Innovation Is Greening US Multifamily
Sustainable technologies find their way into all levels of construction and design—and at every income level.
The sustainability push in multifamily is boosting complex and promising new technologies. A surprising detail? This innovation is not only transforming luxury construction and design but crosses the quality spectrum to include affordable housing.
One innovation commanding a lot of attention is Passivehaus, or Passive House. This building standard emerged in Sweden and Germany at the end of the last century. Early projects were inspired by Canadian and U.S. designs that incorporated energy efficiency during the 1970s energy crisis. The style quickly gained international popularity.
Passive House properties create a super-insulated building envelope, allowing the conservation of heating and cooling. The goal is to seal as tightly as possible. And while this is easier to achieve with new construction, older properties can get there, too.
For example, most buildings that architecture firm Quinn Evans works on use Passive House standards, according to Brandon Schultz, principal at the firm.
“You’re trying to make something that’s super-efficient and holds its temperature for a really long time,” said Schultz. “That requires really great detailing. We do a lot of energy models throughout the process. We’re really focusing on air-sealing around all windows and any penetrations.”
READ ALSO: How Passive House Standards Benefit Affordable Projects
As air can escape around and through them, windows are at the center of sustainability efforts in design and construction. “Often, if we can afford to go up to a triple-glazed window, in addition to being super-efficient, you’re seeing some benefits from a sound transmission standpoint,” Schultz added.
Electric avenue
Electrification and the introduction of high-efficiency heat pumps also doubles down on sustainability. Quinn Evans is fully electrifying all new builds, Schultz pointed out, something that includes stovetop ranges, heat pump systems for heating and cooling, and in most instances, heat pump water heaters.
Electrification also offers the opportunity to replace existing combustion equipment, such as gas ranges, in units that may not have had adequate exhaust ventilation. Improved air quality is one of the benefits, said Schultz. Energy recovery ventilators are also being incorporated into an increasing number of projects to improve indoor air quality and energy and heat recovery.
“There are a lot of opportunities for electrification,” added Schultz. “It is definitely not cheap to go in and retrofit a whole high-rise building and have to run a new electrical backbone up through the building. Now, with (the Inflation Reduction Act) funding, it’s a lot easier. There are a lot of funding sources out of (HUD) for substantial rehabs.”
A 2021 report from McKinsey that warned that given “typical asset lifetimes of 30 to 130 years, we cannot wait to replace products at the end of their life cycle if we are to meet climate-change-mitigation targets by 2050. With roughly 80 percent of the predicted building stock for 2050 already in existence today, there is a huge need—and opportunity—to retrofit existing assets.”
Carbon, construction-stage
Embedded carbon is a concern when it comes to weighing the pros and cons of retrofitting and upgrading an existing structure or beginning a project anew. Embracing tenant-in-place projects, where properties are improved while residents stay put, is one way to avoid displacement while working and also avoiding the added environmental impact of demolishing and rebuilding. Adaptive reuse projects are also important in avoiding potentially unnecessary rebuilds.
Sustainable tech kicks in long before a building gets its wiring or its heating and cooling systems, since a property’s carbon footprint is already being laid even as it is being developed. Building materials are one of the biggest determiners of how big that footprint will ultimately be, and in most U.S. markets, concrete is still king.
Concrete is everywhere and unlikely to be replaced anytime soon, according to Mukesh Parikh, managing principal at DeSimone Consulting Engineering. “I have not seen anything lately that is sort of a game-changer in terms of the construction industry,” he remarked. “Concrete will continue to be the primary material, at least for the higher-rises and a lot of transportation roadways.”
While DeSimone constructs properties with various structural systems, including timber, structural steel and masonry blocks, many projects still use concrete. “Our focus primarily has been, really, on how to make concrete better,” Parikh pointed out.
“Cement is one of the largest carbon emission products out there,” he added. The use of concrete is a market-driven decision, he further noted, and one of the firm’s main sustainability-focused goals is the utilization of less concrete in projects that call for it. “Over the years, the technology has improved in terms of concrete manufacturing to the point where the concrete strength has gone up almost double in the last five to seven years.”
READ ALSO: What Are the Construction Technologies of the Future?
The main products that have been used to lower the cement content of concrete are fly ash, a byproduct of coal production, and slag, refuse from steel manufacturing.
“These two products have the properties to replace cement,” said Parikh. “Let’s say the mix has 100 pounds of cement. We can do 50 pounds of cement and 50 pounds of fly ash. All of a sudden, your concrete has half the cement. Most of the concrete manufacturing plants have this implemented, so it’s available.”
That’s not to say, of course, that even more sustainable methods for reducing cement content in concrete aren’t on the horizon. “There’s a new product out there that’s recycled glass,” mentioned Parikh. Until that’s perfected, however, the materials for new buildings still contain a reminder of a not-too-distant coal-fueled past.
Concrete is not the only product getting a makeover. “We’re doing the same thing with structural steel,” said Parikh. “We’re using higher-strength structural steel. Even the reinforcing in concrete is higher-strength now. It just allows us to use less of it.”
From luxury amenity to affordable must-have
The IRA provides billions in loans and grants for upgrades to subsidized apartments as well as single-family homes, Claire Kramer Mills, assistant vice president & director of community development analysis, and Jacob Scott, community development analyst, both with the Federal Reserve Bank of New York, wrote in a 2022 report focusing on sustainability in affordable housing. “These funds have the potential to catalyze action at scale, especially when paired with other public incentives and private capital,” they observed. “Financial institutions can play a role by devising new financial products to fund the transition and by helping to align incentives among stakeholders.”
While sustainability features have long been touted as luxury amenities, affordable housing may very well be the true leader when it comes to standards. It might seem intuitive to believe that affordable properties are lagging, but the reality often points in the other direction. This has a lot to do with legal requirements.
“In many of the states that we’ve been working in, affordable housing has been sort of leading the way and then all the other market sectors have caught up,” Schultz observed.
There are “definitely hurdles” to making affordable housing communities comparatively sustainable. “It depends a lot on financing and the opportunities that are available to actually figure out a way to pay for some of the features that we’re trying to get into properties,” Schultz added.
Each state has its own requirements for low-income housing, something that ends up dictating many decisions. Most states offer 9 percent and 4 percent tax credits for low-income housing. “The 9 percent credits are competitive, so typically, you have developers who are promising that they’re going to do more from a sustainability front. Most of the (qualified allocation plans) provide additional points for higher levels of sustainability.” This can include promises to meet LEED Gold criteria or achieve full Passive House standards.
“I think that the statewide tax credit programs have definitely incentivized doing more sustainable, affordable housing development,” said Schultz. “It’s just uneven across all of the states.”
There’s always room for improvement—and the existing affordable stock could have more difficulty advancing due to financial constraints. However, as new properties are built and as new equipment and tech are introduced to communities new and old, the greening of the rental market has a clear, albeit at times narrow, path forward.
