Design Factors Influencing Quality of Building Projects in Nigeria: Consultants' Perception

Various factors identified from the literature that caninfluence quality of building projects in Nigeria have beenstudied by means of questionnaire survey sent to architects,engineers and quantity surveyors in the industry. From atotal response of 107 consultants, the importance of eachfactor was obtained via severity and frequency responsesof the factors. Data analysis includes comparisons ofranking among consultants using severity, frequency andimportance indexes, correlation analysis, and percentagerank agreement factor (PRAF) to measure the agreement inthe importance ranking among the consultants.Correlation results between the professionals are architects/quantity surveyors (0.75), architects/engineers (0.21 ),and engineers/quantity surveyors (0.24). The percentagerank agreement factor (PRAF) shows that the five mostimportant factors affecting quality are 'design changes'(78.9%); 'inadequate involvement of other professionalsduring the design stage' (78.9%); 'insufficient andunrealistic constraints of project cost' (71.1 %); 'poor levelof commitment to quality improvement among designprofessionals' (63.2%); and 'making design decisions oncost and not value of work' (55.3%). The results of this studywould provide feedback for the clients, project and qualitymangers and all the consultants in the industry, so thateffective management of quality can be ensured from theconceptual-design stage of the project