Regarding construction on terrace

Hi sir, Can you please help me on this class. Builder like to construct an unauthorised construction on top of 4 floor building. We are trying to stop him but with below clause he said I have rights to construct. ========================== Whereas rights of the Terrace of the said complex will always remain with the VENDOR and hereby agreed by the third party. Further, the third party will not have any rights and claims on Terrace. ===================== Permission to construction only for �Stilt + Four Upper Floors�.