There is an important difference between green interior design (often called 'sustainable design') and interior design. Whereas interior design is based primarily on changing ideas about 'good taste', 'elegance', 'function' and 'style', green interior design is primarily concerned with the permanent values of saving energy, conserving water, making indoor air healthy, reducing carbon emissions and carefully using natural resources. These are ideas that are not affected by magazine editorials and TV make-over shows. Interior design is about aesthetics – about looks. Green interior design, while it obviously seeks to design spaces people find pleasing, is focused on ethics – about what is good for the environment, good for saving money and good for people's health. It is within this paradigm of 'people, money and environment' that a green interior designer works.

The US Green Building Council (USGBC) formed the Leadership in Energy and Environmental Design (LEED) program in 1998 to form a set of standards for construction companies, local governments and interior designers to 'green up' buildings and offices. The founding principles were to promote buildings that are more energy efficient, less carbon intensive and healthier for people to live in. The idea was to promote energy efficiency to not only reduce carbon emissions but to encourage companies to turn to green building practices out of a financial motive. In the short term, installing energy saving technology can be expensive, but in the long term this technology will save money for a company.

There are many ways to promote energy efficiency through green interior design. One is to consider heating and cooling costs. To reduce heating costs in the winter houses should be correctly insulated and energy efficient space heaters should be deployed in key living areas. To cut down on cooling costs in the summer awnings should be put on south facing windows and blinds or curtains should be used to further reduce thermal gain. For east facing windows planting trees outside is a good idea to create natural shade. Open windows, use a ceiling fan instead of an air-conditioner unit to cut down on summer cooling costs. Also for year round energy savings install a new programmable thermostat that automatically turns the heating/cooling system off during the day when you are out and turns down the heating/cooling when you are sleeping. Finally, if you must use an air-conditioner install one with an Energy Star rating. All these measures are good examples of green interior design that will reduce carbon emissions (by reducing electricity used) and reduce your energy bills.

Another key concern of green interior design is indoor air quality. Many household and office products contain a variety of volatile organic compounds (VOCs) such as formaldehyde, benzene, methylene-chloride, toluene and acetone that cause respiratory problems, early puberty, cancer, pregnancy complications, allergic reactions, ground water pollution and smog. These VOCs are commonly found in paints, paint thinners, nail polish, furniture and flooring glue, marker pens, copier ink, carpet backings and a host of other products. A green interior designer will look to take an inventory of household products containing VOCs and look to replace these products with low-VOC or VOC free alternatives. For furniture a green interior designer will choose pieces made with water based adhesives or recommend using antique furniture. Antique furniture has lost all its toxicity because the VOCs have long since 'off-gassed'.

The choice of materials used for flooring, furniture and soft furnishings is another key part of green interior design. Recycled materials such as reclaimed hardwood flooring are preferred to new materials. Natural materials such as wool carpets and organic cotton sheets are less carbon intensive and better for the environment then synthetic materials derived from petro-chemical products. And using quickly renewing resources such as bamboo, rattan, coconut, jute and cork are preferred to slowly renewing resources such as hardwoods.

From these brief examples of how a green interior designer thinks it is clear that although the designer will want to make a comfortable, stylish and functional living area for his or her client the main concern is about being environmentally friendly, saving money and reducing carbon emissions.