Public Interest petition is filed under Article 226 of the Constitution, and hence generally it can filed against public authorities only. The builder is a private person, hence in general he is not amenable to this petition.
What you are saying is a violation of building law- which should be tackeled as per the ordinary law. Look into the ordinary building laws applicable there, and you will find provision where a person can make complaint to the authorities, or even to courts. In any case, for public nuisance criminal compaliant can be filed.
If however, despite your complaint to municipality, no action is taken by them- you can file a petition against them. Before approaching the High Court under Article 226, all other remedies ahould be exhausted. In fact many a times, a pending petition in High Court becomes a excuse for public authorities not to take any action saying that issue is pending in High Court.