Newmarket Property Guide · Updated for 2026
Buying, owning or renovating a home in Newmarket involves Town of Newmarket rules, York Region requirements and Ontario law. This guide brings together the main property issues worth checking before you buy, renovate or create another dwelling unit.
Property Taxes in Newmarket
Newmarket property taxes are calculated using the applicable tax rate and the property’s assessed value. The Town collects municipal, York Region and education portions through the property-tax bill. Newmarket’s official tax information includes the 2026 property-tax rate schedule and explains supplementary assessments that can follow additions, renovations, new construction or changes in property classification.
Use the Ontario Home Intel Property Tax Calculator for planning, then verify the actual account, assessment and current rates through the Town of Newmarket property-tax page.
Building Permits and Renovations
Newmarket states that most renovation, alteration, construction and demolition projects require a building permit before work begins. Examples include structural alterations, finishing a basement, creating an additional residential unit, additions, certain decks and accessory structures, below-grade entrances, plumbing or HVAC alterations and new or enlarged openings.
The Town also requires a Zoning Preliminary Review before certain permit applications, including additional residential units, additions, decks, sheds, pavilions, gazebos, demolition and new construction. Review the Town’s building and renovating guidance before starting. See our Ontario renovation guides and Zoning & Permits hub for broader context.
Additional Residential Units in Newmarket
Newmarket permits additional residential units subject to zoning, building and registration requirements. The Town’s current guidance allows up to three units on a qualifying property in certain configurations, such as a primary unit with two ARUs or a primary unit with one internal ARU and one detached ARU. Property-specific zoning and servicing requirements still control what can actually be built.
New ARUs must proceed through the building-permit process and then registration. Newmarket’s registration process calls for items such as a final building inspection report, Electrical Safety Authority compliance documentation and parking information. Existing units have different documentation requirements depending on when they were created.
Check the Town’s ARU registration guidance and our Additional Rental Units in Ontario guide.
Newmarket Property Due-Diligence Checklist
- Confirm the property’s current zoning and permitted uses.
- Review permit history for finished basements, additions and structural alterations.
- For an existing ARU, check municipal registration and permit status.
- Verify the current property-tax account and MPAC assessment information.
- Confirm parking, servicing and site-specific requirements before relying on additional-unit potential.
- Check whether other approvals or applicable law affect the proposed work.
Useful Ontario Home Intel Resources
- Buying a Home in Ontario
- Ontario Property Taxes
- Buying a House With a Basement Apartment
- Basement Renovation Permits
- Ontario Municipal Property Guides
Newmarket Property FAQ
Do I need a permit to finish a basement in Newmarket?
Newmarket lists finishing a basement among projects requiring a building permit. The exact submission requirements depend on the scope of work.
Can a Newmarket property have three dwelling units?
Up to three units may be possible on qualifying properties under the Town’s ARU framework, but zoning, servicing, parking, building-code and property-specific requirements must be confirmed.
Do Newmarket additional residential units need to be registered?
Yes. Newmarket maintains an ARU registration process, with different supporting requirements depending on whether the unit is new or existing and when it was created.
Ontario Home Intel is an independent educational resource and is not a real estate agency or brokerage. Information is general only and is not legal, planning, tax, engineering or other professional advice. Municipal requirements can change; verify property-specific requirements with the Town of Newmarket and other applicable authorities before acting.