Acoustic Protection in SCIF/SAPF Construction: Navigating ICD 705 Requirements
- Alex Leutwyler
- Apr 7
- 4 min read
Ensure your SCIF or SAPF meets ICD 705 acoustic standards with these expert tips
When constructing a Sensitive Compartmented Information Facility (SCIF) or Special Access Program Facility (SAPF), physical security is only part of the equation. These secure facilities must also safeguard the conversations held within their walls. The Intelligence Community Directive (ICD) 705 Technical Specifications, commonly referred to as the Tech Spec, outlines stringent acoustic requirements to prevent sensitive discussions from being intercepted by unauthorized individuals outside the facility. In this post, we’ll break down the ICD 705 acoustic requirements for SCIFs and SAPFs, explore effective mitigation strategies, and highlight common pitfalls to avoid during construction.
Understanding ICD 705 Acoustic Requirements for SCIFs and SAPFs
A wall with acoustic insulation designed for a SCIF
The Accrediting Official (AO) determines the required Sound Transmission Class (STC) rating for a SCIF or SAPF based on the facility’s intended use, particularly whether amplified sound (e.g., speakers or audio systems) will be present. The Tech Spec defines two primary STC levels for secure facilities:
STC 45 (Sound Group 3): At this level, loud speech may be faintly audible outside the facility but remains unintelligible. Normal speech, however, is completely inaudible.
STC 50 (Sound Group 4): This higher standard ensures that even amplified sound, such as a radio at full volume or a trumpet, is barely detectable—if at all—outside the facility.
For SCIFs and SAPFs, acoustic mitigations are applied at the facility’s perimeter, where walls, doors, and penetrations play a critical role in forming an effective acoustic barrier. Failure to meet these standards can jeopardize accreditation, making it essential to prioritize acoustic protection during the design and construction phases.
Acoustic Mitigation Strategies for Secure Facilities
The Tech Spec provides three recommended wall types to meet the acoustic requirements for SCIFs and SAPFs, but these are not mandatory. As long as the AO approves, alternative constructions—such as concrete walls—can be used if they achieve the required STC rating. Here’s how to ensure your perimeter meets ICD 705 standards:
1. Multi-Layered Wall Construction
A key principle in SCIF/SAPF acoustic mitigation is the use of multi-layered wall assemblies. For an STC 45 rating, the Tech Spec recommends a three-layered wall: one layer of drywall or plywood on the uncontrolled (unsecured) side and two layers on the controlled (secure) side. To achieve STC 50, an additional layer is added to the uncontrolled side, bringing the total to four layers. These walls are filled with insulation that must be mechanically fastened to prevent slippage, which could compromise the acoustic barrier over time. All seams and gaps must be sealed with acoustic sealant to eliminate sound leaks.
2. Managing Penetrations
Penetrations, such as those for pipes or HVAC systems, are a common vulnerability in SCIF/SAPF construction. Pipes must be sealed with acoustic sealant around their entire circumference to prevent sound leakage. For HVAC systems, Z-ducts and sound baffles are effective solutions to reduce sound transmission while maintaining functionality.
3. STC-Rated Doors
Doors are often the weakest link in a SCIF or SAPF’s acoustic perimeter. To meet ICD 705 requirements, opt for a pre-assembled “door-in-a-box” solution. These assemblies include a frame, acoustic seals, hinges, and hardware, all designed to meet the specified STC rating. Proper installation by a certified installer is critical to ensure the door is sealed thoroughly around the frame to maintain its performance.
Common Mistakes in SCIF/SAPF Acoustic Mitigation
Even with the Tech Spec as a guide, mistakes during construction can undermine your facility’s acoustic security. Here are some pitfalls to avoid:
1. Improvised Door Assemblies
Some contractors attempt to build their own STC-rated doors by sourcing components from multiple manufacturers. We strongly advise against this. Even if individual parts are rated for STC 45 or 50, the assembled door may not meet the required standard when tested. Stick to pre-assembled door-in-a-box solutions to ensure compliance with ICD 705.
2. Poor Installation Practices
Even a high-quality STC-rated door can fail if not installed correctly. Inexperienced contractors may leave gaps in the sealant around the door frame, allowing sound to leak. When building a SCIF or SAPF, choose a contractor with proven experience in secure facility construction to ensure proper installation and sealing.
3. Inadequate Sealing of Penetrations
Acoustic sealant must be applied meticulously across the entire perimeter, especially around
penetrations. A single unsealed gap can compromise the facility’s STC rating. Double-check all seals before proceeding to the next construction phase to avoid costly rework.
If your SCIF or SAPF fails to meet STC requirements during testing, supplementary mitigations can help you achieve accreditation.
Supplementary Mitigations for Enhanced Acoustic Security
In addition to meeting STC requirements, the AO may mandate additional mitigations to address potential vulnerabilities in your SCIF or SAPF. These measures don’t necessarily increase the STC rating but enhance overall acoustic security:
1. Sound Masking Systems
Sound masking systems, such as transducers or speakers that emit white noise, can be installed to obscure speech and make it unintelligible outside the facility. These systems are particularly useful near potential weak points, such as doors or penetrations.
2. Stand-Off Distance
When site conditions allow, adding a second perimeter or stand-off distance can further reduce
the risk of eavesdropping. For example, a perimeter fence outside the facility can create a buffer zone, making it nearly impossible for unauthorized individuals to intercept sound.
These supplementary measures are often tailored to the specific security needs of a SCIF or SAPF, ensuring that even the most sensitive conversations remain protected.
Ready to build a SCIF or SAPF that meets the highest acoustic standards? Contact Emblem today to learn how our SCIF/SAPF consulting, design, and construction services can support your project.