Concept art by Tam Hunt, with Claude and Grok

A Bamboo Tower for Downtown Hilo

A lunch with David Sands, the fastest-growing plant on Earth, and a different way to think about what we build — and what we build it from.

I had lunch recently with David Sands, who has spent his career building with bamboo. He runs two companies out near Pahoa — Bamboo Living, which designs and builds bamboo homes, and Rizome, which manufactures engineered bamboo: the glue-laminated beams, columns, and structural panels that let you build with bamboo the way you’d build with steel or heavy timber.

Somewhere between the appetizers and the check, the conversation landed on a single image. What if we took a defunct four-story building in the heart of downtown Hilo — the one right across from Kalākaua Park — and replaced it with something extraordinary: a seven-story building framed in engineered bamboo, grown and milled right here on the Big Island. Shops and a café at street level. Four full floors of affordable condos in the middle. A couple of floors of market-priced condos up top, with the best light and the best views, helping pay for the affordable units below.

David’s reaction was immediate. “I’m getting chills,” he said.

I’ve been getting them too. Because the more I sat with the idea, the more I realized it isn’t really about one building. It’s about three problems we keep treating as separate — climate, jobs, and housing — and a single, beautiful way to take a run at all three at once.

The climate problem hiding inside our buildings

Here’s something most of us never think about: making the stuff our buildings are made of is one of the largest sources of greenhouse gas emissions on the planet.

The UN Environment Programme puts the buildings-and-construction sector at roughly 37% of global emissions. A big chunk of that is operating the buildings — heating, cooling, lighting — but a huge share is locked into the materials themselves before anyone ever flips a switch. The “embodied carbon” of our building materials — concrete, steel, aluminum — runs to about 11% of all global greenhouse gas emissions on its own. Cement alone is around 7–8%. We have, in effect, been building the modern world out of some of the most carbon-intensive substances we know how to make.

And we are about to build a lot more of it. The global building stock is expected to roughly double in the coming decades as the world urbanizes. Business as usual means pouring an almost unimaginable amount of new concrete and smelting an almost unimaginable amount of new steel — exactly when we can least afford the emissions.

But here’s the hopeful flip side, and it’s a big one. In January 2025, a study in the journal Science by researchers at UC Davis and Stanford (Van Roijen, Miller, and Davis) asked a simple question: what if, instead of emitting carbon, our buildings stored it? They found that if we replaced conventional materials with carbon-storing alternatives in new construction, the world’s building stock could lock away as much as 16.6 billion tonnes of CO₂ every single year — roughly half of all human CO₂ emissions in 2021. Buildings, in other words, could go from being one of our biggest carbon problems to one of our biggest carbon sinks.

The materials that make that possible are largely bio-based — things that pull carbon out of the air as they grow and then hold onto it. And bamboo may be the most promising of all of them.

Why bamboo, and why now

This is where David’s life’s work comes in. His pitch, boiled down, is three words: capture, store, avoid.

Capture. Giant clumping bamboo — the noninvasive kind he works with — is one of the fastest-growing woody plants on Earth. David’s figures put it at four to seven times faster than trees. A grove reaches full height in a matter of months, individual poles mature in three to five years, and a healthy stand can be harvested every year for decades without ever being replanted. All that growth is the plant inhaling atmospheric carbon.

Store. When you turn that bamboo into the beams and panels of a building, the carbon doesn’t go back into the sky. It stays locked in the structure for the life of the building — and, increasingly, beyond it.

Avoid. And every bamboo beam is a steel or concrete beam you didn’t have to make, with all the emissions that would have come with it.

If you’re picturing a tiki hut, update the picture. David showed me where this technology actually is today: a six-story bamboo “mass timber” building completed at Zhejiang University in 2024; engineered bamboo handsome enough to clad the headquarters of the Asian Development Bank. His work has been recognized with a U.S. State Department corporate excellence award and singled out by the XPRIZE carbon-removal competition. Bamboo mass timber has, in his words, arrived.

His larger vision goes well beyond one building. He thinks a fraction of Hawai‘i’s old sugar and pineapple land, replanted in giant bamboo, could turn our state from an importer of nearly everything we build with into a net exporter of building materials — and add real money to our economy while doing it. That’s a longer conversation, and the big statewide numbers are his to defend, not mine. But standing in downtown Hilo, the local version of it feels entirely within reach.

The resilience braid: local materials, local jobs, local homes

Regular readers know I keep coming back to one idea: the more we can grow, make, and build here, the stronger and more resilient our community becomes. Local food. Local power. Local transportation. This is local construction — and it ties the others together.

Think about the chain a building like this would create, all of it on our island. Bamboo cultivated and harvested in Puna. Milled, laminated, and fabricated into structural materials in a local plant. Designed and engineered by local professionals. Assembled by local construction crews. Reinforced, where needed, with basalt rebar made from our own volcanic rock. Every one of those steps is a job, and many of them are good ones. Every beam that doesn’t arrive on a barge from somewhere else is money that stays in our community and a supply line that can’t be cut by a port closure or a shipping spike.

That’s the “resilience braid” I keep talking about: local materials create the jobs, the jobs build the housing, and the housing proves the materials. One landmark project, and all three strands pull together — the same way the proposed ocean science and technology park anchors my vision for Puna’s economy.

A building that pays for its own affordable housing

The housing piece deserves its own word, because it’s the part I’m proudest of.

The building is stacked to make affordability actually work. Two floors of market-priced condominiums on top — the ones with the views over the bay — help finance three full floors of affordable homes in the middle, all above an active ground floor of shops and gathering space. The affordable homes aren’t an afterthought bolted on to satisfy a requirement and funded by someone else. The design itself pays for them. One building houses working families and homeowners together, in the heart of downtown, instead of pushing either of them out to the edges of the district.

And it does it as infill — replacing a dead building on land that’s already developed, strengthening our historic downtown core rather than bulldozing somewhere new.

Can we actually build it? Yes — with our eyes open

I’m a lawyer by trade, so I went looking for the catch. The encouraging news is that downtown Hilo is, quite literally, the one place on Hawai‘i Island whose zoning is written for real height. In the Downtown Hilo Commercial District — the same zone as the Federal Building and the old Hilo Hotel — multi-family buildings can rise to 120 feet, roughly ten to twelve stories, compared with just 45 feet most everywhere else on the island. A seven-story building needs 85–100 feet. We’d work through the county’s downtown design-review process, which for a warm wooden building in our historic, largely wooden downtown is an asset, not an obstacle.

I won’t pretend there are no real questions. Downtown Hilo sits near the bay, and our tsunami history (1946, 1960) is not something you wave away — the site’s flood and inundation setting has to shape the ground floor and the structure. Engineered bamboo is still a newer building material that would go through the established review process for innovative materials, alongside a licensed structural engineer (the good news: light, flexible bamboo tends to do well in earthquakes). These are the ordinary challenges of turning an inspired idea into a permitted building. None of them is a reason not to start.

Why I’m writing about this

I’m running for the State House because state support for a homegrown engineered-bamboo industry would be very helpful. Building codes modernized to welcome bamboo and mass timber. The kind of demonstration project that proves something is possible and pulls private investment in behind it.

But mostly I’m writing because I think we’ve gotten used to thinking small about what our island can do. A gorgeous tower of Big Island bamboo, in the heart of our county seat — storing carbon, creating jobs, and housing our own families — is the opposite of thinking small. It’s the kind of thing that makes people lean in, the way David and I did over lunch.

Bamboo grown on the Big Island. Built by people who live here. Homes our families can afford, in the heart of our county seat. That’s the kind of future worth building — and worth fighting for.

I’d genuinely like to know what you think. Reply here, or find me at Hunt4House.com.

The concept rendering above is illustrative — a picture of an idea, not a final design. The conversation, and the work behind it, is very real.

[Claude helped to write this blog]