It is haraam to build anything over graves

No File Exists
Check below answers in case you are looking for other related questions:
Reading Quran for a Deceased Person
How can he seek the forgiveness of one who has died?

No File Exists
Related Answers:
Muslim being washed and buried with the kuffaar
Exhorting the dying person to say Laa ilaaha ill-Allaah
Burying one who neglected prayer with the Muslims
Reading Quran for a Deceased Person
How can he seek the forgiveness of one who has died?

Recommended answers for you:
Reciting Surahs and Aayahs in a different order
Ruling on dealing in currencies in the FOREX system and paying fees for delaying the deal
Knowledge in Islam
She feels attracted to someone other than her husband
She did not eat suhoor and did not wake up for Fajr. Should she carry on fasting or break her fast?