Home additions

The 10 Best Home Addition Contractors in Markham, ON

Updated 132 firms checked10 ranked

This list ranks 10 home addition contractors in Markham, ON. It starts from Google Maps searches for home additions and related building work in Markham: 132 firms were checked, and building and renovation firms with their own website and an open Google listing went forward. Firms are weighed on their Google rating, the number of reviews behind it, how closely their services match home addition work, and their portfolio. The strongest firm overall sits at place 1, places 2 to 3 carry a badge for what each suits best, and places 4 to 10 run in order. Ratings and review counts are Google's, checked October 14, 2026. How we rank

Canadian Constructor Creations

Best overall

Toronto and GTA design-build firm doing full-home renovations, basement conversions, bathrooms, kitchens and additions for homes and commercial clients.

Updated

Why it ranks here

  • Has over 20 years of industry experience, spanning low-rise and high-rise construction.
  • Offers a 5-year warranty, as stated on its homepage.
  • Works as a design-build and renovation company on houses and commercial projects across Toronto and the GTA.
  • Prepares complete architectural plans and drawings, with construction engineers and architectural engineers among its staff.
  • Builds houses, carries out complete house renovations and converts basements into residential units.
  • Portfolio work includes full home renovations in Newmarket, Scarborough and on Bloor Street in downtown Toronto.
Home additions · Full home renovations · Basement conversions · Bathroom renovations · Design-build Markham
Visit website Call 416-896-7676
5.0 from 66 Google reviews

P&O General Construction

Best for on-site project management

GTA construction company doing additions, full-home renovations, stairs, wall removal, kitchens and bathrooms for homes and commercial clients.

Updated

Why it ranks here

  • Project managers stay on site through each job and keep the client and trades in contact.
  • Runs jobs in three stages, Align, Plan and Execute, settling scope, timelines and contract terms before work starts.
  • During planning it orders materials and lines up engineers, designers, inspectors and subcontractors as needed.
  • Project gallery includes additions, separate entrances with walkout basements, and basement finishing.
  • Takes on stair renovations, wall removal, decks and fences, and commercial work as well as homes.
Home additions · Full house renovations · Stairs renovations · Wall removal · Kitchen renovations Markham
Visit website Call 647-773-0105
4.9 from 101 Google reviews

YiXin Construction

Best for additions planned in VR

Markham design-build contractor doing additions, custom home rebuilds, basements, kitchens and commercial fit-outs, with VR design walkthroughs.

Updated

Why it ranks here

  • Has 16 years of local experience as a Markham-based general contractor.
  • Clients walk through their redesigned space in VR goggles before construction starts.
  • Its founder and principal architect, Niko Chen, is also an engineer.
  • Rebuilds aging houses as new custom homes and adds structural extensions, including in North York and Scarborough.
  • Its engineers inspect and measure each site and draw up detailed floor plans.
  • Roofing and hardscaping jobs finish with a drone inspection.
Home additions · Custom home rebuilds · Basement suites · Commercial renovations · Kitchen renovations Markham
Visit website Call 905-604-2595
4.9 from 60 Google reviews

Home Additions Toronto

Remodelling company in the Toronto area taking on home additions and general remodelling work.

Updated

Why it ranks here

  • Rated 5.0 from 26 Google reviews, level with the top rating on this list
  • Based in Woodbridge, outside Markham
  • Its services include home additions and home remodelling
Home additions · Home remodelling Based in Woodbridge
Visit website Call 437-451-0054
5.0 from 26 Google reviews

Master Edge Homes

Family-owned Markham design-build renovator doing kitchens, bathrooms, main floors, additions and accessible conversions in Markham, King City and Newmarket.

Updated
  • Founded in 2005 by carpenter Dwayne Butler and run as a family business with his wife, Anne.
  • Before founding it, Dwayne spent years framing and supervising sites in production housing.
  • Holds Adaptiv Living certification and Net Zero training across its team.
  • One project turned a single-car garage into an accessible suite with a bedroom, living area, kitchenette and access ramp.
  • Commits to a fixed sum once a detailed scope of work is set.
  • Clients follow progress, schedules and selections through its client care software.
Home additions · Kitchen renovations · Main floor renovations · Accessible bathrooms · Design-build Markham
Visit website Call 905-201-1054
4.8 from 24 Google reviews

Peacehaven Construction

Canadian-owned GTA renovation and construction company doing additions, basements, kitchens, bathrooms, full renovations and exterior work such as roofing and siding.

Updated
  • Has 15-plus years of building work behind it, by its own count.
  • Builds rear extensions, garage conversions and second-storey additions.
  • Basement builds include income suites, home theatres, gyms and rec rooms, with waterproofing and insulation.
  • Clients deal with a single contact from concept to handover and get weekly progress updates and written scopes.
  • Beyond home work, it offers technical management and layout on infrastructure, mid-rise and high-rise jobs.
Home additions · Basement finishing · Kitchen renovations · Full home renovations · Exterior and siding Markham
Visit website Call 416-843-8581
4.9 from 17 Google reviews

Ranks 07 to 10

Monlis Homes

Custom home builder

4.6 905-209-1990CallWebsite

Northvale Renovation

Home builder

5.0 647-991-9222CallWebsite

Esquire Homes

Home builder

4.3 905-415-1880CallWebsite

Greywood Homes

Custom home builder

5.0 416-830-3300CallWebsite

Compare the firms

FirmBest forServicesGoogle ratingArea
01Canadian Constructor CreationsFull-home renovations that need plans drawnHome additions · Full home renovations · Basement conversions · Bathroom renovations · Design-build5.0Markham
02P&O General ConstructionOn-site project managementHome additions · Full house renovations · Stairs renovations · Wall removal · Kitchen renovations4.9Markham
03YiXin ConstructionAdditions planned in VRHome additions · Custom home rebuilds · Basement suites · Commercial renovations · Kitchen renovations4.9Markham
05Master Edge HomesAccessible and barrier-free home renovationsHome additions · Kitchen renovations · Main floor renovations · Accessible bathrooms · Design-build4.8Markham
06Peacehaven ConstructionSecond-storey additions and basement income suitesHome additions · Basement finishing · Kitchen renovations · Full home renovations · Exterior and siding4.9Markham

What to check before hiring a home addition contractor in Markham

Five things to confirm with any firm, on this list or not, before you sign. The rules below are Ontario's and Markham's.

  1. Registration with the WSIB

    Ask the firm for a clearance certificate from the WSIB, which confirms it is registered for workers' compensation and its account is in good standing. The certificate confirms the firm is registered with the WSIB and up to date on its premiums, so check its dates cover your job.

  2. Liability insurance

    Ask for a certificate of insurance that names the firm and shows commercial general liability coverage in force for the dates of your job, and check that the subcontractors it brings in are covered too.

  3. The building permit from Markham

    Building permits for homes in Markham come from the City of Markham, and every addition needs one, and often a zoning review first. Agree in writing who applies for the permit and books the inspections.

  4. A written contract

    Get the scope of work, the payment schedule tied to stages of the work, start and finish dates, how changes are agreed and priced, and who handles permits and cleanup, all in one signed contract before any work starts.

  5. The warranty

    A renovation is not a new home, so the new home warranty rules usually do not apply: get the firm's own workmanship warranty in writing, with what it covers and for how long. Renovators in RenoMark, the Canadian Home Builders' Association program, offer a minimum two-year warranty on their work.

Types of home addition contractor in Markham

The 10 firms on this list fall into 4 groups, read from what each firm's own site says it does and how it is listed on Google.

Home builders4

Home builders build new houses as their main work, and some take on additions and major renovations too.

Design-build firms3

Design-build firms design the project and build it under one contract, so one firm answers for the drawings and the work.

Renovation companies2

Renovation companies renovate existing homes, one room at a time or all of it at once.

General contractors1

General contractors run building projects of many kinds and bring in the trades each job needs.

Home additions in Markham: common questions

Do I need a permit for a home addition?

Yes. An addition changes the footprint or height of the house, so it needs a building permit and often a zoning review for setbacks and lot coverage. Plans are usually drawn by a designer or architect before the permit application goes in.

Can I add a second storey to my house?

Often, but the existing foundation and walls have to carry the new load. An engineer checks the structure before design starts, and the contractor builds to those drawings.

What happens before an addition is built?

A survey of the lot, a check of the zoning rules for setbacks, height and lot coverage, drawings by a designer or architect, an engineer's review where the structure is affected, and the building permit. Ask the firm which of these steps it handles and which it expects from your designer.

Can I live in my house while an addition is built?

Often. Most of the work happens outside the existing walls until the new space is joined to the house. Expect noise and dust, and a few days without power or water when the addition is tied in.

How do I check that a contractor in Markham is registered with WSIB?

Ask the firm for a clearance certificate from the WSIB. The certificate confirms the firm is registered with the WSIB and up to date on its premiums, so check its dates cover your job.

Who issues building permits in Markham?

Building permits for homes in Markham come from the City of Markham. For home addition work, every addition needs one, and often a zoning review first. Many firms apply for the permit as part of the job, so agree who does it before you sign.

Before you get quotes

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