Seoul architect Byoung-soo Cho designed the sofas in his urban dream house to resemble building blocks.

Seoul, population 26,100,000. The densely populated South Korean capital is the world's most high-tech megacity, with wireless access available nearly everywhere in the city limits for a small fee.

Incheon International, Seoul

Clad in copper panels that Holl had fabricated by the Kansas City, Missouri, company Zahner, the house is daylit by a host of rectangular skylights (inspired by the musical staff) punched through the roofs and the pool’s floor.

A Seattle family tasked Atmosphere Design Build with creating a sustainable dwelling in Nevada City, California, the matriarch's hometown and a historic mining community. The firm's material-driven approach channels the pioneer spirit of the gold rush, without compromising comfort or high-efficiency standards.

Simpatico Homes founder Seth Krubiner has lived in the prefab company’s nearly net-zero prototype since it was customized and lifted onsite in 2011.

Components for low-cost prefab homes designed by Habitat for Humanity and the firm Minarc for South Central Los Angeles were trucked in and assembled over three days. Photos by Art Gray.

"The design for the Hanwha HQ media facade aims to avoid an overstated impact," says UNStudio founder Ben Van Berkel. "In the evenings, as the mass of the building becomes less apparent, the facade lighting integrates with the night sky, displaying gently shifting constellations of light."

A detail of the towers' facade.

Rice surfs the net at the built-in desk.

Most impressive of all, a solar array on the roof empowers the residents to produce more energy than they consume on-site.

UNStudio's proposal for the Hanwha headquarters in Seoul features a responsive facade that will be used to control the indoor climate during the day, and come alive as a dynamic light show during the night.

Big Man on Campus Built on Kolon Engineering and Construction's grounds, the E+ Home is the neighborhood's green building star. From this angle you can see the permeable pavers and sustainable landscaping, like water catchment pools and living walls, that make this place a paragon of green housing.

Photovoltaic Cells, of which Hanwha is one of the world’s largest producers, are built into the facade where they can receive optimal energy and harvest the most solar energy possible.

In place of the previous opaque panelling and dark glass, UNStudio will install insulated glass and aluminum framing to increase the amount of natural light and reduce overall energy consumption.

Roofreader Though they may look like architecture school run amok, the steep pitches and cants of the roof have everything to do with the home’s ecological agenda. By creating a series of green roofs, maximizing daylighting and water catchment, and optimizing the positions of light tubes and building-integrated photovoltaic panels, the roof is a canny mix of passive solar design and state-of-the-art technology.

A view of the installation at the House for Contemporary Art in Belgium.

Numen's Net, occupied by gallery attendees.

The E+ Green Home, a concept house located an hour outside Seoul, not only points the way to a greener South Korea, it may well be the most sustainable house in the country. Read more: dwell.com/slideshows/...

Four Box House perches on a rugged mountain-side in northern Seoul’s Pyeongchandong district, making for spectacular views.

At a net-zero home in San Francisco, the house's green roof is more of a brown roof: a desert-like array of native and non-native succulents that require minimal irrigation. The soil area is maintained with motorcycle tires (including one from a Harley hog), which control erosion. Composting takes place here as well.

Metal shingles cut from scraps of sheet metal mix with new material as well as odds and ends, such as a road sign Baker bought at the Alameda Flea market. Baker designed stainless steel clips that allow any tile to be easily moved or replaced without the use of tools. Planter box panels add functionality to the facade and can be swapped out or relocated throughout the year.

Hailing from Seoul, Jeonghwa Seo studied at the Design Academy Eindhoven in the Netherlands.

Green machines The E+ Home uses 95 different green technologies. Here’s our guide.

Architect Minwook Choi’s 710-square-foot Seroro House rises from a tiny urban lot in Seoul that had long been neglected because of its challenging size.

Rather than a one-off custom piece, Baker designed the daybed as a prototype and worked with Ohio Design on its fabrication.

The Catch lamp is based on a butterfly net.

“These are homes that are truly sustainable—they don’t create any waste in fabrication, and there’s no waste onsite.” —Tryggvi Thorsteinsson, Minarc. Photos by Art Gray.

“There’s no drilling or chopping,” says Erla Dögg Ingjaldsdóttir, cofounder of Minarc. “It’s a very elegant way to build.” Photos by Art Gray.

Underneath it All By capturing and storing storm water and heat underground, the house saves even more energy.

NET was founded by renowned architect Alejandro Sticotti in 1990. The firm prefers to use South American hardwoods that, in addition to being durable, anchor their products in their Argentine origins. For instance, the Silla ska chair (seen here) is made from lenga, a patagonian wood that resembles American cherry. The satin black floor lamp is also from NET.

Bullitt Center (Seattle, Washington: 2013) Denis Hayes, chief executive of the Bullitt Foundation, said that if the Bullit Center, his organization’s ambitious experiment in creating a sustainable and “living” office building, is still the greenest space of its kind in a decade, it will have been a failure. That’s not bragging, that’s merely an insight into the scope and ambition of this revolutionary structure, a testing ground for water and energy self sufficiency (via rainwater collection, composting, and a large solar array) aiming to be a case study for radical change in how we build. Based on stats released on Earth Day in April, the building’s first anniversary, the structure is currently using 75 percent less energy than a similar structure and is on its way to a net zero energy certification. Photo by Benjamin Benschneider

The Material Container series also includes tables.

Architect TaeByoung Yim designed a compact residence in Seoul, Korea, with designated space for studying and entertaining.

Located on a sharply sloped site in Pyeongchang-dong, a suburb of Seoul, South Korea, this home designed by Hyo Man Kim of Iroje KHM Architecture unfolds like an origami flower. Inside, secluded outdoor spaces lend sunlit interiors and privacy to the two-family dwelling housed within its faceted, asymmetrical exterior.

Jeonghwa Seo's Material Container stool in brass.