To verify the accuracy of lighting simulation programs, the International Commission on Illumination (CIE) published technical report CIE 171:2006—Test Cases to Assess the Accuracy of Lighting Computer Programs, which can be applied to validate lighting simulation tools. This article reports the performance of DIALux 4.12 and DIALux evo 4.1 against the analytical test cases of CIE 171:2006. Both programs show very good agreement with the reference values in cases with point source. DIALux 4.12 yields noticeable errors at receiving points with small configuration factors, in cases with area source. Both programs show good agreement with the reference values in cases with diffuse reflection, respect luminous flux conservation, but do not respect variation in relative angular transmission due to varying incidence angles. Inaccuracies are found in daylighting scenes, particularly in the calculation of sky and externally reflected components. It may be of common interest for the CIE to amend the current document and publish a new version with possibly a new series of test cases.

Optimisation of shading devices in buildings is a broadly investigated topic; however, most studies only focus on a single façade orientation, since the observed buildings are typically located in high latitude regions. However, in tropical regions, optimisation of all façade orientations is required due to the relatively high solar radiation and long sunshine duration. While adaptive shading devices are a promising solution, they are not without disadvantages, and as such a combination of adaptive shading devices and a fixed shading device shall be considered. This research therefore aims to design the optimum internal shading devices on four façade orientations of a high-rise office building in a tropical city, considering fixed and adaptive shading design options, and to determine the impact on annual daylight performance using computational modelling and simulation. The simulation is carried out under: (1) fixed design option, focusing on the numbers and width of slats; and (2) adaptive design option, focusing on the slat angle on various conditions. It is found that both sDA_300/50% and ASE_1000,250 are only influenced by the orientation. Under the fixed design option, the sDA_300/50% and ASE_1000,250 targets can be achieved only on the north and south façades, and accordingly the adaptive design option shall be implemented on the east and west façades. Overall, this study contributes to knowledge regarding the optimisation of shading devices in high-rise buildings in the tropics, considering the daylight admission from the four cardinal orientations.