Home builders handle projects bigger than a typical renovation crew usually takes on: full custom builds, whole-house rebuilds, major additions that change the footprint of a property, and gut renovations that touch structure, mechanicals, and layout all at once. In Markham, that often means working within specific lot and setback rules in older neighbourhoods like Thornhill or Unionville, alongside newer subdivisions where builders coordinate closely with the city's permitting and inspection process. We've profiled 6 home builders serving the area, ranging from small design-build teams to larger operations with in-house project management.
What to check before you hire
A home builder should carry proper licensing and insurance (liability and WSIB coverage for any workers on site), and be willing to show you a portfolio of completed projects similar in scope to yours, not just renderings. Ask how they handle permits, who pulls them, and who's responsible if an inspection fails. Get a written contract that spells out payment schedules tied to project milestones, not just dates, and confirm whether the quote is fixed-price or cost-plus. Warranty coverage matters too: in Ontario, new home builds typically fall under Tarion warranty rules, and it's worth confirming whether your project qualifies and how the builder handles that paperwork.
How we score builders
Our rankings weigh licensing and insurance, verified customer feedback, responsiveness, project history, and how clearly a company communicates pricing and timelines. The full breakdown of how we weight each factor is on our methodology page. For a side-by-side comparison of all 6 Markham builders ranked against these criteria, see our best renovation contractors in Markham guide.
