ABSTRACT
Building production process (BPP) is a multi-
disciplinary and a multi-phased activity. Fragmen-
tation resulting from this structure of the building
production process brings out coordination and
integration problems, which is the main cause of
building quality problems. Nevertheless, building
quality can not be evaluated apart from building
production process. According to the researches
about the reasons of quality problems in BPP,
design stage and design failures are the most trou-
blesome cause in cost and time overruns and low
quality. Although design stage is being the most
critical phase on quality of construction projects,
it is generally neglected because total cost of the
design stage is smaller compared to the total cost
of the project. In fact, improving design quality
affects competitiveness also by decreasing looses.