The report, produced by UNEP's Sustainable Buildings and Climate Initiative (SBCI), a think tank and partnership between the United Nations and leading companies and organizations in the building sector, presents results from almost three years of research and collaboration with leading experts around the world.

Buildings contribute to well over one third of global energy use and associated greenhouse gas emissions, but also have a huge potential to achieve drastic emission reductions at virtually no cost. For example, landmark structures such as New York City's Empire State Building, at 102 stories and 242,000 square meters, is set to reduce its current emissions by 38 percent by 2013 through a US$20 million retrofit, resulting in annual savings of US$4.4 million.

According to the report, the current climate footprint from buildings is equivalent to 8.6 billion tons of CO2 a year and is predicted to almost double to 15.6 billion tons of CO2 by 2030. In addition, the pressure to develop new buildings - as a result of population growth, urbanization and modernization - will lead to an almost doubling of existing building stock in developing countries by 2050.

The report highlights the opportunity lying within buildings to deliver cuts in greenhouse gas emissions through proven policies, technologies and knowledge that already exist to deliver the cuts needed.