• SPG Inc.

All About Vestibules

Updated: Dec 12, 2019

One of the most common questions I’m asked is, “Do I need a Vestibule?”  The exact language of the ICD 705 policy is as follows:


E. SCIF Door Criteria

“2. When practical, entrance doors should incorporate a vestibule to preclude visual observation and enhance acoustic protection. “



The answer is a definite “YES!”  The underlying intent of the above policy language is that you always include incorporating a Vestibule whenever possible because of the Security value it brings, including:

  • Helping to mitigate direct line of sight into the SCIF interior

  • Helping to improve acoustic integrity

  • Providing anonymity of SCIF location or existence as the unique hardware of SCIF/SAPF doors are alerting

  • Providing an additional layer of Security In-Depth (SID) against surreptitious intrusion

  • Helping to thwart “piggy backing” from someone coming into the space

  • Providing a secure area for cell phone boxes or other electronics storage


While some get confused by the language of “When practical,” it should be understood that this is only a loophole for exceptional circumstances approved by the AO, not a judgment call determined by the SCIF stakeholder.






So how big is a Vestibule?  The minimum size for a Vestibule is determined by Americans with Disabilities Act (ADA) requirements, which is determined to be a 5’ x 7’ space.  That said, the sky is the limit on how large a Vestibule can be, as long as it is meeting the spirit of the bullets listed above.  Here are some common questions I get in this regard and the answers:


Question: I am building a SCIF in my SECRET space…Do I need a Vestibule?

Answer:  Unless everyone in that SECRET space holds TS/SCI clearances, or the AO approves otherwise, then typically yes you do.

Question: I have a long access corridor leading to my SCIF space that is only accessed with a pin/prox badge reader by employees having TS/SCI clearances…Do I have to compromise SCIF square footage and build a Vestibule?

Answer:  No, you don’t need a Vestibule.  In this instance, the corridor serves as a Vestibule given the exclusive access to that area.

Question: I am building a Modular Vault that can’t exceed 20’ because of the turning radius angles of the interior space I am inserting it into, yet I need every inch of the interior for my Mission objectives and can’t afford to put in Vestibule space.  Can I just “stick build” a drywall and framed vestibule space after I get the unit into place?

Answer:  Yes.  Vestibule space is controlled space…But it is typically considered unclassified and not a part of the SCIF perimeter, so can be added later (but prior to accreditation)



Those are just a few questions, but on rare occasions I will run across someone who believes the Vestibule should be considered classified space and will put the primary SCIF door with combination lock on the “outside” of the Vestibule, with the interior door containing the pin/prox dual authentication reader.  These folks have been a small, but persistent group that show up every once in a while and I think I’ve figured out where this policy interpretation comes from.  As near as I can tell, it seems to have originated with Security professionals in the Government who either retired or migrated to the private sector and when in a position to build secure space, would mimic the environment they came from.  In the case of the Intel Community, these spaces are giant buildings that are entirely comprised of TS/SCI staff.  In these environments, the primary door to SCIF/SAPF spaces are typically right in the hallway and rarely have Vestibules.  Of course, why would Vestibules be needed in these type of environments staffed 24/7 with armed police, extensive Intrusion Detection Systems, SID and cleared TS/SCI/SAP staff?  They aren’t, but that isn’t “practical” for the rest of the SCIF/SAPF world constructed in commercial environments and Vestibules should never be constructed this way.


Vestibules are only one example of some of the complex issues surrounding SCIF/SAPF environments.  SPG understands the difficulties in navigating the murky waters of Intel Community, DoD and Industry requirements and can make your project a seamless, well-orchestrated effort, as opposed to endless “change orders” trying to fix something that wasn’t designed correctly in the first place.  Give us a call to discuss your project…We are always willing to take the time to listen to your problems and work side by side with you in engineering a first rate solution that makes your project fully policy compliant the first time around.

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