Leveraging Existing and Historic Buildings for Climate Action

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LEVERAGING EXISTING AND HISTORIC BUILDINGS FOR CLIMATE ACTION

by Stevens Krug, AIA, PE, LEED AP, AEE Fellow; Lori Ferriss, AIA, PE, LEED AP BD+C; Channing Swanson, AIA; & Michael Ingui, AIA, NCARB, Certified Passive House Designer

Examples of reuse of historical elements and adaptive reuse can be found throughout history. Using appropriate physical assets created by previous generations is important to reducing greenhouse gas emissions. In this article, the complexities of renovations and reuse will be covered, helpful strategies and opportunities will be identified.

First, we will discuss some truths about climate change. We will describe why the reuse of the existing building stock is one of the most effective tools we have in addressing GHG emissions in the environment.

Next, two case studies will show how architects can address climate change through adaptive reuse and green energy retrofits. First, we will illustrate how an adaptive reuse project can anchor urban revitalization and redevelopment through sustainable design. Then we will describe an approach to address historic masonry Passive House retrofits, which you can apply to all kinds of masonry buildings.

EXISTING BUILDINGS AS AN ASSET IN CLIMATE ACTION

We have created a climate emergency. To have the greatest chance staying below 1.5 degrees Celsius, the ambitious target suggested by the Paris Agreement, emissions must be reduced by 65% by 2030 and to net zero by 2040. Thus, there is a time value to carbon emissions; to reduce the rate of emissions dramatically and quickly, carbon mitigation strategies that yield immediate reductions are more valuable than those that take years. This is where existing buildings enter as a key asset in climate action. Globally, 37% of greenhouse gas emissions come from buildings. Of that, roughly two thirds of emissions come from operation of existing buildings; the rest represent embodied emissions from construction and manufacturing of buildings. In urban centers like New York City, buildings’ contribution is much higher, frequently around 70%. These numbers reveal a tremendous opportunity for climate action in our existing built environment—by reusing and upgrading buildings, we can drive down and decarbonize building operations with minimal upfront, embodied carbon. According to the Zero Net Carbon Collaboration for Existing and Historic Buildings, renovating a building can yield as much as a 75%-80% reduction in embodied carbon compared to replacing it with standard new construction, supporting the need for near-term carbon reductions. Case studies have shown that even if new construction can achieve higher levels of energy efficiency, it can take decades, frequently well beyond 2030 or even 2050, for the higher embodied carbon investment of new construction to pay back through energy savings. Additionally, building reuse, conservation, salvage, and deconstruction offer co-benefits like support of local economic growth, preservation of cultural heritage, and strengthening of community.

Top Left: Exterior of Market One. Top Right: Rooftop solar array and green roof of Market One. Bottom Left: Interior office space of Market One, with original historic elements. Bottom Right: Interior of Market One. Photography: Cameron Campbell

MARKET ONE: ADAPTIVE REUSE AND URBAN REVITALIZATION

There is no more sustainable act than breathing new life into an existing resource. Market One tells the story of how traditionally competing goals—sustainability and historic preservation—can indeed be synergistic. The project illustrates the role historic buildings can play in anchoring urban revitalization with sustainable principles. With pragmatic intent and a sensitive touch, Market One integrates sustainable strategies and rigorous design into a charismatic existing structure, maintaining the building’s original character and yielding healthy, open work environments faithful to its original, airy spaces. The project meets both the challenge of pursuing energy conservation and the Secretary of the Interior’s Standards for Historic Preservation. This project exemplifies the sympathetic integration of new technologies into old structures. The combination of geothermal and solar renewable energy sources allows this project to essentially eliminate energy use from outside sources without dramatically changing the building’s masonry envelope or losing the building’s historic character. Given that central Iowa is 85% powered by wind energy, Market One likely consumes nearly zero fossil fuels. A ground-sourced variable refrigerant flow (VRF) system heats and cools the building. This strategy decouples ventilation requirements from heating and cooling needs, allowing energy to be more efficiently transported by fluid in small-diameter piping instead of by air in large ducts. This aids in maintaining the historic character-defining volumes of the building. A fourstage energy recovery ventilator system (ERV) also serves the building, working in tandem with eighteen geothermal wells just north of the building. Electrical consumption is offset by an array of photovoltaic panels on the roof and in a large solar canopy over the adjacent surface parking lot. LED lighting was provided throughout the building and all water heating is done electrically. Occupancy sensors monitor outlet receptacles, LED lighting, and fixture operation to minimize the buildings energy use. Market One achieved LEED platinum and an Energy Star score of 94.

Left: Front façade of Passive House Plus in Carroll Gardens, Brooklyn. Restoring the front façade and stoop and carefully designing a full-story addition and dormers allowed this house to seamlessly blend with the rest of the neighborhood. Middle: Rear façade of Passive House Plus in Carroll Gardens, Brooklyn. Passive measures and triple-paned glazing from Zola Windows and Doors allowed us to create a light-filled, dramatic rear façade. Photography: John Muggenborg Right Top: Rooftop solar canopy of Passive House Plus in Carroll Gardens, Brooklyn. On the roof, a solar canopy from Brooklyn Solarworks generates electricity while providing shading and preventing solar heat gain. Photography: John Muggenborg Right Bottom: Interior of Passive House Plus in Carroll Gardens, Brooklyn. Minimizing the need for complex mechanical systems allowed us to create open, bright interior spaces. Photography: John Muggenborg

A REPEATABLE APPROACH TO PASSIVE HOUSE MASONRY RETROFITS

As a New York City-based firm, many of our projects include historic masonry retrofits constructed long before modern energy codes were adopted. Preserving historic fabric and mitigating the environmental impact of buildings is as essential to our practice as creating beautiful architecture. Passive House strategies allow us to achieve these goals, while freeing us as designers. Frequently, incomplete information leads to missed opportunities. Many homeowners aren’t aware that through Passive House their home can be quiet, serene, well-sealed, and free of outside allergens, pests, and contaminants. They don’t know that traditional mechanical systems can be replaced with better heating, cooling, and ventilation systems. Nor do they realize that all of this frees the designer to include large expanses of glass and other desirable features. Once they learn all of this, the choice to pursue a Passive House becomes an easy one. Improving the existing building envelope is the key element to passive masonry retrofits. Our process starts with under-slab insulation and including a vapor barrier to create a warm, dry cellar. This vapor barrier connects to a vapor-open smart membrane installed continuously through each building level and to the underside of the roof. Outboard insulation at the roof steadies internal temperature by preventing external heat from entering the home. High quality windows that reduce thermal bridging via insulation and ensure a sealed envelope via attachment to the vapor open membrane are also key to successful passive building. Well-sealed, well-insulated homes that reduce thermal bridging enable smaller mechanical systems. Often, a simple VRF heat pump system provides adequate heat, and an ERV ensures a healthy indoor environment through constant filtered, fresh air. All-electric appliances can further reduce a building’s carbon footprint. These reductions in energy usage are imperative to opening the possibility of targeting net-zero rowhomes, where space for rooftop solar is often limited. Rooftop solar arrays are often the finishing touch to our Passive House retrofits.

CONCLUSION

As Gold Medal winner, Ed Mazria, FAIA says, “The building sector is on the verge of helping change the trajectory of the planet. The numbers are changing. We are emitting less, while building more. That is a good thing. Regardless, we must do a better job. Reusing existing buildings is a powerful step.” Beautiful envelope retrofits, electrification of HVAC systems, use of daylighting, LED lighting credits, incentives, and renewable energy options help reduce building energy consumption and design healthy, vibrant spaces. Designers can support the repurposing of existing buildings and retrofit them to be more energy efficient and cost effective for climate action.

We encourage advocacy for incentives that promote these efforts.. Research shows that when communities implement sustainable zoning ordinances, stretch codes, open space preservation, land use planning, carbon fees, circular economies, and other incentives, people will invest in the reuse of existing assets and infrastructure.. Architects are in a special place to influence and optimize the recycling of facilities. Through renovation, we gain a healthier, more sustainable, resilient environment, while maintaining vibrant communities and inspiring places. l

i Architecture 2030, data source the United Nations Intergovernmental

Panel on Climate Change Sixth Assessment Report ii Global Alliance for Building and Construction, 2021 Global Status

Report, https://globalabc.org/resources/publications/2021-global-status-report-buildings-and-construction iii New York City Mayor’s Office of Climate and Sustainability, https:// www1.nyc.gov/site/sustainability/index.page iv Lori Ferriss (2021) Sustainable reuse of post-war architecture through life cycle assessment, Journal of Architectural Conservation, 27:3, 208-224, DOI: 10.1080/13556207.2021.1943260

A. Stevens Krug, AIA, PE, LEED AP, AEE Fellow | Steve Krug, a West Chester architect well-known for his work in sustainable design, is Principal at Krug Architects and serves as Chair of the PA Climate Change Advisory Committee, appointed by the Governor. Steve is a LEED-accredited professional whose experience in sustainable design extends to award-winning public sector projects, education buildings and large commercial/residential facilities. Mr. Krug is also Co-Founder of CHP-Funder.com, WorldCogenerationDay.org, and WorldGeothermalEnergyDay.org. A former president of the Pennsylvania Chapter of the American Institute of Architects, Mr. Krug is also Chair of the Chester County Economic Development Council’s Smart Energy Initiative, and a member of the Chester County Environmental and Energy Advisory Board.

Lori Ferriss, AIA, PE, LEED AP BD+C | Lori Ferriss, Director of Sustainability and Climate Action at Goody Clancy, leads research and project initiatives for premier educational institutions that are renewing heritage campuses while advancing climate action goals. Her professional practice as an architect, structural engineer, and conservator combines broad policy development with deep technical insights to promote a culturally and environmentally sustainable world through design. She is active locally and globally through her roles on the AIA COTE Advisory Group and the ICOMOS International Scientific Committee on Energy, Sustainability, and Climate Change. She is a Co-Chair of the Zero Net Carbon Collaboration for Existing and Historic Buildings. Channing Swanson, AIA | As a native of Iowa, Channing is strongly influenced by the relationship of the Iowa landscape and its built environment. He has led the design effort of numerous private and public projects that approach the design of buildings through an understanding of the interdependence of building systems and components within their physical environments and local communities. Of importance in Channing’s work is the idea of clarity: the translation of high level aspirations into a coherent set of concrete actions that significantly improve the value of a project or process in terms of technical, economic, and environmental viability. Channing is a 1993 graduate of Iowa State University. Prior to joining Neumann Monson Architects in 2011, he began his career at Shiffler Associates Architects before spending 12 years at the influential firm of Herbert Lewis Kruse Blunck Architecture, the 2001 AIA National Firm of the Year. Since 2012, Channing has been a Principal of Neumann Monson Architects where he has helped lead the transformation of that firm. At Neumann Monson, Channing has worked on projects such as the West Campus Transportation Center at the University of Iowa, the Sukup Endzone Club in Jack Trice Stadium at Iowa State University, an operations center for MidwestOne Bank, a historic, adaptive reuse called Market One that is Iowa’s first commercial building that produces more energy than it consumes, and the acclaimed Des Moines Municipal Services Center. Current projects include ongoing adaptations to the State Historical Building of Iowa, fan experience upgrades to Hilton Coliseum at Iowa State University, and the new Des Moines Federal Courthouse.

Michael Ingui, AIA, NCARB,

Certified Passive House Designer | Michael is a Partner with Ben Baxt at Baxt Ingui Architects—a highly collaborative architectural design firm with extensive experience in residential, institutional, and commercial projects. He joined the firm in 1994 and was named Partner in 2000. Under Michael’s direction, the firm became a leader in the US Passive House movement, and most of our team are Certified Passive House Designers. Michael is active in the Passive House community, speaking at many national and international conferences including Passive House Institute’s 25th anniversary in Darmstadt, Germany. Michael and the team at Baxt Ingui have extended their collaborative efforts by opening their homes during construction to teach students, architects, tradespeople, homeowners, and developers to integrate better building techniques. In 2019, Michael founded the Passive House Accelerator as an engine to increase awareness of Passive House and support the community of Passive House builders. PHA has created a community where Passive House builders can share ideas and best practices, increasing industry knowledge and improving outcomes for clients.