Global and urban-induced local warming lead to increasing heat risk in cities. The rapid increase in urban population, weak infrastructure, poverty, as well as an ageing population, make the risk more acute in developing cities. However, heat risk is not uniformly distributed and a detailed exploration of the link between urban characteristics and local variations in heat risk is needed to aid targeted mitigation. In this paper, we demonstrate a fine-grained heat risk map using existing data combined with expert opinion in a humid tropical city (Colombo, Sri Lanka) with the objective of highlighting the relative heat risk as a function of physical and socioeconomic conditions across the city. We then simulate the effects of shading and greening on the ‘high’ heat risk areas, and greening on the ‘low’ heat risk areas, to show that a combined approach will be needed to reduce risk at ‘high’ risk areas. In ‘low’ risk areas, maintaining the green cover is crucial to heat risk reduction. The paper, thus, establishes a protocol for detailed heat risk mapping with existing data and points to the differing importance of shading and greening in different parts of the city, thus, showing where, and to what extent, mitigation actions could be beneficial.

Architectural lighting is now simple and emotionless due to modern technological innovations, which makes it difficult to recognise the distinct character of a place. With the development of air conditioning and artificial lighting systems, architects are more inclined to adopt them than to design equivalent spaces in natural light, thus, taking advantage of ideal lighting conditions to raise the quality of space. The major difference between artificial light and daylight is the “view”, daylight integration systems offer. This is a research initiative to ascertain the perceptual influence of daylight and ‘window view quality’ in achieving visual comfort. With this in mind, a single case study is investigated, thereby involving like-minded respondents that engage in a similar work programme. As a limitation of scope, an environmentally rated building in a specific locality – Jaffna – is selected. Post Occupancy Evaluation forms the primary method adopted. Mapping of the space is undertaken, together with Perceptual Spatial Analysis (PERCIFAL) surveys, and correlate responses to the physically observed spaces. Results show the occupants agree that natural light is the preferred mode of lighting for the workspace. Although the window views are deemed to enrich the working environment, the emphasis on its preference does not strongly correlate among all respondents. Conclusions are drawn on the parameters surveyed - that drive window view quality and daylight perception - to form implications for design both as individual elements and as a whole, to achieve overall visual comfort within a specific office environment.

Colombo, with its rapid development, is experiencing an influx of high-rise developments. These developments create a significant influence on the microclimate of the area around them, and therefore impact outdoor thermal comfort. With the intension of mitigating outdoor thermal comfort concerns, the enhancement of the vegetation cover is an often-proposed strategy. This is a research initiative to ascertain the optimum vegetation cover percentage to achieve outdoor thermal comfort around high-rise developments, utilising Havelock City, Colombo, Sri Lanka as a case study. A computer simulation process is adopted, using the software ENVI-met, to explore the optimum form and coverage of vegetation for outdoor thermal comfort. Results show, overall thermal comfort levels diminish, with the increased infusion of vegetation. Vegetation cover had a little or no impact in the daytime, while the strategy had distinct negative impacts in the night-time. The nature of the built morphology of the development together with the vegetation cover increase is shown to have significant impact on wind movement and nocturnal heat loss, therefore outdoor thermal comfort levels. Conclusions highlight the need for the extensive exploration of morphological studies, while encompassing key amelioration strategies, particularly for the high-rise development typology.