DEI’s company philosophy is Integrating Proven Technologies Using Sound Engineering Principles. This philosophy guides all our work with the goal of delivering robust, reliable, and resilient design solutions to our clients. Designs are developed from first principles to ensure that technical performance requirements for each project are met or exceeded. In addition to satisfying technical design requirements of each project, DEI prides itself on building long-term relationships with our clients based on trust, experience, and an understanding of their unique and evolving needs. Our personnel include professional engineers licensed to practice in Ontario (P.Eng) and other North American jurisdictions, LEED® accredited professionals and Certified Energy Managers (CEM®). DEI staff are active members in numerous national and international industry associations including the Ontario Society of Professional Engineers (OSPE), American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), Association of Power Producers of Ontario (APPrO), International District Energy Association (IDEA) and the Canadian Green Building Council (CaGBC).

As a firm, DEI has a deep corporate commitment to sustainability, health and safety, and good governance. These principles are supported through regular employee training and professional development activities, information sessions, volunteerism, donating to non-profits and charitable programs, and promoting environmental protection and long-term sustainable solutions in engineering designs. As the focus on sustainable investment grows worldwide, more clients are seeking innovative approaches to reduce greenhouse gas (GHG) emissions to align with internal and provincial targets. DEI continually works with clients to evaluate and implement projects that improve building performance, reduce emissions, increase operational savings, and enhance human health benefits.


Year Established


Years of Experience



Meet Our Team

Aline McMullen

Director of Sustainability


Andrew Millson

Project EIT

Arnar Valmundsson

Senior Project Manager

Charles Aaron

Senior Designer

Curtis Singh

Senior Technologist

Daniel Doherty

Engineering Intern

David Sebastian

Senior Project Manager

George Jones

Senior Project Manager

James Gillis


Jamie Minaret

Sustainability Specialist


Joshua Hall

Project Engineering Assistant

Kayla DiBattista

Manager, Finance and Operations

Martino Beretta


Matthew Doherty

Manager, Marketing and Operations

Meagan Marcyniuk

Project Engineer

Michael Johns

Senior Project Manager

Paul Doherty



Paula Mayor

Project Development Manager

Preet Noor

Manager, Business Development

Vishal Patel

Senior Designer


William Zammit

Supervisor, IT and Quality Assurance


Community Involvement

Environmental Conservation

Doherty Engineering strongly believes in ecofriendly business practices. Many of which include promoting environmental protection in engineering designs, renewable energy options and ideas to reduce carbon footprint.


Paul Doherty conducts mentoring programs for Kids in Ice Hockey. Mentoring and teaching the importance of mental and physical balance, mental and physical agility, coordination, and team spirit. They learn how to strategize and operate as a team, each contributing their own strengths.

Charitable Giving

Doherty Engineering gives back to the community in numerous ways including, donations to employee and client causes, sponsorships of charity golf tournaments, donations to support undergraduate student, and many more.