Architect Adrian Smith dropped a bombshell at the Council on Tall Buildings conference in Shanghai. The most sustainable type of residential construction, if all other things are equal, is not a tall building but rather a four-story walk-up community, he said at a press conference. His statement is based on his firm's ongoing research regarding carbon emissions associated with different residential building typologies in Chicago.
His firm studied 2,000 residential units in different configurations on a 500-acre site--from one tall building to a group of single family houses , each on a 1/4-acre site, and everything between. "The four-story wallk-up community is the most sustainable neighborhood from a carbon emissions standpoint," he said. "Supertall is inherently not as sustainable even if you plant prairie grass on the rest of the site. This was a surprise to us."
Smith continued by saying: "If we are going to continue to do supertall buildings, we need to produce power to be sustainable, not just reduce energy usage to drive down carbon emissions."  There are things that can be done to make them more sustainable, he stressed.
Most of the other speakers at the conference are lauding the sustainability of tall, in terms of density and urbanization. An irony is that Smith is the architect of the world's tallest building, the Burj Khalifa, and the future tallest, the planned 1-km-plus Kingdom Tower, in Saudi Arabia. He is also committed to sustainable design, which is what drove him to do the research. More conclusions when the research, called the Density Study, is finished. A book is expected in six months. It will take 250 pages to explain the findings, says Smith.