Much of the best thinking about green building practices comes from the U.S. Green Building Council, a non-profit group of architects, developers and other concerned building professionals formed in 1998 to reform design and construction methods for a more sustainable environment.  The touchstones of USGBC’s approach include:

• Striving for design and construction approaches that have as little impact on the environment as possible
• Slowing the growth of energy demand as a result of construction, reducing energy demand where possible and adapting alternative energy sources when possible and practical
• Conserving water resources
• Reducing water and air pollution
• Reducing the solid waste stream
• Selecting building products and designing for safe, healthy and accessible buildings
• Building durable buildings that are adaptable for new uses during their lifecycle

• Sustainable Sites
• Water Efficiency
• Energy & Atmosphere
• Materials & Resources
• Indoor Environmental Quality
• Innovation in Design

LEED Guidelines for Remodeling
Increasingly applied in new commercial and residential construction, LEED has not yet developed a comprehensive point rating system for home remodeling. Home remodeling projects cannot be certified. Instead, LEED has established the Regreen Program, which is a set of resources and tools that provide guidelines for environment-conscious remodelers.

• A kitchen remodeling project in which the challenge is to accommodate all of the desired functions of a modern kitchen with enlarging the space. The green approach also addresses opportunities to install energy-efficient lighting and appliances, water- and energy-efficient plumbing fixtures and faucets, ventilation to promote healthy indoor air quality, elimination of electrical hazards, universal design that facilitates aging-in-place and reduces the need for further remodeling during the owners’ later years, and selection of resource-friendly, low-emission cabinet materials.
   
• A bath remodeling project that addresses water management in supply and drain lines with high-performance faucets, shortening the distance between the water heater and points of use to reduce waiting time and save energy and a gray-water system for outdoor irrigation that conserves water and cuts flow of contaminated waste water into the public water system. The project also makes priorities of exhausting of water vapor and selecting durable structural and finish materials for walls and floors to prevent growth of unhealthy, destructive mold, mildew and rot.
   
• A bedroom remodeling project that illustrates approaches for creating a healthy, restful indoor environment free from hazards such as electromagnetic fields; effective ventilation is one of the engineering focuses.
      
•  Reconfiguration of living and working spaces to improve function and flow without enlarging the home.
   
• A basement remodeling project that in addition to providing new, functional living space addresses typical issues of moisture control, radon mitigation, indoor air quality, lack of natural light, insulation and energy efficiency.
   
• A home performance upgrade that improves energy efficiency and indoor air quality with intensive modification of the building. The case study focuses on pre-design assessments , including energy testing, combustion safety, insulation, air sealing, HVAC equipment and ducts, moisture and lighting.
   
• A major addition that assesses the how much extra space is actually needed and evaluates three options including enlarging the footprint of the home, tucking an extra floor under the existing cap and adding an additional story. The case also evaluates options to find the most green foundation system for the addition: full basement, ventilated or unventilated crawlspace, piers or slab-on-grade. The salient issue is how to create the needed additional living space while limiting new space that must be heated and cooled to a minimum.
   
• A gut-rehab project that illustrates the design process for integrating what’s good about the existing building with 21^st-century standards. The case study considers whether gut-rehab is the favorable approach over deconstruction and rebuilding of the home, best practices for insuring the integrity of the building envelope, salvaging materials to reduce waste, remediation of hazardous materials present and the possibilities for replacing central heating and cooling with “task” appliances that operate in certain locations only where and when they’re needed.
   
•  A deep energy retrofit that succeeds in reducing all energy loads in the home by 50 to 90 percent, including those for heating and cooling, hot water, lighting, appliances, and general circuits. The case also studies relationships among indoor air quality, thermal comfort, energy use and durability.
   
• An outdoor project that expands the home’s living area with increasing its square footage. Other benefits of the case’s green approach include improving site drainage, reduced water consumption through judicious plant selection, and greater comfort through improved natural shading and alteration of wind patterns.