Building collapse is usually an outcome of progressive deterioration
of the various components forming the building unit. This paper identifi ed and
assessed the nature and sources of both the generic and specifi c causes of failure
of building components in Nigeria. Osun State was purposively sampled for the
study. Data were obtained through use of a structured questionnaire, and results
were analysed using a relative importance index. Analysis showed that building
components tend to fail at different rates depending on the materials, designs,
method of construction, environmental conditions and the use to which the building
is put. Substandard materials and design errors were identifi ed as major causes
of component failure. The specifi c causes of failure of building components, apart
from substandard materials and design errors, relate primarily to construction
method and the use of the various components.