The daylighting performance improvement of manual solar shades was compared with two conventional window scenarios. A developed stochastic model for manual solar shades was used for co-simulation by BCVTB. Results show that manual solar shades increase useful daylight illuminance by approximately 160 % compared to conventional windows with less significant daylight illuminance fluctuation. In addition, occupants operate solar shades effectively during the late spring and early summer and the manual control during other periods can be further improved to enhance daylighting performance.