Many non-specialists 'in acoustics have frequently to deal with the problem of commissioning a classroom or auditorium for its overall speech intelligibility. This paper outlines the pitfalls and the general misconceptions, which arise in such projects. A major facility in ITTHO - The Main Hall used for speech and is considered as a case study to validate the objectives. Results of the progress are reported in this work from the early commissioning by the second author in 1994 to the final recommendations at the present time. These recommendations are the result of sustained and repeated acoustic tests over a period of eighteen months from June 1996 to November 1997 investigated by the first author who is an acoustic specialist.