A new color is catching on in construction: green.

Five years ago, green building was just a dream among passionate proponents who insisted that the practice would save money by using less energy and water, improve public health and lessen environmental impacts by better design, operation and maintenance.

Today, developers who predicted that green – sometimes called sustainable or high-performance – building was just a fad are launching projects that promise a new paradigm. Dozens of buildings that boast green features are in the pipeline, including the proposed 49-story office tower at South Station and Genzyme Corp.’s 177,000-square-foot science facility in Framingham.

Green building is the practice of creating healthier and more resource-efficient models of construction, renovation, operation, maintenance and demolition. The high-performance facilities promise to promote occupant health; improve employee productivity; use energy, waste and other resources more efficiently; and reduce the impact on the environment.

“A few years ago, no one ever heard of green,” said James Hunt, Boston’s chief of environmental and energy services. “But the word’s out and we’ve done lots of outreach to let the development community know that green building does not have to cost more.”

In January, Boston became one of the first U.S. cities to incorporate green building into its zoning regulations. At the request of Mayor Thomas M. Menino, the Green Building zoning provision, Article 37 in Boston’s zoning code, requires that projects over 50,000 square feet meet a basic level of certification based on the Leadership in Energy and Environmental Design (LEED) rating system.

Menino launched the Green Building Task Force in 2003, demonstrating a commitment to green building and smart growth. Comprised of experts in building design, construction, management and financing, as well as public health and environmental experts, the task force explored the opportunities and challenges of green building.

Among their findings: Green buildings not only decrease negative effects on the environment, they also can generate substantial cost savings for building owners and tenants, reduce dependency on imported energy and enhance worker health and productivity.

Hunt said it is essential for cities to require green construction because buildings rival automobiles as a cause of pollution. In Boston, buildings account for more than 50 percent of the air-quality impacts and greenhouse gas emissions, above the national average, according to Hunt. Nationally, 33 percent of pollution stems from automobiles, while 37 percent is emitted from buildings.

“This really is a quality of life and public health issue,” said Hunt. “If you consider that New Englanders spend 70 percent of the time indoors, green buildings are good for the environment, public health and the bottom line because it reduces the cost of operation and improves productivity in the workplace.”

Green advocates say that the practice of green building can lead to benefits like reduced operating costs by increasing worker productivity and using less energy and water. In addition, they argue that improved public and occupant health will result due to indoor air quality. Environmental impacts will be lessened, advocates say, by lessening storm water runoff.

Barbra Batshalom, an architect and executive director of the Green Building Resource Center in Boston, said she founded the group because she was frustrated by the high level of dysfunction in the construction industry.

“Every building that I worked on had mechanical systems that were twice as large as they needed to be, indoor air quality that wasn’t healthy and the high number of change orders were the direct result of a lack of integrated design,” she said. “One of the things that defines green is the design process, which gets the architect, general contractor and engineer working together early on.”

Batshalom, an architect who has designed homes, museums and aquariums, said the problems were the same in all types of projects. “I thought the process was ridiculous and decided to set aside time to meet and talk about how we could do better work,” she said.

She launched small-group lunch meetings across the city. Within a year, the sessions grew to 50 professionals who talked about construction and demolition, waste and facility management, air quality, mechanical systems, design and materials. Today, they meet at the Massachusetts Institute of Technology and Harvard University, or wherever they can find space.

‘No Excuse’

The Green Building Resource Center on Chauncy Street in Boston offers a number of free resources, including a showroom for green products, technologies and services, which includes a revolving exhibit series showcasing key issues in the green building field; a resource lounge with books, periodicals, technical manuals and sustainable design and construction reference materials; and a sample library with a collection of green product samples for building projects.

Earlier this year, Hines, an international real estate firm, along with co-developer TUDC, a subsidiary of Tufts University, declared that the proposed 621-foot tower to be built atop Boston’s South Station was the first office building in the city to be pre-certified based on the LEED system.

LEED is a nationally accepted benchmark for the design, construction and operation of high-performance green buildings. The rating provides building owners and operators the tools they need to have an immediate and measurable impact on their buildings’ performances.

LEED promotes a whole-building approach to sustainability by recognizing performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality.

The proposed one-million-square-foot South Station office tower was pre-certified at the Silver level based on the submission of documented plans to satisfy green performance and systems requirements.

Still, the biggest questions from builders concern the costs of building green. The jury is still out on how much it will cost a developer to incorporate green features and high-efficiency systems.

Experts say it is difficult to do an apples-to-apples cost comparison of a green structure compared to traditional construction. But many experts say that a green building might cost slightly more up front, but will likely reap the rewards of lower operating costs going forward.

A 2004 nationwide study conducted by the research and consulting firm Capital E found that structures that qualified for the lowest LEED rating cost builders less than 1 percent more up-front then equivalent non-green buildings. For projects with more ambitious green features that qualified for higher LEED ratings, the cost premiums went up from between 1.9 percent and 6.8 percent, the study said.

“Whatever your budget is, there’s no excuse for the building not to be green,” said Batshalom. “If you ever have a building professional tell you it can’t be green unless you pay more, they don’t know what they’re doing.”