By the mid-1980s and continuing through the ’90s, the number of environmental advocacy societies radically expanded; groups such as Greenpeace, Environmental Action, the Sierra Club, Friends of the Earth, and the Nature Conservancy all experienced burgeoning memberships. For architects and builders a significant milestone was the formulation in 1994 of Leadership in Energy and Environmental Design (LEED) standards, established and administered by the U.S. Green Building Council. These standards provided measurable criteria for the design and construction of environmentally responsible buildings. The basic qualifications are as follows:

1. Sustainable site development involves, whenever possible, the reuse of existing buildings and the preservation of the surrounding environment. The incorporation of earth shelters, roof gardens, and extensive planting throughout and around buildings is encouraged.
2. Water is conserved by a variety of means including the cleaning and recycling of gray (previously used) water and the installation of building-by-building catchments for rainwater. Water usage and supplies are monitored.
3. Energy efficiency can be increased in a variety of ways, for example, by orienting buildings to take full advantage of seasonal changes in the sun’s position and by the use of diversified and regionally appropriate energy sources, which may—depending on geographic location—include solar, wind, geothermal, biomass, water, or natural gas.
4. The most desirable materials are those that are recycled or renewable and those that require the least energy to manufacture. They ideally are locally sourced and free from harmful chemicals. They are made of nonpolluting raw ingredients and are durable and recyclable.
5. Indoor environmental quality addresses the issues that influence how the individual feels in a space and involves such features as the sense of control over personal space, ventilation, temperature control, and the use of materials that do not emit toxic gases.

The 1980s and early ’90s brought a new surge of interest in the environmental movement and the rise to prominence of a group of more socially responsive and philosophically oriented green architects. The American architect Malcolm Wells opposed the legacy of architectural ostentation and aggressive assaults on the land in favour of the gentle impact of underground and earth-sheltered buildings—exemplified by his Brewster, Mass., house of 1980. The low impact, in both energy use and visual effect, of a structure that is surrounded by earth creates an almost invisible architecture and a green ideal. As Wells explained, this kind of underground building is “sunny, dry, and pleasant” and “offers huge fuel savings and a silent, green alternative to the asphalt society.”

The American physicist Amory Lovins and his wife, Hunter Lovins, founded the Rocky Mountain Institute in 1982 as a research centre for the study and promotion of the “whole system” approach favoured by McHarg and Lovelock. Years before the LEED standards were published, the institute, which was housed in a building that was both energy-efficient and aesthetically appealing, formulated the fundamental principle of authentic green architecture: to use the largest possible proportion of regional resources and materials. In contrast to the conventional, inefficient practice of drawing materials and energy from distant, centralized sources, the Lovins team followed the “soft energy path” for architecture—i.e., they drew from alternative energy sources.