It even warns that architecture schools face prosecutions brought by the Commission for Racial Equality unless more is done to promote diversity.
The study, carried out by the Policy Studies Institute, looks at the difficulties faced by 40 students and architects.
It finds that although ethnic minority students make up 18% of undergraduate architects, smaller percentages advance to Parts 2 and 3, the final stages of professional qualification.
It notes that white architecture students are four times more likely to obtain first-class degrees than ethnic minority students.
The report also found that, even at entry level, the percentage of women was much lower than in comparable professions such as law or medicine.
The existing style of teaching was called "combative" and heavily reliant on tacit knowledge, which works to the advantage of those already familiar with the profession.