Solar radiation-based method for early design stages to balance daylight and thermal comfort in office buildings

There is a lack of facade design methods for early design stages to balance thermal comfort and daylight provision that consider the obstruction angle as an independent variable without using modeling and simulations. This paper aims to develop easy-to use solar radiation-based prediction method for the design of office building facades (i.e., design parameters: room size, window-to-floor ratio, and glazing thermal/optical properties) located in urban canyons to balance daylight provision according to the European standard EN 17037:2018 and thermal comfort through specific cooling capacity. We used a simulation-based methodology that includes correlation analyses between building performance metrics and design parameters, the development of design workflows, accuracy analysis, and validation through the application of the workflows to a new development office building facades located in Tallinn, Estonia. The validation showed that the mean percentage of right/conservative predictions of thermal comfort classes is 98.8% whereas for daylight provision, it is higher than 75.6%. The use of the proposed prediction method can help designers to work more efficiently during early design stages and to obtain optimal performative solutions in much shorter time: window sizing in 73,152 room combinations in 80 s.