Abstract Compact city is one of the main constructs created in support of sustainable cities around the world. It helps to decrease urban sprawl and protect green and agricultural lands while reducing the demand on transportation. Compactness is foreseen to create urban microclimates that help reduce energy consumption in buildings. The objective of the current research is to investigate the effect of light-wells in urban buildings as a sustainable solution in compact cities that seek energy saving strategies. The proliferation of multi-storey apartment buildings in Jordan makes it difficult to provide interior spaces with the required amount of light depending on direct connection with the outdoor environment. Therefore, daylighting is highly required in core spaces. The research focused on introducing and developing the light-well as a daylighting device to significantly convey daylight to core areas in multi-storey residential buildings in semi-arid environments. The new device will help to transport the daylight over long distances, especially to lower floors, by collecting daylight and transporting it to inner spaces. The research used computer simulation to study many light-well variables to optimize its performance and compare them to a base case light-well. Simulation results have shown that the appropriate design of a light-well's opening could increase daylight performance while offering a reasonable trade-off between the light-well's cross section area and the building's height. The results showed that the best scenario for providing better illuminance levels in lower spaces in a four-flour building is having a light-well with a staggered vertical section and a vertical collection unit.