Building Envelope




/* Style Definitions */
{mso-style-name:”Table Normal”;
mso-padding-alt:0in 5.4pt 0in 5.4pt;

In this article, I will introduce a building that stand as a great example of innovating methods in construction new building envelope and facades.  Al Bahr Towers are two twine high-rises located at the capital of the UAE. Consist of 25 floor each with a total area of 70,000 sq m and a height of 145m, they became the headquarter of the Dubai Investment council. As most of the high-rises in the world, AL Bahr Towers are covered with a glass façade which form the main envelope of the building. However, for a tall glass building in a location like UAE, where the average temperature in the summer surge to more than 40 degree Celsius, it would become unbearable to live or work in such a structure because it is subject to the green house effects.  Therefore, two options was facing the engineers either spends a lot of money on Air Conditioning systems (AC) or come up with a creative solution to solve this issue.

Building envelope or building façades is a field that is closely related to architectural engineering. Heat transfer, insulations, and thermal resistance are all topics that are related with architecture engineers. However, in high-rises such as Al Bahr Towers, engineers are constrained with the type of the materials and the thickness of the wall that they are allowed to be used because of the addition weight that it would exert of the structure and also for aesthetic reasons. As a result, the engineers and the architects in the Al Bahr Tower created a lattice screen that covers the glass façade according to the sun orientation. This lattice screen is inspired from the local traditional wooden screen that covers the windows in ancient Arabian housed as a method to prevent excessive amount of sun heat radiation from entering the building.  However, in order to control the amount of sun light entering the building, new technology was to used to create a moving sunshades that opens and closes according to the sun orientation and solar radiation.

The lattice screen was created thanks to the allocation and integration of advanced electric sensors with the moving parts of the lattice’s structure. The sensors and the moving electric components created a moving façade hat open and close in response to the sun, reducing heat gain by more than 50%. Using less air-conditioning helps reduce the towers’ carbon emissions by an estimated 1,750 tons per year, according to Times article of the best inventions of the year 2012. In addition, the façade in Al Bahar is connected by a computer-controlled system to optimize the solar and light conditions. As a result, this demonstrate how important and necessary to integrate structural envelope system with electrical system to optimize the function of the building envelope.

Al Bahr towers create a great example to understand the new innovations in building envelope and the external structural of a building. An architectural engineer, that understands the main principle of heat transfer and insulation with a solid understanding of shading and solar radiation, can create innovated building envelope and façade.