The state of alternative building materials

The latest in real estate technology

February 28th, 2025

Building materials: New paradigms meet age-old foundations

Home builders and developers continuously evaluate alternative building materials, whether to manage budgets, improve resilience, reduce waste or streamline construction. Alternatives can range from replacements or buffers for the world's most widely used materials, like steel and cement, to entirely novel concepts.

Chief among the metrics stakeholders painstakingly evaluate are price, performance, and production capacity. Safety and compliance with codes and standards, production scale, and consumer preferences matter, too. Further, as disaster risks raise demand for more resilient building materials and the specter of rising global tariffs and other supply chain disruptions raise costs and can limit supply availability, appetite for alternatives grows.

Given the complex dynamics at play, let’s investigate whether, where, and how fast this market is changing.

1. Steel and concrete–the age-old foundation

There's no sidestepping the central foundations of the built environment. In the span of a few centuries, humans have deployed so much concrete there's more of it on Earth (alongside other 'basic' building materials, like steel and asphalt) than there is biomass (think plants and trees).

Source: Anthropogenic mass vs. biomass during the 20th century, via Elhacham et al 2020

Here’s another striking stat: China poured more concrete between 2011 and 2013 than the U.S. did in the 20th century.

It's impossible to imagine the built environment, real estate, and construction without concrete and steel for many reasons. Safety, cost, and performance will always reign supreme as the central pillars of building material evaluation. Then there’s a labyrinthine landscape of building codes and safety and performance standards, all of which vary by factors like geography and building type. All those variables—particularly price and performance—present a steep hill to climb for companies trying to introduce alternatives to the world's most ubiquitous building materials.

Nevertheless, there is momentum for startups that develop alternative production methods for steel, concrete, and cement-like materials. Together, steel and concrete production account for ~15% of carbon dioxide emissions globally every year. Regulations concerning embodied emissions are one driver of demand, but alternative materials won’t win on “going green” alone. They must also provide builders with benefits like faster construction processes and reduced costs while performing as well (or better) than traditional materials.

Take Brimstone, a Fifth Wall portfolio company developing “deeply decarbonized” cement and other materials. In 2023, it received third-party certification that its cement "meets or exceeds" ASTM C150 standards for Portland cement (the most common cement type). ASTM C150 is a seminally important industry standard that's effectively a ‘rulebook’ for Portland cement, setting chemical and physical requirements. Still, as noted above, there's a lot more for companies like Brimstone to prove as they try to overhaul the most ubiquitous building materials. As Brimstone’s CEO, Cody Finke, emphasizes:

“The construction industry is inherently risk-averse, which can be understood by the relative low cost of cement compared to the extremely high cost of material failure. The risk-adjusted cost of using a novel material simply is not worth any reward.”

That said, not all change requires wholesale innovation. Simply recycling concrete could help on both cost and sustainability fronts by turning demolition debris from a wasted resource into an asset. However, concrete recycling is not a common practice, given challenges inherent to managing quality consistency for concrete aggregates. Recycling steel, meanwhile, is common; in fact, steel is the most recycled material globally because recycling it offers significant energy savings.

2. Challenging the heavyweight incumbents: New (and re-imagined) building material alternatives.

While the world of steel and concrete evolves (slowly), other alternatives are getting a fresh look. Mass timber, for instance, is a rising star in the U.S. Google recently unveiled its first mass timber building in the Bay Area, featuring a design with 96% fewer embodied emissions compared to an equivalent steel and concrete structure. Ultimately, however, the goal was to create a space that "improves employee wellbeing and supports the community."

Perhaps more importantly to most stakeh...