Case studies of recent experiences with the International Building Code Requirements for Background Sound Levels in Educational Spaces

For K-12 Education spaces, requirements for maximum background sound levels of 35 dBA and 55 dBC for sound sources inside and outside the classroom, to be evaluated separately, and maximum reverberation times were included in Section 808 A117.1 of the International Building Code in 2021. These requirements were adopted in Section 1211 of the Florida Building Code in 2023. Major school districts in Florida are having to adapt their design standards for new and renovated schools to meet these requirements. Acoustical measurements of background sound levels were made of HVAC system noise levels in selected rooms in three existing schools to determine if the classrooms as currently designed meet the sound level limits in the code. The measured sound levels are compared to the required sound levels. Some acoustical mitigation elements will likely be required in many classrooms to achieve the 35 dBA and 55 dBC sound level limits. The code calls for sound levels to be measured during the greatest 1 h period of time. While this may be typical for exterior sources of sound, it is not generally typical for HVAC noise measurements to be taken over multiple hours, presenting practical issues when surveying a large number of rooms.