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This paper examines the effect of building shape, zones, orientation and window to wall ratio (WWR) on the lighting energy requirement and the thermal comfort in the naturally ventilated houses in tropical climate. The lighting electricity and the adaptive thermal discomfort hours (ASHRAE 55 80% acceptability) of 300 different models of two-storey houses were obtained using Design Builder simulation software. The models were developed for three building shapes (square, rectangle and L-shaped) and the orientation of each model was changed for 24 orientations and four window to wall ratios. Results indicate that the rectangular shape with staircase positioned in the middle of the house will provide higher thermal comfort for WWR of 20 and for other WWRs the L-shaped models provide higher thermal comfort when the staircase is positioned at the short corner or middle. The square-shaped houses with staircase at the middle have the highest lighting electricity and the L shape has the lowest lighting electricity. Further, WWR changes the thermal comfort by 20-55% and the percentage change in lighting electricity due to WWR is only 1.5-9.5%. Therefore, thermal comfort should receive more attention in deciding the WWR. Moreover, the results show an effect when the zone sizes and location change.

One of the most important problems in the construction industry is variations. They occur in every construction project and the magnitude of these variations varies considerably from project to project. Hence, the variations orders bear great importance right from the inception to completion in the construction industry. Most of the road construction projects in Sri Lanka have experienced a large number of variation orders. The client had to spend more than what was initially estimated in most cases. Sometimes, disputes and unnecessary delays occur due to variations. This study attempted to reveal the possible causes of variation orders in the road construction projects in Sri Lanka. The data were collected through a literature review, a case study analysis focused on 11 road construction projects, and a questionnaire administered to professionals in the road construction industry in Sri Lanka. The study found out that the causes in the local context differ from those in the international context. According to the questionnaire survey, poor estimation was the most significant cause of variation orders. Unforeseen site conditions, political pressure during construction stage, poor investigation, and client-initiated variations occupy the 2nd to 5th places, respectively, in the ranking. This ranking was further proven through the case study analysis.

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