As the year draws to a close and we look forward to a new one, many have also turned their gaze further into the future. With recent natural events becoming increasingly severe, attention has shifted toward their root cause—climate change—and the urgency for both immediate and long-term solutions. In this global context, the architecture, engineering and construction (AEC) sectors face a pivotal opportunity: retrofitting existing buildings to reduce carbon emissions.

The built environment is a significant contributor to global greenhouse gas emissions, responsible for approximately 37 percent of worldwide emissions. While a substantial portion of this impact stems from the production of materials like cement, steel and aluminum, much attention has historically focused on reducing 'operational' carbon emissions—those associated with heating, cooling and lighting. With operational emissions projected to decrease from 75 to 50 percent of the sector's total emissions in the coming decades—a result from a combination of modernizing existing building stock and implementing energy-efficient practices in new construction—addressing 'embodied' carbon has become increasingly critical. These are the emissions generated during the design, production and use of construction materials. Tackling this challenge underscores the need for collaboration across the building lifecycle, from design and planning to construction and long-term maintenance.

A global assessment of progress reveals a mixed picture, while some countries have managed to reduce building emissions, the overall pace remains inadequate.

Decarbonizing the Existing Built Environment: The Importance of Retrofitting

Achieving the carbon reduction goals outlined in the Paris Climate Agreement requires a shift in how we approach the built environment. A 2023 study highlights the urgency of decarbonizing buildings to keep global warming within 1.5 degrees Celsius. With nearly 80 percent of the buildings that will exist in 2050 already standing today, retrofitting these structures is essential for reducing emissions. Adaptive reuse and retrofits provide a strategic pathway toward achieving net-zero emissions. Yet, the path to retrofitting is not without challenges, including the aging nature of existing building stock and increasingly complex increasingly complex regulatory frameworks. Despite these hurdles, retrofitting offers a powerful means of reducing carbon footprints, making it a critical strategy in meeting international climate commitments, such as those outlined in the Paris Agreement.

A global assessment of progress reveals a mixed picture: while some countries have managed to reduce building emissions, the overall pace remains inadequate. Even leading European nations have hit a plateau, and the United States has recorded a 3 percent increase in building-related greenhouse gas (GHG) emissions from buildings since 2010. This data underscores the need for a more aggressive approach to retrofitting existing buildings and adapting them to meet modern (and even future) energy standards.

The Benefits of Daylight Design

Energy Efficiency and Savings

Natural daylight has always been integral to architecture, offering energy efficiency and occupant satisfaction. Designers have long known that incorporating daylight and views into buildings can enhance both the environment and the operational bottom line. However, proving its direct financial benefits has historically been a challenge. As a result, the positive impact of daylight on occupants’ well-being, satisfaction and productivity was often seen as anecdotal.

Recent advancements in technology have made daylighting as a dominant interior daytime light source a priority in commercial building design, especially in retrofits. By integrating natural daylight over a significant portion of a building's occupied floor plate, buildings can significantly reduce their reliance on electric lighting, lowering energy consumption and operational carbon emissions. The application of modern fenestration technologies is particularly effective in retrofit projects, where daylighting can cut energy use and costs. In commercial buildings, electric lighting can account for 35 to 50 percent of energy use, often increasing cooling loads due to heat generation. Incorporating strategic, advanced daylighting technologies can reduce cooling energy needs by roughly 15 percent, offering substantial energy savings for a reduced operational carbon footprint while increasing improved comfort and satisfaction for occupants.

Health and Wellness

Daylight's role extends beyond energy savings—research and design standards emphasize its crucial role as a primary interior lighting source, offering significant health and well-being benefits. Daylit environments create natural illumination that not only enhances sensory experiences but also regulates essential biological functions.

Natural light exposure boosts serotonin production, a neurotransmitter that improves mood and mental health. It also helps regulate circadian rhythms—the internal clock that governs sleep-wake cycles—promoting alertness during the day and restful sleep at night. This exposure supports various bodily functions, including digestion, hormone balance and temperature regulation.

Studies support these advantages. Dr. Alan Hedge, a workplace design expert at Cornell University, found that workers in naturally lit offices experienced a 51 percent decrease in eyestrain, a 63 percent reduction in headaches and a 56 percent drop in drowsiness compared to those in offices that did not have daylight, highlighting the link between natural light and healthier, more productive work environments. Additional research from Northwestern Medicine and the University of Illinois indicates that workers with ample daylight experience better-quality sleep, more physical activity and improved overall well-being.

Productivity and Comfort

Natural daylight in workspaces can directly affect a business’s bottom line too. Given the choice, most people prefer to work in a naturally daylit space rather than one illuminated by fluorescent or LED light sources. Natural daylight has the unique ability to create a sense of comfort, reducing stress and enhancing mental focus. Spaces infused with daylight are known to inspire creativity, elevate mood and create a more comfortable atmosphere for occupants. 

In a 2021 Future Workplace study conducted for the Harvard Business Review, "access to natural light and views of the outdoors" emerged as the most desired workplace feature. The study revealed that 70 percent of participants felt that natural daylight directly improved their work performance, highlighting its role in fostering a more productive environment.

The comfort provided by daylight also enhances employee well-being. The same Future Workplace study found that over one-third of 1,614 employees surveyed felt they lacked sufficient daylight in their workspaces, with 47 percent reporting fatigue and 43 percent feeling gloomy without a window. Conversely, 78 percent of respondents said that daylight illumination improved their well-being, highlighting the power of strategic daylighting design to reduce stress and enhance focus, making it a key element in creating effective work environments.

Case Study: The Sawtooth Building - A Testament to Innovation and Preservation

Retrofit projects offer great potential but come with challenges due to the constraints of existing structures. Architects and designers must balance structural integrity, outdated systems and regulatory requirements while preserving a building's historical character. This process requires innovative problem-solving to integrate modern amenities, such as energy-efficient lighting and insulation, without compromising the original design. The transformation of a 1919 spark plug factory in Sioux Falls, South Dakota, into the new headquarters for Click Rain and Lemonly exemplifies how retrofits and adaptive reuse can merge historic preservation with modern functionality.

As advocates of flexible work, both Lemonly and Click Rain sought to create a "home base" for their teams. The new headquarters needed to support frequent video calls and virtual collaboration while being a place where employees enjoy spending time in person. To achieve this, the design team incorporated translucent panel skylights with fiberglass-reinforced polymer (FRP) face sheets from our team at Kingspan Light + Air. These skylights offer high thermal performance while controlling problematic solar heat gain, allowing soft, controlled natural daylight to fill the interior and reducing the daytime need for electric lighting. This design choice also helped maintain the building's energy efficiency by preventing heat gain in the summer and heat loss in the winter.

Daylighting played a crucial role in the project, driving energy savings and creating a bright, welcoming atmosphere that enhances productivity and well-being. The renovation skillfully balanced the building's industrial heritage with modern needs, featuring open-concept workspaces, private offices and meeting areas. Glass partitions allowed daylight to flow throughout, creating a comfortable and visually appealing environment—demonstrating how sustainable design can honor a building's history while meeting contemporary needs.

A Call to Action for Architects and Design Professionals

As architects and design professionals, the imperative to leverage adaptive reuse and retrofitting has never been more evident. The urgency of climate change and the need for sustainable solutions have placed the AEC sectors at a crossroads. Retrofitting existing buildings and integrating energy-efficient solutions, like daylighting, align the built environment with the targets set by the Paris Agreement. While the path forward involves challenges—such as aging infrastructure, regulatory hurdles and the need to preserve historical character—the potential rewards make this effort essential.

The buildings and construction sector has a responsibility—and a unique opportunity—to lead the way in shaping a sustainable future. By modernizing existing structures, we can honor their history while creating healthier, more productive and efficient spaces. By embracing the challenges and possibilities of retrofitting, the buildings and construction sector can create a legacy of lasting change.