Designing High Density Cities – Parametric Studies of Urban Morphologies and their Implied Environmental Performance

Abstract

Cities of tomorrow must embody the concept of sustainability. Urban design is not about drawing patterns on paper and its architectural studies could not be merely spatial, formal or geometrical. Urban design of the next millennium is about providing and optimising an infrastructure for the enjoyment of its inhabitants while at the same time minimising energy and resources needed, and maximising the benefits of the natural environment. An important consideration of urban design is to provide natural outdoor conditions that are pleasant to human activities. A well-designed outdoor urban environment will also make the design of individual buildings within it easier. Hong Kong and Singapore share common climatic and environmental conditions. Both are cities with limited land resources with a growing and more demanding population. Planning the cities to cope with needs is an important task for their planners. There are many design parameters, for example: Development Density, Plot ratio, Site Coverage, Skyline, Building to Space Ratio, Permeability, Building Shapes and so on. This chapter reports a study based on “skylight” as a design parameter, and how it affects daylight and natural ventilation performances. Experiments were conducted with physical models in wind tunnel and artificial sky, as well as using CFD and computational lighting simulation. The study establishes that, for example, by varying the skylines of the city, the overall daylight and natural ventilation performances could be improved when compared to a city with a uniform skyline. A key message of the chapter is that, through a better understanding, high density cities could be planned and optimised environmentally without losing the development efficacy of the land.