BAA is a customer-oriented firm that provides great service while producing a well-designed and coordinated project. Our experience allows us to identify problems and solve them during the design phase rather than in the construction phase. Proficient in BIM modeling and traditional AutoCAD. BAA Mechanical Engineers Inc., formerly Britt Alderman Associates, is a Consulting Engineering Firm in the midtown Atlanta area specializing in HVAC, Plumbing and Fire Protection design. The firm was established in 1946 by Britt Alderman Jr, who worked with architect John Portman, among others, to create in many ways the downtown modern Atlanta skyline.