Project Type: Government
Lancaster City Hall
Architect: Cox Evans Architects
When the historic Lancaster City Hall building was set to undergo a major transformation in the form of an 18,000 square foot addition, Metropolitan Acoustics was brought in to consult on the acoustics and sound control throughout the entire new space. The main design objectives from an acoustical point of view were to limit unwanted noise attenuation and prevent echoes and reverberation in various rooms throughout the new addition.
The Council Chambers and Commission Room share walls with offices, stairwells, and corridors while the spaces above the chambers are designated as offices. These are conditions that are fairly common in multi-use buildings such as this, and are conditions which require solutions to limit the amount of sound transference from one room to another. In this particular setting, the desire was to keep the sound from the proceedings in the Council Chambers from intruding into the private offices and public corridors nearby. The requirements for the chambers themselves were different in nature– they needed proper acoustics in order to provide clear and natural amplification of voices throughout the room.
For sound control, our analysis and recommendations included a comprehensive list of construction methods, materials, and finishes which were designed to limit the transmission of sound from the public spaces to the private offices and meeting rooms. Our solutions involved everything from wall construction recommendations to the proper method and application of sealants around penetrations in the walls above the ceiling tiles. Our acoustic solutions for the Chambers and Commission Room involved an overall analysis of the design parameters using predictive computer modeling and the absorptive and reflective properties of the proposed material selections.
Once construction was complete, we conducted testing on site to measure reverberation time and background sound levels. The results were impressive. In terms of sound control, we achieved a greater result than promised, and in terms of acoustics, the reverberation rate was even lower than expected and there were no flutter echoes present in any of the rooms.