Built on a legacy of thousands of years of gradual innovation in construction technology and scientific advancement, architectural engineers apply the latest scientific knowledge and technologies to the design of buildings. For those of us living in the United States, we spend on average 70 of our 79 years of life inside of buildings. The structural safety and reliability of these buildings and the quality of the air we breathe inside of them are designed by architectural engineers. Since 40% of all energy in the U.S. is consumed by buildings, the energy that we can conserve and the construction technologies required to build sustainable cities are important issues that architectural engineers are skilled in. Working closely with architects and construction teams, architectural engineers enable the making of our everyday buildings as well as our monumental buildings. From reduction of greenhouse gas emissions to the construction of resilient buildings, architectural engineers are at the forefront of addressing several major challenges of the 21st century.