Is it illegal for residential property management to deliberately prevent hydropower transformation in old residential areas?

It is not illegal for residential property management to deliberately prevent hydropower transformation in old residential areas.

It depends on where you want to change the water and electricity, because it is forbidden to change the water and electricity in the bathroom balcony, because it involves waterproof problems, and a slight change will affect the residents in the unit below your unit. Moreover, changing the toilet balcony can only be done by the original design unit or the construction unit with relevant qualifications. Except for the toilet balcony, other water and electricity can basically be changed.