No matter how you slice it, buildings are serious climate change drivers. Every component of the so-called built environment — from off-site materials production and construction to electricity and maintenance — comes at a steep environmental cost. The sector is responsible for nearly 40% of energy-related greenhouse gas emissions globally, according to the International Energy Agency, an intergovernmental group.

In the coming decades, the built environment’s carbon footprint is poised to grow with the sector itself, making it both a critical and lucrative target for climate-focused startups. This is the backdrop for Plantd, which raised a $10 million Series A to replace panels that are nearly ubiquitous in single- and multi-family homes.

Plantd aims to supplant materials such as oriented strand board, or OSB, which is an engineered panel made of wood strips and adhesives. You may not know them by name, but you’ve likely seen them before — in floors, roofs, furniture, and so on. The industry calls OSB a sustainable plywood alternative, because the wood strips don’t need to come from old-growth forests. Still, Plantd thinks it can do better with its own panels, which are made from a “proprietary blend of perennial grasses that grow exceptionally fast.”

Reached by TechCrunch, the startup declined to disclose the names of the woody grasses. But judging by an image on the startup’s website, they look kind of like bamboo.

“Unlike trees used for engineered wood products which are harvested after growing for 10–12 years, our biomass regrows and is harvested every year from the same acreage,” said co-founder and CEO Josh Dorfman. “This enables Plantd to capture vastly more atmospheric carbon faster than trees can and do so using less land.”

Insurance-focused investor American Family Ventures led Plantd’s Series A, while IDEA Fund Partners also chipped in on the round. Earlier investors in the startup include Twitter co-founder Biz Stone and Palmetto solar CEO Chris Kemper, said Plantd.

The startup told TechCrunch that it raised its $10 million Series A at a $65 million postmoney valuation.

Plantd said its panels are stronger than traditional panels and will deliver serious environmental upsides, but the startup has not yet proven its claims at scale (hence the Series A). Dorfman told TechCrunch that Plantd is currently producing prototypes and is “not yet in the market.”