A new study has found that greenhouse gas (GHG) emissions from buildings in the U.S. have increased three percent since 2010 in contrast to emissions from buildings in other G20 nations. The report, Global Retrofit Index Interim Report: Assessing progress on the path to net zero, by 3Keel and Kingspan, examined historical buildings emission trends and retrofitting rates. The report revealed that, over the next 20 years, the U.S. must reduce building emissions by an additional 73 percent to align with the country’s net-zero scenario. It also noted that “without significant interventions, building emissions are expected to continue increasing towards 2050.”
U.S. lagging
With the U.S.’s building stock far off track for reaching net zero by 2050 and without major intervention—as the report notes—the country is unlikely to align with such a trajectory in the coming years. Future gains from energy efficiency are not expected to help as rising demand is expected to result in an increase in building emissions.
Compounding the building emissions problem is the aging of U.S. buildings. According to the report, the average age of U.S. building stock in 2022 was approximately 53 years for commercial buildings and, in 2021, approximately 40 years for residential homes.
Retrofitting is a solution
Retrofitting existing buildings offers significant opportunities for meeting climate targets while also spurring job creation, reducing social inequality, and improving health and quality of living. Even so, there are barriers preventing rapid and widespread implementation. According to the report, some of these barriers include insufficient private investment, an inadequately sized and skilled workforce, and limited awareness amongst citizens and building owners.
“With over a quarter of total global emissions stemming from the operation of our buildings, retrofitting is a pivotal lever for decarbonizing the global economy,” says report author Olwen Smith of 3Keel. “However, this study shows a concerning stagnation of progress. Our analysis of six countries with old building stocks reveals that reductions in building emissions are now stalling and retrofitting rates are lagging far behind what is required to meet net-zero goals.”
The report identified five key elements that are central to overcoming these barriers and delivering a successful retrofitting framework:
- Setting net-zero building performance standards
- Developing a national retrofit plan
- Providing financial incentives and support
- Upskilling the workforce and scaling the supply chain
- Promoting best practices and data transparency
The built environment is responsible for 42 percent of annual global CO2 emissions, according to Architecture 2030.1 That carbon footprint increases with every new build. It is estimated from 2020 to 2060, the world will add about 241,547,904,000 m2 (2.6 trillion sf) of new floor area to the global building stock, the equivalent of adding an entire New York City to the world, every month, for 40 years. Yet the report found more than three-quarters of the buildings that will exist in 2050 have already been built.
These numbers shine a spotlight on retrofitting as one of the keys to reducing the carbon footprint of the U.S. building sector and meeting net-zero carbon targets.
What is retrofitting?
Retrofitting is a process that involves replacing aging or outdated components and systems or adding new features to improve a building’s performance and functionality, making it more energy efficient, comfortable, and sustainable.
There are many different types of retrofit projects, some of which include the following:
- Adaptive reuse adapts buildings to current needs to give them a new use instead of demolishing them.
- Renovation updates an existing building by replacing components such as windows, roofs, or building envelopes to improve the structure’s appearance, functionality, and value.
- Extension adds horizontal or vertical volume to an existing building to expand its functional capacity.
- Restoration aims to prolong the life of a building, preventing its deterioration, damage, or destruction.
Urgent need for retrofitting
Existing buildings comprise the largest segment of the built environment. Many of these buildings are aging and in need of energy-efficient updates. The U.S. Energy Information Administration says 80 percent2 of the 5.9 million3 commercial buildings in the U.S. were built before the year 2000.
It can take between 10 and 80 years for a new energy-efficient building to overcome the negative climate change impacts that were created during the construction process. That points to reusing buildings and retrofitting as a viable pathway to net zero. According to research by JLL, in the global north, retrofitting rates need to triple from barely one percent today to at least three percent of existing buildings per year to meet decarbonization targets.4
The human-made carbon emissions that are fueling climate change demonstrate the urgency of stepping up retrofit projects in the U.S.
A new report from UN Climate Change finds “national climate action plans remain insufficient to limit global temperature rise to 1.5 degrees Celsius and meet the goals of the Paris Agreement.” The report highlighted the latest science from the UN’s Intergovernmental Panel on Climate Change indicates that GHG emissions need to be cut 43 percent by 2030, compared to 2019 levels to limit temperature rise to 1.5 C (34 F) by the end of this century and avoid the worst impacts of climate change.5
The Fifth National Climate Assessment, another recently released report,6 finds the impacts of weather extremes—exacerbated by climate change—are already affecting the American people in far-reaching ways. Precipitation patterns are changing, sea levels are rising, oceans are becoming more acidic, and the frequency and intensity of some extreme weather events are increasing.
According to this report, the U.S. average temperature has increased by -17 to -16 C (1.3 to 1.9 F) since 1895, and most of this increase has occurred since 1970. Temperatures are projected to rise another -16 to -15 C (2 to 4 F) in most areas of the U.S. over the next few decades.
Strategies for retrofitting
There are several ways to retrofit, including the following:
Integrating renewable energy systems
Integrating these renewable systems—such as solar panels, wind turbines, or geothermal systems—can generate clean energy and reduce reliance on fossil fuels that contribute to GHG emissions. The best option here is for direct renewable systems on the building or site, then investing or being an off-taker in projects in the utility grid. The last option is virtual power purchase agreements (VPPAs) or projects outside of the grid.
Making sustainable material selections
Using environmentally friendly materials with low embodied carbon and recycled content reduces the environmental impact of construction and contributes to a circular economy. Using databases such as the Embodied Carbon in Construction Calculator (EC3) or mindful materials to search and verify these products has made the process significantly easier over the past few years.
Using smart lighting systems and technologies
Smart technologies such as automated thermostats and occupancy sensors can help monitor and control energy consumption, optimizing energy use by adjusting heating, cooling, and lighting based on occupancy. Energy-efficient and longer lasting LED lights are another easy way to reduce energy consumption in retrofitted buildings.
Updating heating and cooling systems
Replacing old furnaces and air conditioning systems with updated HVAC systems can improve building energy performance and enhance occupant comfort. Moving away from combustion heat sources and focusing on electrification is critical in retrofit projects.
Improving water efficiency and conservation
Water efficiency can be improved by replacing old plumbing fixtures with more efficient fixtures such as low-flow showerheads and toilets. Additionally, rainwater harvesting and wastewater recycling are strategies that can be used to minimize water usage.
Upgrading the building envelope
Retrofitting building envelopes with insulated metal panels (IMPs) reduces heat transfer and energy loss. IMPs, which can have thermal resistance ratings upwards of more than R-8 per 25 mm (1 in.), reduce a building’s carbon emissions while increasing energy efficiency, building durability, and air tightness. The challenge here is to maximize efficiency without making regrettable substitutions for materials high in global warming potential (GWP). Sourcing the best products with Environmental Product Declarations (EPDs) to validate the impacts must not be overlooked.
Impact of retrofitting
One of the biggest impacts of retrofit projects is the avoidance of much of the embodied carbon emissions that are generated by the construction of new buildings. Data from the Institute for Market Transformation revealed that retrofitting buildings can save 50 to 75 percent of a building’s embodied carbon (the carbon emissions released during the lifecycle of building materials).7
Retrofit projects also have a positive economic impact by stimulating job growth. According to McKinsey data, job gains from retrofit projects could stimulate local economies by adding four million to six million jobs per year.8
Giving old buildings a new lease on life transforms and revitalizes communities and improves the quality of life.
Benefits of retrofitting
Building retrofits offer a wide range of long-term environmental, operational, and financial benefits, including the following:
Reduced environmental impact
Retrofit projects that reduce energy consumption positively impact the environment by reducing carbon emissions. Integrating eco-friendly materials, energy-efficient lighting, thermally efficient building envelopes, renewable energy, and other sustainable strategies all work to minimize the environmental impact of buildings and help combat climate change.
Improved indoor air quality
Sustainable retrofits that use non-toxic building materials and include upgrades to ventilation systems can improve indoor air quality. Environments created with enhanced ventilation and thermal comfort, and free from harmful chemicals found in some construction materials can improve the overall health and productivity of building occupants.
Increased energy efficiency and operational cost savings
Replacing poor insulation, outdated HVAC systems, and leaky building envelopes not only increases energy efficiency, but can also reduce maintenance costs. The average reduction in operating costs in the first 12 months for green renovations and retrofits of existing buildings is 11.5 percent, and more than five years, these buildings yield a cost savings of 17 percent, according to a market report by Dodge Construction Network.9
Increased market value
Retrofit projects that prioritize sustainable building practices are more attractive to potential buyers and tenants and command higher rental and resale value. According to JLL, evidence now shows green certifications like LEED and BREEAM result in a rent premium of six percent and a sales premium of 7.6 percent.10
Extended building lifespan
Building retrofits can also increase the lifespan of existing buildings. Updating HVAC systems, electrical systems, and windows; improving insulation; and addressing structural issues can extend the useful lifespan of buildings.
Successful retrofits
There are many examples of successful retrofit projects that demonstrate the positive impact and benefits of updating buildings instead of razing them. One recent example was the renovation of the mixed-use building at 808 Memorial Drive located in Cambridge, Mass.
This building, consisting of residential and commercial units, needed a renovation that met high standards of energy efficiency and sustainability. To meet these standards, architects selected IMPs with high thermal performance.
The panels offer excellent insulation properties, which help to reduce the amount of energy needed to heat and cool the building. This, in turn, helps to reduce the building’s carbon footprint and operating costs. Additionally, the panels are designed to be airtight, which helps minimize air leakage and further improve energy efficiency.
Sustainable in design, the IMPs used in this project contain a high percentage of recycled content. Additionally, the panels are manufactured using a low-energy process, which further reduces their environmental impact.
Conclusion
The U.S. could see a massive shift to retrofit projects due to increasing interest rates, the rising cost of building materials, and limited availability of land for new buildings. That is good news for the environment.
Retrofit projects are a powerful lever for reducing the carbon footprint of the built environment. Through renewable energy systems, sustainable material selection, smart technologies, updated HVAC systems, improved water efficiency and conservation, and upgraded building envelope solutions, existing building stock can be transformed into high performance, environmentally friendly structures that contribute to a more sustainable future.
It is clear the pace of retrofitting needs to increase to reach net-zero targets. Retrofitting existing buildings to make them more energy efficient and sustainable is a key part of reducing GHG emissions and accelerating progress on the pathway to net zero.
To download a copy of the Global Retrofit Index Interim Report, go to 3keel.com/published-reports.
Notes
1 See architecture2030.org/why-the-built-environment/
2 See eia.gov/consumption/commercial/data/2012/bc/cfm/b8.php
3 See eia.gov/consumption/commercial/
5 Go to https://unfccc.int/news/ and search “New Analysis of National Climate Plans: Insufficient Progress Made, COP28 Must Set Stage for Immediate Action”
6 See https://nca2014.globalchange.gov/report
7 Go to imt.org/news and search “Should I Stay or Should I Go: The Embodied Carbon of Buildings”
9 See corporate.carrier.com/Images/Corporate-World-Green-Building-Trends-2021-1121_tcm558-149468.pdf
As sustainability director for Kingspan North America, Brent Trenga is committed to reducing the environmental impact of business operations, products, and services through continuous improvement and environmental transparency. Since 2015, Trenga has led Kingspan North America’s material health and transparency program while driving a culture of healthier building, healthier planet, healthier people across Kingspan’s global footprint. He also leads the company’s global Planet Passionate 2030 program looking after the Americas, supports strategic planning for the business development group, and provides insight on current and future sustainability initiatives.
