Institutional building should provide conducive environment that would enable staff and students perform optimally. This functional requirement is sustainable through maintenance. A cognizance survey through tertiary institutions in Owerri metropolis, revealed alarming rate of building defects. The research is aimed at evaluating these defects and their maintainability, with a view to recommending appropriate solutions for overall improvement. The objectives were to: determine the nature and extent of defects; concepts that are not in line with design for maintainability; mode of maintenance; limiting factors; and consequences of delayed maintenance. A case study of randomly selected buildings from the five tertiary Institutions in Owerri was adopted. Copies of structured questionnaire were administered to a sample size of 153 respondents in-charge of maintenance, using stratified systematic random sampling technique. Analysis of responses was done using descriptive and quantitative statistics. The findings revealed wrong design decisions that contributed to the defects and high maintenance frequency, such as climatic-non-compliant design concept, inaccessibility of building components, and wrong specifications. Maintenance delay caused: decline in capital value, disruption of work flow, risk of users health and safety, high cost of repairs, post-occupancy modification and acceleration of building failure. Major obstacles were: lack of maintenance culture; improper supervision; and under-funding. The paper recommended that: designers should adopt design concept responsive to tropical climate; government should increase the intervention fund giving to the institutions; while the legislature enacts laws to regulate and create awareness of maintenance culture.