Is it illegal to build a patio with a sun shed?

If it is an old-fashioned residential area, it can generally be built. As long as there is no objection above the second floor, the property is fine. If it is a commercial house, there are provisions in the purchase contract agreement between the owner and the developer, such as no balcony, no sun shed in the patio, no hanging clothes rack, no flower stand and so on. It is illegal to do it. But there are often too many people and the property can't be managed.