Perscriptive method - Bay Depth to Core

The prescriptive method should not be used to determine whether you have good daylight or not. What if that space is north facing in a northern climate that has alot of overcast days? You may have to provide more glazing with a higher VLT to meet the daylight needs year round. Since the prescriptive method is a general formula, the formula is what it is. You can try and break up the space into multiple daylight zones, but that may make it worse. I would recommend simulation, there are some free downloads of daylight simulation programs such as SPOT that can help you. I would not change a design based on meeting the requirements of the prescriptive method.