Nowadays, due to the high competitiveness, projects and development of new products, must always seek out and adopt creative and viable solutions, and preferably with low implementation cost. In the automotive industry, where competitiveness is also very aggressive it becomes particularly necessary reducing costs - and therefore the opportunities should be sought, explored and adopted. This paper shows a case of adequacy of the efficiency of an old and unused existing infrastructure (originally a corrosion room), into a quiet room. An optimization of the design tuned for the room dimensions due to its inadequacy to meet the ideal sizing ratio in terms of acoustic efficiency, proved to be very successful. All design and sizing was done with the skills and knowledge available within the company, avoiding costs with external consulting (hiring of specialists) and project, combined with exploitation of existing construction, contributed decisively to the financial viability of the project.