Item 7A Narrative 12 June 2017
Richard Schell
City of Southlake
C 0 R G A N
Re: ZA17-044 TDDC ASC Southlake Acoustic Study Summary
ARCHITECTURE
INTERIOR DESIGN Dear Mr. Schell:
During permitting we were made aware of the acoustical ordinance. We sent the building shell
design to the acoustical engineer. When we discussed the design, he indicated that based on
high level calculations with the amount of glazing shown in the front of the building, we would
WWW.C O R G AN.COM not be able to meet the ordinance. We reduced storefront behind the blade wall to punched
openings to offset the amount of glass we kept in front of the blade wall. We discussed several
options with the acoustical engineer to improve the performance of the envelope. We
reviewed the following concepts:
• Added additional layer of gyp on roof insulation
• Revised the glass window system to a high performance Laminated glass
• Revised the glass window system by Increasing airspace between panes
• Evaluated multiple insulating laminated (on one side)choices offered by Viracon
with greater than '/2' airspace. Narrowed the field to seven options and then
selected two that will work that we believe are best suited for this project.
• Built an insulated partition behind the spandrel glazing that was above the ceiling
elevation
We incorporated these options to improve the acoustic performance but were still required to
reduce the amount of glass. We contacted the city staff to see if there was any way to request
a variance and were told that a variance was not an option.
Sincerely,
Truby McDougal
Vice President
CORGAN