A method and device for improving natural lighting within buildings is provided. The device comprises a controllable shelf having an upper, specular reflective surface for directing natural light into interior spaces and against interior ceilings. The shelves can be static or pivotable to redirect light based on the day and time of year. The pivotable shelf can be rotated downward or upwards to change the angle with which the light is reflected into the adjacent window, while its position is below the window and along the exterior of the building. This improves interior natural lighting and reduces electrical lighting costs using either a static shelf or movable shelf, wherein the assembly is deployable in a commercial or residential environment without blocking any naturally entering light through the window itself.