Nigeria is among one of the development countries that growing rapidly in all sectors which include the sector in construction. Nevertheless, some of the new buildings are poorly constructed. One of the components that need attention is the defects in new buildings. The aim of this study is to evaluate the causes of defects and the objectives of this study are to determine the causes of defects in new buildings, to determine the types of defects in new buildings and to determine the solutions of defects in new buildings. A qualitative research was conducted by interviewing nine interviewees who have experienced in high-rise residential buildings. The results are analyzed by interpretation. According to the study, the causes of defects in new buildings are poor workmanship, work executed are not in proper manner, poor material usage and not according to specification, lack of supervision, surrounding temperature and environment, limited time, manpower allocation and not follow the method statement given. The types of defects are structural cracks like wall cracks, hairline cracks at joint of beams and columns, architectural cracks like plastering fall off and peeling paint, honeycomb, pipe clogged and cause leakage at toilet, roof leakage, hollowness at columns and floor tiles. The solutions to overcome the defects in new buildings are engage third party or an expert, revise back the method statement, ensure good workmanship, have a rehearsal before doing anything, give proper training to workers and ensure good quality of materials before usage. A conclusion was made and recommendations are included for future studies.