Who We Are

Since 2005, O.N. Site Construction Inc., has provided general contracting and professional project management services to an enviable client list that includes some of Canada’s top companies. We are a service-oriented company, with an earned reputation for quality workmanship and unprecedented customer service. We provide national coverage with active construction projects in the commercial sector across the GTA, Northern Ontario, Manitoba, BC and Alberta.  Projects range from small interior renovations to complex multi-million-dollar projects.

We strive to exceed client expectations in a professional, timely and cost-effective manner leveraging three strategic pillars: service, safety, and sustainability. Our core belief is that the true value of a construction management relationship can best be harnessed by viewing ourselves and acting as, an extension of our client and all stakeholders involved in project delivery. At O.N. Site Construction Inc., we are committed to providing reliable, quality workmanship that exceeds our clients’ expectations.

Role Description

This is a full-time on-site and in the office Construction Estimator role at O.N. Site Construction Inc. The Construction Estimator will be responsible for estimating construction costs, performing quantity take-offs, managing project budgets, and communicating with clients and subcontractors. The Construction Estimator will work closely with project managers and stakeholders to ensure that projects are completed on time and within budget.

We are seeking an experienced, highly motivated Construction Estimator that comes with multi project experience who will work closely with a team of highly qualified professionals on medium size, multi-trade, commercial industrial renovation, or interior fit-out projects ranging from $200K to $15 million.


  • Analyze project plans, specifications, and other relevant documents to determine project requirements and scope of work
  • Prepare and submit accurate and timely cost estimates, bids, and proposals for construction projects
  • Estimate costs for labour, materials, equipment, and subcontractors, considering factors such as project size, complexity, location, and duration
  • Collaborate with architects, engineers, project managers, and subcontractors to clarify project details and ensure accurate cost estimation
  • Research and source pricing information for materials and equipment from suppliers and subcontractors
  • Review and analyze subcontractor bids and negotiate pricing to obtain competitive and cost-effective solutions
  • Provide clear and detailed breakdowns and maintain accurate records of cost estimates, including labour hours, quantities, unit costs, and overhead expenses
  • Monitor and track project costs, identifying any variations or discrepancies and making necessary adjustments


  • Bachelor’s degree in construction management, engineering, or a related field (or equivalent work experience).
  • 2-4 years of proven experience as a Construction Estimator or similar role in the construction industry
  • Construction Estimating and Quantity Take-offs skills.
  • Cost Management and Budgeting skills
  • Excellent written and verbal communication skills
  • Experience working with clients and subcontractors
  • Attention to detail and a high degree of accuracy in cost estimation
  • Ability to read and interpret construction plans, specifications, and contracts
  • Proficiency in construction estimating software
  • Ability to work independently and as part of a team, managing multiple projects simultaneously
  • Are highly motivated and hardworking
  • Detail oriented

Working Conditions

  • On-site and in-office. This is not a hybrid role.
  • Primary work location is 2861 Sherwood Heights, Oakville with potential for work-related travel
  • Exposure to construction work sites, access to your own vehicle is an asset

 What We Offer

  • Opportunity to work with collaborative, experienced and supportive construction professionals serving established brand clients
  • Career growth in a company that values and recognizes the contribution of their employees
  • An energizing work environment that’s committed to achieving quality results reflected in the work we do, demonstrated in the way we treat our customers

O.N. Site Construction Inc. is committed to a process that is inclusive, barrier free and a workforce that reflects the diversity of our community. We encourage applications from all qualified individuals including applicants from all backgrounds.

 If you are interested in the position of Construction Estimator and possess the required qualifications, please submit your resume highlighting your relevant experience and skills to We look forward to reviewing your application!