IWBI Signature Interview Series: Shaping Buildings, Shaping Lives—A Conversation on Leading Innovation in Healthy, Sustainable Buildings

As a quiet force in sustainable building, Deb Cloutier, CRE® has shaped the industry in ways few recognize. While her fingerprints are everywhere – from groundbreaking government initiatives to transformative corporate projects – she has often been the unseen catalyst, preferring to let her work speak for itself. For over three decades, Deb’s impact has rippled through public and private sectors, sparking innovation in sustainable building practices.

Today, as Chief Sustainability Officer of the Blackstone Portfolio Company Legence, Deb oversees sustainability initiatives across a $2 billion enterprise employing over 5,700 people. Under the Legence umbrella, companies like CMTA, A.O. Reed, Black Bear Energy, Therma, and SC Engineers have achieved remarkable milestones: designing more than 10 million square feet of net zero buildings, managing $21 billion+ of energy efficiency and renewable energy projects, and securing more than 1,000 certifications in global leadership building programs, including LEED and the WELL Building Standard.

Her journey includes founding RE Tech Advisors, now a Legence company, which has become a cornerstone in sustainable real estate consulting. Under her guidance, RE Tech has established a remarkable track record of designing and implementing award-winning programs to help clients decarbonize and improve sustainability performance. RE Tech partners with many of the largest institutional owners and investors of commercial real estate, as well as federal agencies and industry associations such as the U.S. Department of Energy, U.S. Environmental Protection Agency, GRESB, BOMA International, and the Institute of Real Estate Management.

Deb’s career embodies Legence’s mission: reducing energy costs and meeting decarbonization goals while improving building health and wellness. We recently sat down with her to explore how she’s helping reshape our built environment for a more sustainable future.

Q: For those of us who have been in the building industry long enough, we’ve had a chance to hear the famous Winston Churchill line many times: “We shape our buildings, thereafter they shape us.” What inspired you to dedicate your career to improving and advancing better buildings? And when did it become clear this was the field you wanted to dedicate yourself to?
I was fortunate to be an early pioneer, driving positive changes in the built environment. Working on the Clinton administration’s White House greening initiative in the early '90s changed everything for me. Back then, I was helping create the first real guide to help architects understand the environmental impact of their material choices - something that seems obvious now but was revolutionary at the time. I got to work with these incredible pioneers who went on to start the US Green Building Council. Being around people who saw buildings not just as structures, but as opportunities to reshape our relationship with the environment - that’s what hooked me. I knew I’d found my path.

As my early career progressed, I committed my energy and talents to driving innovative projects, such as launching the ENERGY STAR® Buildings Program and the Department of Energy Better Buildings Initiative. The statistic that really lit a fire under me was learning that 40% of total global emissions are from the built environment. That’s when it clicked: we could tackle climate change and boost bottom lines at the same time. At the age of 28, I founded my first business with a specific focus on improving the carbon footprint of buildings while simultaneously improving the financial performance of portfolios.

Along the way, I was fortunate to lead the development of several transformative projects, including the creation of the Green Lease Leaders recognition program, the NAREIT Leaders in the Light awards program, and the BOMA Energy Efficiency Program (BEEP) curriculum, which has reached more than 50,000 practitioners. Fannie Mae used our research to launch the highly successful Green Rewards program that enhances multifamily property loans by underwriting future projected costs and savings from energy and water improvements, resulting in 5% higher loan proceeds and interest rate reductions. Additionally, our team led the data collection effort with Fannie Mae and the EPA which resulted in the development of a 1-100 ENERGY STAR score for multifamily buildings. We also authored key studies and guides, including “Energy Efficiency in Separate Tenant Spaces – A Feasibility Study” for the Department of Energy and “A Practical Guide to Green Real Estate Management” for the Institute of Real Estate. From 2006 to 2009, we led the development and coordination of an Annual EPA Partnership Program Workshop, uniting national experts on public-private partnership programs to tackle environmental issues that influence business practices.

For more than 20 years, my team has relentlessly focused on catalyzing the adoption of strategic energy management and decarbonization of buildings. By the time I worked with Blackstone to create Legence, RE Tech Advisors was advising and helping portfolio owners of more than $1.5 trillion of assets under management, representing over 5 billion square feet and 23,000+ properties. Having an impact at that scale continues to drive my enthusiasm every day.

Q: You’ve spent your career helping major businesses and organizations enhance and improve the health and sustainability of their buildings. Now, as Chief Sustainability Officer at Legence, how are you applying that experience and background to guide your own company? Looking ahead over the next five years, what would you consider as success?
My role at Legence has given me a unique platform to drive industry change. We call ourselves an Energy Transition Accelerator® because that’s exactly what we do - help over 17,000 clients transform their buildings, from data centers to hospitals to schools. What excites me is the scale of our potential impact. Consider this: 80% of 2050’s buildings already exist today. So, while new construction matters, the real game-changer is retrofitting existing buildings.

Looking ahead five years, I measure success through two lenses. First, we need to move faster. Much faster. With 2023 being the hottest year in 125,000 years, and billion-dollar weather disasters now hitting every 18 days, we’re out of time to debate. Cutting building emissions is one of the biggest, most achievable ways to make an immediate difference.

Second, and this is crucial - this transition to a low-carbon economy isn’t just about avoiding disaster. It’s about seizing opportunities. The organizations that get ahead of this curve, that embrace innovation and prioritize both environmental and human health in their buildings, they’re the ones who’ll thrive. They’ll see it in their bottom line, their people, and their environmental impact.

At Legence, we keep it simple. Every solution we recommend must decrease operating costs, cut carbon emissions, and improve people’s well-being. Because ultimately, this isn’t just about better buildings - it’s about building a better future.

Q: In the U.S. and globally, governments as well as institutional and real estate investors are increasingly demanding more of our buildings. How do you see the landscape evolving in terms of social sustainability – which, as described by the UN Global Compact, “is about identifying and managing business impacts, both positive and negative, on people” – particularly regarding disclosure, compliance, and the future role of healthy buildings?
The landscape of building performance is shifting dramatically right now. Here’s what we’re seeing at Legence, especially with our data center and healthcare facility clients - they’re grappling with complex disclosure requirements while trying to improve their buildings’ performance. And there’s a simple truth driving this: we spend most of our lives inside buildings. Whether we’re working, healing, learning, or just living, these spaces shape our daily experiences.

The data is crystal clear - employee well-being and productivity are directly linked to how well a building performs. When we talk about social sustainability, we’re really talking about improving people’s lives through better buildings. In today’s market, designing for occupant health isn’t just nice to have - it’s a business imperative.

But here’s the key: you need data to make smart decisions. Understanding exactly how your building affects human health helps owners make investments that benefit the environment, the occupants, and financial returns. Whether we’re looking at air quality, water systems, movement opportunities, or occupant controls, you need that baseline performance data to drive better health and performance outcomes.

Remember, people are your biggest expense in any building. Even small improvements in health and productivity can have major financial returns. And here’s the good news - you don’t have to choose between healthy buildings and energy efficiency. The secret is in the follow-through: measure your results (through air quality testing or occupant surveys) and communicate what you’re doing. That’s where frameworks like WELL certification really shine - they help you do both.

Q: When it comes to the shared mission of driving market transformation in the built environment, what’s the one practice you wish all buildings were implementing?
If there’s one non-negotiable for buildings today, it’s having a solid decarbonization strategy. It’s not just about being green - buildings without a carbon reduction plan are going to fall behind financially. The market’s already moving in this direction. My advice? Get a plan in place now and stick to it. The longer you wait, the harder and more expensive it gets.