Computing Energy Performance of Building Density, Shape and Typology in Urban Context: Fid-Bau Portal

Computing Energy Performance of Building Density, Shape and Typology in Urban Context

Quan, Steven-Jige / Economou, Athanassions / Grasl, Thomas / Yang, Perry-Pei-Ju

This paper aims to better understand the impact of urban context on building energy consumption. The factors of external shading, shapes generated from zoning ordinances, and local climate are examined concerning three main questions: (1) how density influences building energy consumption generally, (2) how a given density generates alternative building shapes that have different impacts on energy performance, and (3) how different typologies affect the energy-density relationship. To answer them, a series of parametric simulation experiments are conducted based on Martin and March's urban block structure. For more than 14,000 hypothetical models located at the Portland urban grid, the energy consumptions for the purposes of cooling and heating are simulated using AutoCAD script, MATLAB and Energy Plus 8. The results suggest that, different from the common perceptions, building energy consumptions for cooling and heating purposes do not always have a negative relationship with density. Instead, the energy consumption has a negative relationship with density before a turning point, and then the relationship changes to be positive. Also with the same FAR, different building cover ratio and typologies can lead to large variations in energy consumption. By the experiments on different building shapes generated by urban frit, it was found that even with the same typology, the building energy consumption can still vary significantly. Finally, the exploration of climate factors indicates that in both Portland and Atlanta, the findings are similar except that the energy-density relationship is weaker in Atlanta than in Portland.