That mix is a workplace-operations problem: cleared-only zones need booking permissions that respect vetting status, visitors need escorting rules, and an accurate live record of who is where stops being admin and starts being a security control. See visitor management and access control.
Common questions
What does Security Clearance mean in simple terms?+
Security clearance is the vetting that controls who may access certain government buildings, zones and information, from baseline checks through to the highest national security levels. Many public-sector sites mix clearance levels in one building.
What are the rules around Security Clearance?+
That mix is a workplace-operations problem: cleared-only zones need booking permissions that respect vetting status, visitors need escorting rules, and an accurate live record of who is where stops being admin and starts being a security control. See visitor management and access control.