“The greenest building is the one that is already built.”
Carl Elefante, former president, American Institute of Architects.
As the world grapples with the urgent need to address environmental concerns and reduce carbon emissions, adaptive reuse has emerged as one approach to sustainable development. Adaptive reuse is not a new idea. The practice of preserving existing buildings and giving them a second life has been used in cities with older and historic buildings for decades. Adaptive reuse involves repurposing existing buildings for new functions and avoids the need to build new structures from scratch. This practice preserves historical and architectural heritage and significantly saves valuable resources.
Understanding Embodied Energy
In the United States an estimated 200,000-300,000 structures are demolished every year. The materials—wood, metal, glass, concrete and more—average around 534 million tons sent to landfills annually. And when all that material is thrown away, so is the energy and water it took to make it. When we choose to reuse existing buildings, we preserve the energy embodied in the structure.
Embodied energy refers to the total energy consumed throughout a building’s life cycle, encompassing all stages, from material extraction and manufacturing to construction, operation, and eventual demolition or adaptive reuse. Every structure, whether residential or commercial, contains embodied energy. Constructing new buildings requires massive amounts of virgin resources, all of which contribute to greenhouse gas emissions. In contrast, adaptive reuse repurposes the existing embodied energy of a building, making it a highly sustainable alternative.
Trends in Adaptive Reuse
There are plenty of examples of adaptive reuse, and the vast majority lean towards spaces that are older and with certain characteristics. These buildings are often worth saving because of their unique qualities and the superiority of the materials used to build them.
In parts of the U.S. where pre-1940s buildings are prevalent, adaptive reuse is both possible and desirable. Industrial warehouses, factories, and churches are finding a second life as high-end loft apartments, galleries, and community spaces. These new uses breathe life into the surrounding neighborhoods by attracting new residents and businesses.
Locally, there are interesting adaptive reuse projects that follow this general idea. Located on 5th and Main in Springfield is the 112-year-old Rivett Building. Currently under construction, a new structure will be inserted inside the existing single-story building to support additional stories above. Once completed the building will offer three commercial spaces and 12 new apartments.
Another adaptive reuse project in Springfield involves a school building that was built in 1921. Located at 525 Mill Street and owned by the Springfield School District, the building was slated for demolition. Instead, it was sold for redevelopment and will soon be converted into 40 new apartments.
A notable example in Eugene is the EWEB Steam Plant building, located next to the Willamette River on the Downtown Riverfront property. Built in 1931 to meet the area’s growing demands for power, the Central Heating Company used the facility to supply steam to downtown office buildings. At the turn of the century, a decision was made to decommission the plant and PeaceHealth, the last remaining customer, was disconnected from the system in 2012. In January 2022, the Urban Renewal Agency of the City of Eugene approved terms for the redevelopment of the Steam Plant. According to the City’s website, “The [redevelopment] team proposes to save and adaptively re-use the Steam Plant, transforming it into a vibrant mixed-use center that maximizes public participation and enjoyment.” The proposal includes plans for an ‘indie’ hotel, large indoor/outdoor restaurant, and office spaces upstairs.
Can Adaptive Reuse of Office Space Solve the Housing Crisis?
According to Britni Jessup, Principal at Rowell Brokaw Architects in Eugene, there is a lot of local interest in adaptive reuse. “The pandemic has created a shift in the way that people work, and we are seeing less demand for large office remodel projects. Throw in the current housing shortage and affordability, and it makes sense to look at these spaces as a potential solution. But it’s not without challenges, or we’d be seeing these projects successfully completed at a higher rate” adds Jessup.
While adaptive reuse seems like a big opportunity for existing buildings, converting office space into residential units can come with significant hurdles. Office buildings are designed with distinct programmatic requirements, systems distribution, and under specific code requirements can vary greatly from the way a new multi-family project would get built. Other challenges include changes to building occupancy and use, floor layouts and dimensions, mechanical, electrical, and plumbing systems, and life safety and egress constraints.
Building codes require fire separation between commercial and residential uses in mixed-use buildings. This can make the conversion process more complicated and costly. Though it can be challenging, changing occupancy within a building is not insurmountable and, according to Jessup, City of Eugene officials have been supportive of efforts that increase the opportunities to add housing, especially in the downtown core.
“The bigger challenge with adapting office space to residential use is the way that office space is typically built.” says Jessup. Office buildings usually have central services and distribution—think bathrooms, HVAC, etc.—and large, flexible, open floor plates suited for dividing in different ways as the demand changes. Residential buildings are designed with more distributed systems and unit dividing walls typically don’t change much over the life of the building. Redesigning the layout to accommodate these needs may involve significant renovations. Jessup also points out that the floorplans for office buildings tend to be thicker in the middle with less access to daylight, a non-negotiable for a housing unit. The result can be desirable, though, with bigger, unique unit types that new construction projects wouldn’t be able to afford.
“The trick to getting these projects built is to get the cost of the project to pencil with a potentially higher unit size and lower overall unit count. There’s a financial reason larger units don’t get built with the rising costs of construction, the rental rates the market can handle, and the risk of offering unique unit types and amenities that aren’t tested in the market. Places like New York City have been dealing with these issues for decades—and you see some ‘creative’ solutions to these same issues through their available housing stock. Not all of the creative solutions end up with livable or even code-compliant units, though.”
Mechanical systems in office buildings are also complex. Heating and cooling systems optimized for office environments tend to be more centralized and plan to cover larger square footage. Depending on when the existing building was constructed, there may also be different air flow and fresh air requirements triggered by the change in use as well as different applicable codes. Adapting these mechanical systems can create significant changes in order to create individual controls for independent residences. And the same can be true for plumbing, electrical systems, and fire sprinkler systems.
Though not every building has the potential to be converted to housing, adaptive reuse is here to stay. The practice has the potential to preserve historic places, maintain the character of downtown areas, reduce urban sprawl, and promote sustainable re-development.
Read the entire Fall 2023 Edition of UsedNews here.
Edited: The print version and an earlier digital version of this article incorrectly stated that the EWEB Steam Plant is located next to the McKenzie River.