I want to know, who is responsible for the problem of water seepage on the windowsill of the new house in rainy days? What should I do as an owner?

Go to the property management company for this problem. When you buy a house, you have already paid the house maintenance fee, so the problem is that you need the property to solve it for you.

Also, if you don't have a property, ask the developer. If you have a property, look for it, because there is a contract between the property and the developer. The developer entrusts the property to complete this problem.

I don't know if you understand, but there is something wrong with property management now. If you don't care, you can make trouble with him and let him go.

I wish you a happy life