Think Swiss knife with Cocoon9's prefabs: The furniture, appliances, and storage areas open up and fold away into walls, floors, and ceilings to maximize space. As for sustainability, the models incorporate such sustainable materials as F.S.C. certified bamboo and insulated glass with thermally broken aluminum frames. (The term "thermally broken" refers to the window's construction: The aluminum frame window is fabricated with a barrier in between the inside and outside window frames, which prevents the thermal energy loss.) All of the models are also equipped to accommodate solar panels and roof gardens.

2. Deltec: Renew Collection 

Deltec has been designing and constructing prefabs across the U.S. since the late 1960s. Currently, the Asheville, NC, company is being recognized for its energy-efficient prefab models. It's also a certified B Corporation. Deltec’s new Renew Collection is getting a lot of buzz. The models are prefabricated, panelized homes with a passive solar layout that can be net-zero ready. Homebuyers receive energy modeling based on the weather in the homeowner's region, and the company will customize the construction based on-site, climate, and homeowner needs. The Renew prefabs are certified as Zero Energy Ready, Indoor airPLUS, and as ENERGY STAR homes.

P.A.T.H. utilizes renewable energy sources for heating, cooling, and ventilation. P.A.T.H. homes come renewable-energy ready to install solar panels, heat pumps, wind turbines, rainwater collector systems, and other essential elements of sustainable design. Clients can opt for packages that turn the P.A.T.H. home into a zero-energy or even positive-energy home.

As Starck told Rise, "Building your own house can be extremely risky: we know when it starts, but not necessarily when it ends, or how much it will cost. With P.A.T.H. and thanks to the industrial production of prefabricated components, in six months and for a defined budget, anyone can access a home." 

5. Alchemy Architects: weeHouse

In 2003, Geoff Warner, founder of Alchemy Architects in St. Paul, Minnesota, started with a seemingly simple idea: To design a sustainable prefab home that clients could buy in an easy, off-the-shelf way. After the first award-winning weeHouse in Wisconsin was built, things didn't go as planned. "With the weeHouse, we originally thought clients would choose a plan, and we could execute it with a factory partner in about three months," Warner says. "It didn't work that way. The weeHouse modules we showed were just starting points for customized homes."