Built to Code Building Envelop Versus Sustainability of High-Rise Building Performance

Global warming and climate change are major challenges facing the nation and the world. More than two thirds of the electric energy and one third of the total energy are used to heat, cool, and operate buildings, representing majority of all CO2 emissions. A reduction in building energy consumption will help to mitigate the energy security and climate change effects on buildings. The reduction in energy consumption is accomplished through the development of new technologies (for the building's envelope, mechanical, and lighting systems) that save energy and reduce CO2 emissions. However, an alternative approach is the use of passive systems that employ renewable energy sources. Passive systems avoid the need for heating or cooling through better design, construction, and operation. They utilize solar or wind energy to heat, cool, or light buildings. This study analyzes the sensitivity of energy demand ed to build to code building’s envelops. In other words, investigating whether building that meets the need of enveloping code can take advantage of the weather surrounding the building, in terms of cooling, or heating (comfort) the building as needed. Four high-rise office buildings (glazed curtain wall) with four different aspect ratios (1:1, 1:2, 1:3, and 1:4) are thermally analyzed in four climate zones: cool, temperate, arid, and tropical. The envelope of these high-rise buildings is modeled to meet International Energy Conservation Code (IECC) requirements, which references several American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) standards. As a result, the energy performance of high-rise office buildings is not sensitive to the passive solar gain as long as the exterior envelopes are built to IECC 2009 requirements, which does not allow the use of the ambient climate condition of the building to get comfort. This is not appropriate from the concept of sustainability of buildings as referred to above.