A balcony is a great feature, but you have to check the drain or drains every so often. A large balcony will generally mean a large roof and that has the potential to cause problems when a downpour occurs. Some of my neighbors have a balcony in front and several have water stains on the garage ceiling below the balcony. When you consider that the huge roof dumps onto the balcony below, you can understand how important it is to keep the drains clear.
Certainly, it makes sense to give a thorough inspection to other potential problems as well. When it rains heavily, look out at the balcony deck. There is probably a primary drain and a secondary drain in case the water starts rising quickly. You might have just cleared the balcony of all debris, but when it rains heavily, the rain will wash the debris on your room down onto the balcony, which can clog the drains. It is a good idea to be vigilant when it really starts coming down. In some cases the drains will clog and will get high enough to enter the house from under the door. Take a look at the picture, there isn’t any large piece of debris there. It is just lots of small leaves that slow the draining water enough to allow a back up.