Breaking the Cost Barrier: Debunking the myth that sustainable design costs more

“Sustainable design is too expensive.” It’s an all-too-common refrain. It’s also a myth.

We’ve known for years that sustainability doesn’t have to cost more.

In the early 2000s, when LEED was still new to the market, studies showed that the average surcharge for LEED-certified buildings was only 2 percent, but additional investment typically yielded operational savings worth ten times that much. For the last ten years, research has consistently shown that there are no additional costs associated with designing to LEED standards. In 2015, the Pennsylvania Housing Finance Agency became the first public agency to add Passive House into its incentives. In the first two years of available incentive funding, Passive House projects had a slight cost premium compared to conventional construction. By the third year, however, they came in cheaper per square foot than conventional construction as the market matured and builders became more familiar with the process.

We should remember, however, that sustainability and sustainable design isn’t new. The broad range of design and construction techniques throughout the world and the many centuries-old buildings that still stand—and are standing the test of time—are full of wisdom and lessons learned. It’s ironic that modern third-party certifications such as LEED, Passive House, or Net Zero Energy, which were created to achieve similar goals around longevity and sustainability, are still regularly dismissed as too expensive.

Pursuing these sustainable design certifications provide excellent frameworks and a defined path, but sustainable design is not just a check list of tasks; it is a philosophy and approach that can—and should—be present in all our infrastructure from now on. Although we integrate sustainable design into all our work at Perkins Eastman, our K-12 educational environments have truly been pushing the limits over the past two decades, because we believe that schools can become the catalysts for large-scale decarbonization within their cities and communities. From this work driving decarbonization forward, we’ve learned how to do it cost-effectively, because sustainability can’t just be about doing the right thing, it also must make financial sense.

Take the Boston Arts Academy, for example. Originally required to pursue LEED certification, it became clear through the visioning sessions held for staff and students that the school had bigger sustainability aspirations. They wanted to create an environment that was not only good for the planet, but which also prioritized human health and well-being.

The Boston Arts Academy paid more than a half-million dollars more for triple-paned glazing, but the cost more than paid for itself in the form of less money spent on heating and cooling systems.
Boston Arts Academy photographs © Robert Benson Photography

As the design evolved, our team explored triple-pane glazing instead of the standard double-pane to maximize interior thermal comfort and improve energy performance. The added cost, however, was estimated at $515,550 more than the double-paned glazing—a not-insignificant upgrade. But the improved envelope performance allowed the team to reduce the number of air-source heat pumps it specified and eliminate the entire perimeter radiant heating system. This approach resulted in $800,000 in first-cost savings. In the end, therefore, the added cost for the building envelope paid for itself—and then some—in the form of much less money spent on the mechanical systems. Even better, we delivered a higher-performing building with reduced energy consumption and better thermal comfort than if we had followed a more traditional route. And the savings only compound; we’re not even accounting for annual operational cost reductions that are associated with a higher-performing building.

Triple-paned glazing at Boston Arts Academy allows plenty of daylight while also providing thermal comfort against the temperatures outside.

At John Lewis Elementary School in Washington, DC, we were hired to deliver the District of Columbia Public Schools’ (DCPS) first Net Zero Energy school—on a LEED Gold budget, DCPS’ baseline sustainability requirement. The project was budgeted during the capital planning process years before the NZE goals were established, but rather than request additional funding, the team took advantage of “free resources,” such as the sun’s positioning throughout the course of the year, to minimize the amount of energy needed to heat, cool, and light the building. Smart building orientation, window-to-wall ratios, daylighting, and shading strategies all played a role in realizing a higher-performing project with no added cost.

John Lewis Elementary School has earned a rare double-Platinum certification for both LEED and WELL, meaning it’s among the highest-performing schools for both energy efficiency and its robust contribution to the health and well-being of those who occupy it.

The team also evaluated HVAC systems, comparing DCPS’ standard system (an air-cooled Variable Refrigerant Flow, or VRF) with a geothermal system. The geothermal option had a $660,000 first-cost premium over the standard VRF, but delivered $90,000 in annual energy savings, resulting in a payback of around seven years. Even though there was an increase in first cost for the geothermal, the passive-design strategies the team pursued to optimize the design along the way allowed the project to absorb the added cost of the geothermal and not go over budget. It is important to note that DCPS chose to pursue a power purchase agreement (PPA) for this project instead of procuring the solar panels outright, which eliminated the costs of the solar panels from the equation.

John Lewis Elementary is packed with opportunities for learning beyond the confines of its classrooms.

Delivering this project within budget demonstrated that pursuing NZE (or NZ Ready without the solar costs included) doesn’t inherently increase costs, and that the annual operational cost savings can be significant. Compared to the previous elementary school in place before the John Lewis modernization, the new structure saves the district close to $300,000 annually in energy costs—money that can be better spent on education instead of operation.

A broader cost study with Fairfax County Public Schools (FCPS) in Virginia provided more insight. FCPS engaged Perkins Eastman and CMTA engineers to study what it would take to design and build Net Zero Energy and Net Zero-ready schools versus their standard bond-funded designs, which call for more traditional heating/cooling methods. The study focused on elementary-school renovations and additions as well as new construction, considering a life-cycle cost evaluation to weigh operational and maintenance cost savings against initial construction outlays. FCPS currently uses an older version of the Collaborative for High Performance Schools (CHPS) standard, which does not have the same rigor as LEED Gold, so there was going to be a bigger budget gap between the district’s base-design model and Net Zero Energy.  Our study did find an increase in first costs for Net Zero Ready work in the range of 5-10 percent for new construction and major renovation projects respectively. It showed that, depending on your starting point, there may be some added first costs, but they can be minimized through careful optimization, leveraging passive design in tandem with other energy-conservation measures.

When sustainability is integrated from the outset, Net-Zero Energy (NZE), high-performance design, and other sustainable goals can be achieved without breaking the budget. But because there are real added costs associated with high-performance systems such as geothermal and photovoltaics (which could rise even higher in the current economic climate with pinballing tariffs), optimizing our designs to passively take advantage of free resources is the safest, most cost-effective investment we can make.

If your team decides that photovoltaics and geothermal is the way to go, however, there are ways to reduce your expense. Power Purchase Agreements—when a third party installs and maintains the solar panels and the building owner buys back the renewable energy—eliminates your initial capital outlay. For geothermal technology, there’s been an increase in many local, state, and federal incentives that would make it cost-neutral or cost-negative in comparison to standard HVAC.

But perhaps the most important cost conversation is the one we rarely have: the cost of not designing sustainably. Because sustainability isn’t just about energy; it’s about value—economic, environmental, and social. If a project isn’t delivering on all three, is it really sustainable? Can it even be considered good design? One of our dearest-held values that guides our work at Perkins Eastman is that good design is sustainable design. An important milestone in this journey was Dunbar Senior High School in Washington, DC. When it opened in 2013, it became the highest-scoring LEED for Schools project in the world.

The heart of the school at Dunbar Senior High School is awash in natural light, thanks to strategic glazing and an expansive skylight.

Critics at the time questioned whether DCPS could afford to build schools at that level. But the results were undeniable: test scores rose, enrollment climbed, and graduation rates improved. This is the long-term value of sustainability. Not only is it within reach—it can be transformational. That is the value of good, sustainable design.