There is no so-called standard size for balconies, which are all designed according to different huxing. General dimensions are 1.5× 1.5, 1.5× 1.8,1.8×1.8×/2.60. The size of the balcony is also different. If you want a sealed balcony, I suggest you choose environmentally-friendly and energy-saving materials and choose the sealed one.