Is it illegal to enlarge the bedroom window?

Belonging to illegal construction or unauthorized construction. This is a violation of property management regulations, residential management regulations (in the case of a residential property) or housing use safety regulations.

Any building that is not within the scope of the building drawings is illegal, and there is a great security risk in expanding the balcony. Although the balcony expansion is very dangerous, as long as no one reports it, there will be no problem. Once found, it will be ordered to rectify, and the owner must restore the original wall structure.