ENR 2026 Top 20 Under 40
Melanie Jefferies: COO Leads Sustainable, Equitable Development While Improving Profitability and Performance

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ENR 2026 Top 20 Under 40
Melanie Jefferies
35, Chief Operating Officer, Engineering Services
Milhouse Engineering & Construction
Chicago
Jefferies leads enterprise strategy, delivery performance, and operational execution across roughly 60% of a $50-million organization—aligning business development, finance, talent and quality to drive profitable growth. She provides executive oversight and client/partner relationship management for complex, high-visibility projects and new markets. As owner/principal of its new unit Milhouse Development, she also guides community-centered real estate development and investment initiatives.
In the past five years since Jefferies launched the business, she has expanded Milhouse from engineering and construction into a vertically integrated AEC enterprise. Selected by the City of Chicago Dept. of Planning and Development as a co-developer for the “Missing Middle” Housing Initiative, she led a team that is delivering 12 for-sale units across the city’s South Side—helping transform vacant lots in under-invested neighborhoods. This work diversifies revenue, increases enterprise value and advances equitable revitalization
She is an active civic leader who invests her time in strengthening Chicago’s AEC and real estate sectors—serving on the boards of City Year Chicago, Neighborhood Housing Services of Chicago and Milhouse Charities to help build pipelines of diverse engineering talent and provide housing solutions.
What is one challenge that you’ve overcome in your career?
One of the biggest ongoing challenges in my career has been navigating gender and generational expectations as a second-generation leader in a male-saturated industry. I wouldn’t say I’ve completely overcome it, because it remains a constant part of my experience. Earning respect based on results rather than lineage has required steady focus and a commitment to letting my work speak for itself.
That experience has shaped how I lead today. It has made me more intentional about building teams that value different perspectives and about creating opportunities for others who might not see a clear path forward. While the challenge still exists, it has also been one of the most rewarding aspects of my career. It has pushed me to grow, to redefine what leadership can look like, and to help the next generation of diverse talent see themselves represented in this industry.
What has been your favorite or most interesting project you’ve worked on and why?
As Chief Operating Officer, Engineering Services, I’m involved in many projects, often from the very beginning when strategy and collaboration start to take shape. Some of the most interesting have been large, complex efforts, such as Bally’s Casino, where we partnered with eight other firms to deliver as one unified team. Projects like that challenge us to align diverse expertise and priorities, and it’s rewarding to see how collaboration at that scale can create something that defines a city.
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Some of our smaller initiatives have had just as much complexity and meaning. One that stands out is 40 Acres Fresh, a new community-minded grocery store on Chicago’s West Side with a mission to provide healthy food options to residents of neighborhoods with historically limited access to grocery stores. It reminds me that meaningful development isn’t only measured in size or budget, but also in how deeply it serves the people around it. Those projects reinforce why we do this work and how engineering can be a real force for community change.
What’s the best career advice you’ve been given?
The best advice I’ve received is to celebrate the small wins along the way. In this industry, it’s easy to get caught up in meeting deadlines and reaching major milestones so that we can overlook the progress happening in real time. Taking time to pause and celebrate life in the midst of the work, and recognizing those smaller moments of success helps you stay connected to the purpose behind the work. It reminds you that growth and achievement don’t always happen in big leaps, but through consistent effort and teamwork over time.
That mindset has helped me stay motivated and balanced, especially during the most demanding phases of a project. It’s also shaped how I lead, because I try to model that same appreciation within my teams. Recognizing a colleague’s contribution and being an empathetic leader keep morale strong and reinforce that everyone’s effort matters. Over the years, I’ve found that real success stems from those moments of progress that build toward something greater, and from learning to find fulfillment in the process, rather than just the final result.
What’s your career advice for other young professionals in the industry?
The best advice I can give to folks just starting out in the industry is to learn the business side early. It’s important to understand the steps behind a project, not just how it is built. At some point in your career, you’ll transition from focusing on the technical work to leading people and shaping strategy. The earlier you start developing that broader perspective, the better prepared you’ll be for leadership. Take the time to learn how a project makes money, how to read a [profit and loss] statement and how to build strong client and partner relationships. Technical skill will open doors, but understanding the business is what allows you to make a lasting impact. It’s the difference between being a capable contributor and becoming someone who can drive growth and lead an organization forward.
What’s the best part of your job?
The best part of my job is the opportunity to empower communities while continuing my family’s legacy in engineering. Every day brings something new, and that variety keeps the work both exciting and meaningful. I take a lot of pride in what I do, and I view it as a privilege to carry forward the vision my family started and to expand its impact in new ways.



