This year’s top 10 sustainable designs selected by the American Institute of Architects include two houses and several commercial and institutional buildings: a student apartment complex, a school expansion, and 67,000-sq. ft. inner-city warehouse redevelopment project.

The AIA’s Committee on the Environment (COTE) recognized this year’s winners at the organization’s annual convention, which was held from June 20 to 22 in Denver. (The winners were originally announced on Earth Day in April.)

The AIA declared that the competition “recognizes projects that successfully integrate exemplary aesthetics, advanced performance, community connection, social responsibility and stewardship of the natural environment.”

Most of the projects are large public buildings. The Federal Center South Building 1202, for example, is a $65 million, 209,000-sq. ft. regional headquarters for the U.S. Army Corps of Engineers in Seattle. But the list also includes two residential projects: a private home in Venice, California, and a new version of a house originally designed as part of a model community in Norris, Tennessee in the 1930s.

A new New Deal house

The “New Norris House” was designed to mark the 75th anniversary of a model community originally built in 1933 by the Tennessee Valley Authority as part of the Norris Dam construction project. The house is a team project of the University of Tennessee College of Architecture & Design.

It’s small (just 1,008 sq. ft.) and relatively inexpensive ($180,000), and it sits on a tiny lot (one-third of an acre).

According to its designers, the modeled energy use for the house is 7,123 kWh of electricity per year, less than half of the average energy use of homes in the region. It uses no fossil fuels and has a HERS rating of 49.

The house is heated and cooled with a three-head ductless minisplit heat pump. Mechanicals also include an energy-recovery ventilator and a solar hot-water system that preheats water for a tankless electric water heater.

The house was built off-site in two sections. The designers said that advanced framing techniques reduced lumber consumption by more than 17%, and that off-site prefabrication reduced construction waste by 70%.

Other features of the New Norris House include:

• A ventilated rainscreen.
• Wall insulation that includes R-21 batts and 1 in. of rigid polyisocyanurate.
• Salvaged white oak flooring.
• Low- and no-VOC glues, paints, and finishes.
• A flexible first-floor design that can be configured as open space, a one-bedroom space, or a two-bedroom space.
• Universal design that includes a ramped entry.
• Versatile pieces of furniture that can be deployed in more than one way.

There were 500 Norris houses built between 1932 and 1934, most of which are still standing, according to designers of the New Norris House. “The scale, character and durability of the houses and town’s walkability (especially for seniors and schoolchildren) provide enduring lessons. The New Norris House leverages and enhances these characteristics.”

In California, a home for a family

The other residential project that was honored this year is entirely different. It’s nearly four times the size, at 3,800-sq. ft., and cost almost ten times as much to build ($1.7 million). And it’s in the affluent California beachfront community of Venice.

Brooks + Scarpa submitted the design, which is called Yin Yang House. “Part private home and part business, the house is meant to serve as a place to entertain and a welcoming space for clients and teenagers,” the designers said. The owners remain anonymous.

The project was described as a “nearly net-zero” project with a very tight building envelope and a 12-kW photovoltaic array.

Designers said the house is organized around a series of courtyards. The building is one room deep to make the most of natural light and ventilation. The living room, designed for entertaining, includes — wait for it — a 50-ft. long sliding glass door.

The designers said that a variety of features contribute to the home’s low energy consumption. The house exceeds the requirements of California’s Title 24 energy code by 42%, while its energy use intensity (EUI) was 94% lower than that of a typical single-family home. The house has a HERS rating of 62.

Other building features include:

• Interior materials selected for high recycled content and low chemical emissions.
• FSC-certified wood for cabinets and flooring.
• Blown-in cellulose insulation.
• Low-flow water fixtures and dual-flush toilets, plus a system to capture and filter rainwater before it’s returned to the ground.
• Incorporation of an existing 1,200-sq.-ft. “tear down” in the renovated and enlarged structure, more than tripling the size of the original house with a net increase in lot coverage of less than 800 sq. ft.
• Drought-tolerant plantings and permeable ground coverings, along with a green roof and an artificial lawn that requires no water.