Our house is about to be renovated, and the property requires them to be porters, gravel, doors and windows, and security window. Is this legal?

This is illegal. Many communities sell this kind of cut. If you want to do it yourself, it will bring you all kinds of troubles. This one doesn't meet the requirements, and which one doesn't. Some properties are too strong for you, or under private communication, some properties will not let you, which is the hidden rule now.