What does it really take to build homes that are beautiful, efficient, resilient, and responsible?

In this special 100th episode of Home Green Homes, Izumi Tanaka welcomes Steve Glenn, founder and CEO of Plant Prefab, for an in-depth conversation that weaves together architecture, sustainability, entrepreneurship, and climate action.

Steve traces his path from an early love of architecture to founding LivingHomes and later Plant Prefab—companies created to challenge the waste, inefficiency, and environmental impact of conventional construction. He explains what truly sets Plant Prefab apart: customized architectural design, a purpose-built factory capable of both panelized and modular construction, and a mission-driven commitment as a certified B Corp and public benefit corporation.

The conversation also dives into Plant Prefab’s work supporting communities rebuilding after devastating Southern California wildfires, and why prefab construction can offer faster, more predictable, and often more cost-effective rebuilding solutions.

Along the way, Steve addresses common misconceptions about prefab homes, shares what homeowners should prioritize when designing for climate resilience, and reflects on leadership, scaling a values-driven company, and what he hopes the future of housing can become.

This episode is especially relevant for homeowners, home dwellers, architects, builders, developers, and anyone curious about how housing can be part of the climate solution.

• Prefab ≠ mobile homes: Plant Prefab homes are legally and structurally equivalent to site-built homes and cannot be excluded from zoning, financing, or insurance.
• Energy matters most: Over a home’s lifetime, operational energy use has a bigger climate impact than materials—efficiency and solar should be top priorities.
• Time is money: Faster, parallel construction can significantly reduce carrying costs, rent, and uncertainty—especially important in rebuild scenarios.
• Design and sustainability go together: High-quality architecture and environmental responsibility are not mutually exclusive.
• Rebuilding after disaster is an opportunity: Prefab can help communities recover faster while building more resilient, future-ready homes.
• Mission-driven businesses face real challenges: Scaling sustainably takes persistence, patience, and long-term vision—but the impact compounds over time.

Chapters

• 00:00 Personal Impact and Vision for the Future

“So when I think about a future that is solving climate, I think about raising our quality of life. I think about more inclusive cities with wonderful parks, and it's a fantastic mass transportation that's really considered a luxury good because whether you're the wealthiest person in that city or the poorest, you all want to be on the same subway or the same bus because it's simply the best way to get around and everyone enjoys these types of amenities.There are examples of that all over the world.  We try and bring those to light. And that is my vision for what the future starts to look like.”

Josh Dorfman spent time in China in the 1990s, which opened his eyes to  environmental issues and the impact of rapid industrialization and consumerism. When he returned to the U.S. and went through a phase of environmental activism before deciding to focus on shifting consumption towards more sustainable products.  He started an eco-friendly furniture company called VivaVie in 2004, which led to the creation of his "Lazy Environmentalist" media brand.

During the pandemic when supply chain issues made it difficult to source sustainable materials for his previous furniture company, he developed Planted - Josh's current carbon-negative building materials company.  They identified fast-growing perennial grass as a potential replacement for traditional lumber and engineered wood products.  They worked to vertically integrate the entire supply chain, from growing the grass to manufacturing the building panels, and partnered with major homebuilder D.R. Horton to secure a large order for their carbon-negative panels.

Josh then launched a media company, Supercool, after stepping down as CEO of Planted to focus on sharing stories of climate innovation and solutions.  Supercool aims to highlight commercialized, scalable technologies and initiatives that are improving people's lives while addressing environmental challenges. He shares his vision for a "Supercool future" that involves raising quality of life through inclusive, sustainable cities and infrastructure.

“We’re always inspired by nature and using nature as a starting point. So we can use the most advanced technology whether it’s robotics or parametric design using algorithms, AI.  Regardless of the technologies our goal is to create something that’s beautiful and it’s just works as far as the simplicity.  And there’s kind of a synergy in the work we do.  So we’re hoping to use this advanced technology beautiful forms in the nature and having everything work together really well.”  - Joseph Sarfian

Joseph Sarafian and Ron Culver, are the founding partners of architectural firm Form Found Design. Joseph has a background in computational design and parametric modeling, while Ron has experience as an architect, contractor, and musician. They met in graduate school and decided to start their firm together, combining their complementary skillsets.

Form Found Design has developed several innovative construction techniques, including using robots to cast custom concrete structures and a computational framing system that allows for mass customization without added cost. They have used these methods for projects like a 15-foot tall concrete structure for Amazon, as well as residential homes.

In response to recent wildfires, Form Found Design has focused on designing fire-resilient homes using non-combustible materials like metal, insulated panels, and cross-laminated timber. Their goal is to create homes that are more durable, energy-efficient, and sustainable compared to traditional wood-framed construction.

The main challenge Form Found Design faces is educating contractors and homeowners about their innovative construction methods. However, they believe the demand is there, as people are increasingly seeking more resilient and sustainable building solutions. Their overall vision is to use advanced technology like robotics and parametric design to create beautiful, nature-inspired architecture that is also highly functional and efficient.

@FormFoundDesign

“I think there's a whole new awareness right now after these fires in LA, at least for people who live in California of like, just actually how toxic our whole houses are.  So, you know, the answer for some might be, “oh, I was going to buy a new couch and I'm going to buy a couch that's cotton instead of like plastic,” you know, just smaller things.  And, yeah, the more people that could be building a whole house out of natural materials right now, that's amazing.”  - Sasha Rabin

Sasha Rabin has a long history with natural building, stemming from her father's early interest in straw bale construction in the 1990s. This sparked Sasha's passion, leading her to study environmental design and eventually focus on earthen building methods like cob, adobe, and light straw clay. She founded Earthen Shelter as a platform to teach workshops on these techniques, which she sees as an important part of creating more sustainable and healthy built environments.

Sasha discussed the challenges of getting alternative building materials permitted, especially in high-seismic areas. While there are now code appendices for some natural building methods, Sasha and organizations like Quail Springs, where she is involved, have had to do extensive testing and work with local officials to demonstrate the safety and viability of these materials. Looking to the future, Sasha envisions a multi-pronged approach, from simple retrofits using earthen plasters to whole cob or adobe structures, as crucial for rebuilding more resilient communities.

“The secret is cost shifting.  That’s the secret. So we shift the cost from expensive mechanical systems into the quality of the building shell, of the building envelope.  We have what we call a super-insulated building envelope.  We have triple-glazed windows. We have insulated frames.  They get installed in a certain fashion.  And we basically take… we beef up the building envelope.  it’s super-insulated that means insulation is cheap.  Insulation is the cheapest building material on the planet.  It’s much less expensive than batts.  That’s really the issue.” - Joaquin Kar

Joaquin Karcher is a founder/owner/principal architect for Zero E Design based in Taos, New Mexico.  The discussion centered on Joaquin’s expertise in eco-architecture and his work with Zero E Design, particularly focusing on cold climate architecture in northern New Mexico. Karcher shares his journey from his early passion for eco-architecture in Germany to his current projects, emphasizing the importance of achieving carbon neutrality in buildings by 2030. He highlighted his collaboration with the Navajo tribe to improve housing using local materials and labor, as well as his insights gained from the Passive House Institute in Germany. The conversation also delved into the principles of passive house design, its affordability in California, and the benefits of enhancing building envelopes to create energy-efficient homes.

Karcher discussed the resilience of passive houses in extreme weather and fire-prone areas, suggesting specific materials and techniques for safety. Although he has not yet worked on redesigning homes affected by wildfires, he expressed a vision for affordable, resilient zero energy buildings, particularly through offsite construction methods like panelized construction. 

Healthy home supports your health, in my opinion, from the air we’re breathing, the materials around you, it's designed to promote your health and it prioritizes air quality, has items that are made from non-toxic materials, and it actively reduces toxins, you can actively reduce toxins when you have practices that support a healthy home. So all that is also going to be good for the environment typically. - Karen Bloom

Karen started her career as a consumer protection attorney, fighting against companies that failed to warn consumers about the dangers of chemicals in their products. She later developed a mysterious illness that was eventually diagnosed as Lyme disease and mold toxicity, which made her highly sensitive to chemicals and toxins. This experience inspired her to focus on creating non-toxic living spaces to help others who have been in similar situations.

A healthy home supports your health by prioritizing air quality, using non-toxic materials, and actively reducing toxins. While a green home focuses on environmental sustainability, the two concepts don't always fully align. Karen explained how some "green" technologies like LEDs and EMFs can actually be harmful to health, and emphasized the need for solutions that protect both the environment and human health.

Karen provided several specific recommendations for creating a healthier home, including using air purifiers, high-quality HVAC filters, natural cleaning products, non-toxic furniture and mattresses, stainless steel or glass food storage containers, and proper ventilation when cooking. She also discussed the importance of being mindful of the products we bring into our homes and their potential impacts.

Karen explained that her business, Natural Haven, offers in-home or virtual consultations to assess a client's home and provide customized recommendations for improving indoor air quality and reducing toxin exposure. She also creates educational content and free guides to help people make their homes healthier.

When asked about recommendations for protecting against EMF exposure when outside the home, Karen expressed skepticism about the effectiveness of many EMF shielding products on the market, noting that she has tested many and found them to be ineffective. She suggested exploring professional EMF assessments and mitigation strategies instead.

"The fact of the matter is your heating  your home and cooling your home and heating your water are the two biggest loads to your electric bill. They cost the most in in your home.  So this is an opportunity to yes decarbonize and do right for the environment and our grid but also for energy usage.  And the products are there.  There's more and more coming for sure. " - Anita Singha

The much anticipated rebate part of the Inflation Reduction Act, HEEHRA, Home Energy Efficiency Rebate program launched in California in November, 2024.  Anita Singha, the Senior Marketing Manager for the Switch Is On, the administrator of the financial incentive programs in California explains how this rebate program works and how to navigate it.  

She explains the program provides rebates of up to $8,000 for low-income households (80% or less of area median income) and $4,000 for moderate-income households (80-150% of area median income) to install heat pumps and heat pump water heaters. The rebates are paid directly to the contractor, and consumers must use a HEEHRA-qualified contractor to be eligible.

Anita walks through the steps for consumers to verify their income eligibility and find HEER-qualified contractors through the Switch Is On website. This includes using an online income verification tool, getting a certificate of eligibility, and then contacting multiple contractors to get quotes.

Izumi shares her experiences trying to help low-income homeowners, particularly those in remote/rural areas, navigate the HEER program. She highlights issues like lack of HEER-qualified contractors in certain regions, contractors being unfamiliar with heat pump technology, and complexities around mobile home and rental properties. Anita acknowledges these challenges and discusses efforts to expand contractor training and outreach, and reassures that the $450 million in HEER funding allocated to California is secure, even with a potential change in federal administration. However, she notes that the rebates may not last indefinitely, so consumers are encouraged to act quickly.

Additional clarifications:  California state is launching the rebate program with one appliance at a time, mainly focusing on the heat pump systems.  The first phase was for heat pump HVAC system, in which low-income households can get it installed for free although the homeowners may have to cover a difference if the cost of installation exceeds $8,000.  Qualified householders can apply if you live in a condo, 2-4 units buildings, ADU and Junior ADU.  If you live in a mobile home, you can apply as long as you’re on a foundation and not have an axle or license number. 

We are focused on incentives for home upgrade projects.  We’re focused right now on residential space.  If anyone is listening or you might have applied for a rebate program in the past, like an appliance rebate program through a government agency or utility, it oftentimes can be quite challenging.  So we provide an end to end solution to make it very easy for folks to pre-qualify projects for all available incentives as well as then to claim the funds. And you can think of us as kind of a TurboTax for electrification rebates.  - Aimee Bailey, Rock Rabbit

Rock Rabbit was founded in 2022 by Aimee Bailey, co-founder and CEO, with her co-founder,  building on concepts Bailey had been developing for years in her previous roles in the energy sector, including roles at the Department of Energy, utilities, and government agencies, with a focus on designing and deploying incentive programs.  The company's mission is "Future-proofing homes made easy and affordable for everyone," reflecting their commitment to accelerating the energy transition in the residential sector.

Rock Rabbit provides an end-to-end solution for contractors and homeowners to easily navigate and claim rebates for home electrification projects. The platform integrates multiple databases, including incentive programs, authority having jurisdiction (AHJ) registries, and community choice aggregation (CCA) information, to simplify the complex landscape of rebates and eligibility requirements.

The company addresses three key pain points in the rebate process: incentive discovery (finding available programs among hundreds of options), navigating eligibility requirements (interpreting complex program rules), and streamlining paperwork processing (reducing administrative burden for contractors and homeowners).

Rock Rabbit works primarily with contractors as their main user base, but also collaborates with utilities and government agencies to streamline rebate programs. This dual approach allows them to improve the rebate process from both the implementation and administration sides.

There's a significant labor shortage in the HVAC industry, with estimates suggesting a gap of hundreds of thousands of technicians needed to meet climate targets. Rock Rabbit aims to alleviate this by making rebate processes more efficient, allowing contractors to focus more on installations and less on paperwork.

For inquiries, contact: [email protected]

If you’re thinking about starting an Eco-Village, you wanna know, essentially you want to know what are the issues with soil, with air, with water, in your bio-region, in the ecological region that you live in; what are the relationships that you have with your elected officials that have the power over the area where you want to make this happen; who are your neighbors, and what kind of relationships you have with those neighbors whether they’re rural, farm neighbors, or whether they’re urban neighbors on your block. - Lois Arkin

Lois Arkin shares her personal journey, from growing up in a close-knit, nature-filled neighborhood as a child, to moving to California with her husband, studying anthropology, and eventually finding her calling in the cooperative and intentional community movements. This led her to found the Cooperative Resources and Services Project (CRSP) in 1980, which laid the groundwork for the Eco Village LA concept.

She explains how she came to the idea of creating an "eco village" - a cooperative, environmentally-focused community - after hosting public forums on different types of cooperatives. She describes the process of acquiring the first Eco Village LA building in the 1980s, and how the community has grown to encompass three buildings and a land trust over the decades.

As she outlines, the key criteria that define an eco village, as outlined by early eco village pioneer Robert Gilman - includes being human-scaled, full-featured, closing the waste loop, supporting healthy human development, and being sustainable long-term. She explains how Eco Village LA aims to embody these principles, while also maintaining a diverse community in terms of income, ethnicity, gender, age, and household composition.

Lois candidly shares the conflicts and challenges the community has faced over the years, including periods of intense interpersonal tensions. She describes how they eventually implemented a formal conflict resolution process, requiring members to first try to resolve issues one-on-one, and then seek mediation through a community conflict resolution committee if needed.

Looking ahead, Lois talks about Eco Village LA's upcoming plans, including creating a pedestrian plaza on their main street, developing an urban farm, and continuing efforts to remove more housing in the surrounding neighborhood from the speculative real estate market. She emphasizes the broader goal of transforming the real estate industry's mindset from "maximum return on investment" to a "fair return on investment" to improve housing affordability and quality of life.

Other resources mentioned:  

Foundation for Intentional Communities

The Cohousing Association of the United States

“And what we did was, ‘let’s combine the performance of heat pump, off the shelf heat pump, heat pump water heater, with thermal storage with really really smart controls, and you can reap the benefit of that heat pump by shifting the load to the middle of the day and giving you a heat and hot water whenever you need it.”  - Jane Melia

Jane Melia, Co-founder and CEO of Harvest, the smart thermal battery system explains the genesis of Harvest.  She discusses the limitations of traditional heat pump systems and how Harvest combines a heat pump with thermal storage and smart controls to decouple the time when heat is generated from when it is used, allowing the system to take advantage of cheaper, cleaner electricity.

Jane provides a detailed overview of how the Harvest system works. It uses a heat pump water heater, a thermal battery (hot water tank), and smart controls to optimize when the heat pump runs to take advantage of renewable energy and off-peak electricity rates, while still providing heating and hot water on demand.

Jane discusses the cost of the Harvest system, noting that it is comparable to a median heat pump system but with higher performance. She explains the various incentives and tax credits available, including the 30% federal tax credit, that can make the system cost-competitive with traditional gas heating and water heating. She also discusses Harvest's efforts to work with contractors and property owners to drive broader adoption.

Jane and Izumi discuss the future of home heating and cooling, with Jane envisioning a future where thermal storage becomes a standard feature of heat pump systems to better leverage renewable energy and support grid decarbonization. They also discuss the policy changes, such as bans on new gas furnaces, that are helping drive the transition to clean heating solutions.

harvest.green