Green architecture, or green design, is an approach to building that minimizes harmful effects on human health and the environment. The "green" architect or designer attempts to safeguard air, water, and earth by choosing eco-friendly building materials and construction practices. When building a green home one chooses to do so to reduce the harmful impact on the environment. Careful thought and consideration must be placed on every aspect of this home design, from the roof to the foundation to everything in between - electrical work, air quality, and affordability. It is important to lessen one's footprint and not to disrupt the existing ecosystem. With all the knowledge and resources available to us today there really is no excuse for not being environmentally conscientious. Sustainable architecture is architecture that seeks to minimize the negative environmental impact of buildings by efficiency and moderation in the use of materials, energy, and development space and the ecosystem at large. Sustainable architecture uses a conscious approach to energy and ecological conservation in the design of the built environment. The idea of sustainability, or ecological design, is to ensure that our actions and decisions today do not inhibit the opportunities of future generations. Energy efficiency over the entire life cycle of a building is the most important goal of sustainable architecture. Architects use many different passive and active techniques to reduce the energy needs of buildings and increase their ability to capture or generate their own energy. One of the keys to exploit local environmental resources and influence energy-related factors such as daylight, solar heat gains and ventilation is the use of site analysis. Eco Home is an environmentally low-impact home designed and built using materials and technology that reduces its carbon footprint and lowers its energy needs. This includes: Glass that has two or three layers with a vacuum in between to prevent heat loss. Solar panels or wind turbines. Geothermal heating and growing plants on the roof to regulate temperature, quieten the house, and to produce oxygen. A Vegetable patch outside the house for some foodThe concept of an eco home means a dwelling that has a low impact on the environment. Sustainable building refers to both a structure and the using of processes that are environmentally responsible and resource-efficient throughout a building's life-cycle: from siting to design, construction, operation, maintenance, renovation, and demolition.  In other words, green building design involves finding the balance between homebuilding and the sustainable environment. This requires close cooperation of the design team, the architects, the engineers, and the client at all project stages.  The Green Building practice expands and complements the classical building design concerns of economy, utility, durability, and comfort. A similar concept is natural building, which is usually on a smaller scale and tends to focus on the use of natural materials that are available locally.  Other related topics include sustainable design and green architecture. Sustainability may be defined as meeting the needs of present generations without compromising the ability of future generations to meet their needs.  Although some green building programs don't address the issue of the retrofitting existing homes, others do, especially through public schemes for energy efficient refurbishment. Green construction principles can easily be applied to retrofit work as well as new construction.