building and Fire Codes. Check your lot before you plan.
Headlines about the veto left many owners unsure what is allowed. The short version: four units as of right did not happen, but more than one unit on a lot often can.
Michael John Lau, a REALTOR® with the Kaizen Real Estate Team, one of the most active real estate teams in Markham and York Region, helps buyers and owners understand the potential of a lot before they invest.
What happened
- Council approved a plan, 7 to 6, to allow up to four units on most residential lots.
- In March 2026, the mayor revoked it using strong mayor powers, citing transportation, parking and service capacity.
- Reports said federal Housing Accelerator Fund money tied to the plan could be at risk.
What is generally allowed
| Option | What it usually involves |
|---|---|
| Basement or second suite | A self-contained unit inside the house, with permits |
| Garden suite or coach house | A detached unit in the rear yard, where lot size and setbacks allow |
| Up to three units total | Under provincial rules, on many urban residential lots |
Zoning By-law 2024-19 includes rules for additional residential units. Lot size, setbacks, height, servicing and access decide what fits.
Common deal breakers
- Not enough room for a garden suite after setbacks
- Utility and servicing capacity
- Fire separation and egress costs for a basement unit
- Heritage, tree or conservation limits
Buying a lot with suite potential?
Michael John Lau can help you check zoning and feasibility questions before you offer.
Book a buyer consultationSearch Markham homesPrefer to talk? Call the Kaizen Real Estate Team at (647) 370-8885.
Steps before you build
- Check your zone and request a zoning search.
- Talk to a designer about a feasibility plan.
- Get building permits for each unit.
- Budget for servicing, fire separation and parking where required.
Watching for change
Housing policy is moving quickly. Follow Markham council and provincial announcements before you buy for future units. Ultimately, the decision is yours. The goal is to make sure you have all the information before you plan.
Know the rules before you plan the units. Call the Kaizen Real Estate Team at (647) 370-8885 or book a consultation.
Frequently asked questions
Can I build a fourplex in Markham?
Not as of right. The March 2026 veto revoked the plan for four units on most lots.
How many units can I have on my lot?
Ontario allows up to three on many urban residential lots, subject to zoning and permits.
Can I build a garden suite in Markham?
Possibly, where lot size, setbacks and servicing allow.
Do I need permits for a basement unit?
Yes, and it must meet Building and Fire Code requirements.
Why did the mayor veto the plan?
He cited transportation, parking and municipal service concerns.
Could the rules change again?
Yes. Housing policy is changing quickly, so check before you buy.
Michael John Lau and Neeraj Moolchandani are licensed REALTORS® with the Kaizen Real Estate Team, eXp Realty, Brokerage, 9763 Markham Rd, Markham, ON L6E 1A4. Licence #4784577. Call (647) 370-8885. The veto details are from Global News (March 12, 2026) and Real Estate GTA Today (March 14, 2026). Additional unit rules are general provincial rules; confirm your lot's standards with the City of Markham. This article is general information only and is not financial, legal or tax advice. Not intended to solicit buyers or sellers currently under contract with another brokerage.
