Role of daylight in preserving identities in heritage context

The narrow alleys and the small neighbourhood squares are the most recognisable urban configuration forms that highlight the fabrics of Old Cairo. Parts of Old Cairo are currently going through major conservation projects. The extent of the success of some of these projects in preserving the identity of the Cairene context is currently under scrutiny and has created a debate among local residents, professionals, and politicians. Preliminary investigation has been conducted to assess the rehabilitation strategy of the selected case of el-Darb el-Asfar in relation to its context. Daylight is an essential contextual ingredient that characterises particular places from its counterparts. The rehabilitation project, using new finishing materials, has led to changes in daylight levels and reflections in the space and hence modify the visual perception and the identity of the place itself. This paper aims to assess the impact of the proposed intervention on the visual perception and the identity of the selected built heritage. Daylight variables in open spaces, a combination of sunlight, skylight and the reflected light from the facades and the ground, are identified. Using TOWNSCOPE, daylight's components are calculated pre and after the implementation of the project. The performance of reflected component is traced by simulating the impact of the original and recently used materials. The paper concludes by suggesting a set of measures to achieve an appropriate daylight performance to achieve a sustainable development in the area and maintain the identity of the old city.

Urban heat island and wind flow characteristics of a tropical city

 Urban Heat Island (UHI) has become a growing concern to the quality of densely built urban environments, particularly in tropical cities. Wind speed has widely been reported to have decreased the intensity of heat island effect in urban areas. The cooling effect of the wind helps to mitigate the adverse effects of heat island on the micro climate and human thermal comfort. This paper investigates the existence of heat island in Muar, one of the fast growing cities in southern part of Malaysia and its possible causes, and then examines the effects of different urban geometry on the wind flow. The results of this study indicate that the chaotic development in Muar has caused reduced ventilation in urban canyons. The heat island intensity in the city center was recorded as 4. °C during the day and 3.2. °C during the night. Investigation of various urban geometry modifications showed that step up configuration was the most effective geometry as it can distribute the wind evenly allowing the wind to reach even the leeward side of each building. © 2014 Elsevier Ltd.