About Harborline Sterling Construction
A principal-led general contractor based in Toronto, building homes, businesses and public spaces across Ontario with one accountable team, from permits to keys.
Built around accountability
Harborline Sterling Construction Inc. was founded by Mansoor Alam Khan and Maqsood Mohammed to give homeowners, businesses and public owners something that is surprisingly hard to find in construction: a builder who answers the phone, is straight about cost and schedule, and finishes what it starts.
We work in three divisions. Commercial construction, from ground-up buildings to tenant build-outs, design-build and construction management. Residential renovation, from basements, kitchens and bathrooms to additions, driveways and outdoor living. And infrastructure and public works, from roads and sidewalks to street lighting, parks and underground services.
Our clients include homeowners, franchise owners, medical and professional practices, restaurant operators, property managers, developers and public agencies. Every one of them gets the same thing: one contract, one point of contact, and a team that is responsible for the result.

Meet our co-founders
Harborline Sterling is principal-led. Our co-founders personally oversee the projects we take on, so clients get senior judgment, fast decisions and direct accountability.
Mansoor Alam Khan
Co-Founder and PrincipalMaqsood Mohammed
Co-Founder and PrincipalHow we deliver your project
We plan, manage and take responsibility for the whole project. Specialist work is carried out by licensed, insured trade partners that we select, coordinate and supervise, so you deal with one team and one point of contact from start to finish.
Three commitments on every project
Single point of responsibility
One contract and one accountable team. When something needs answering, you know exactly who to call, and that person can make the decision.
Transparency
Real budgets from real trade pricing, problems raised early, plain-language updates and change orders explained before they are approved.
Responsiveness
Calls and emails returned promptly. Construction has enough variables without a contractor who goes quiet.
What we stand for
Integrity
We tell clients what they need to hear, including when a project is not the right fit for us.
Accountability
We own our commitments on cost, schedule and quality, and we fix what is ours to fix.
Safety
Everyone goes home safe. Safety planning is part of every schedule, not an afterthought.
Craftsmanship
We check the work before it is covered and finish every project properly.
Qualified, insured and accountable
Frequently asked questions
Who leads Harborline Sterling Construction?
Harborline Sterling Construction Inc. was founded by, and is led by, its co-founders and principals, Mansoor Alam Khan and Maqsood Mohammed.
What kinds of projects do you take on?
Commercial construction, residential renovation, and infrastructure and public works, for homeowners, businesses, property managers, developers and public owners.
Who carries out the work on site?
We plan, manage and take responsibility for the project, and specialist work is carried out by licensed, insured trade partners that we select, coordinate and supervise.
Where are you based?
Our head office is in Toronto, Ontario. Our core service area runs from Hamilton and Halton through Peel, Toronto, York and Durham, and north to Innisfil and Barrie. For the right projects, we work anywhere in the province.
Will you provide insurance and WSIB documents?
Yes. Certificates of insurance and WSIB clearance certificates are provided before work starts, as your contract requires.
How do you price projects?
We price your specific project against real trade numbers, so the budget you approve reflects your actual scope rather than a generic estimate.
Let's build together
Put one accountable team in charge: on schedule, on budget, with permits and inspections handled the whole way.
Start your project
Tell us what you are planning. We will set up a straightforward conversation about scope, budget and timeline, with no obligation.