Office Building and Multi-Tenant Property Security

Ask any property manager where the system fails and the answer is tailgating. Someone badges in and two people walk through. It happens at the main lobby line and again at tenant suite doors, and card readers alone cannot see it.

The physical answer is a controlled lobby line: optical turnstiles or speed gates with anti-tailgating and anti-passback detection, plus an ADA gate that is supervised rather than propped. The electronic answer is pairing every lobby transaction with a camera view at identification grade so a denied or forced event produces a usable image, not a log entry.

Tenant suite doors need the same thinking at smaller scale. A reader with a door position switch and a camera on the approach turns a suite door from a lock into a record.

Write the demarcation down before anyone buys hardware. Landlord scope is normally the perimeter, lobby, elevators, elevator lobbies, garage, loading dock, stairwells and common corridors. Tenant scope begins at the suite door.

Two systems is acceptable. Two systems with no agreed process is not. At minimum, define who revokes a credential when a tenant employee leaves, who receives an alarm at 2 a.m., who can request video and in what format, and how long common-area video is retained.

Where a tenant wants its own access platform, we design the suite door so the landlord retains a monitored door position and a life safety path, and the tenant retains its own credential database. Both parties get what they need without arguing about it later.

Every move-out is a credential event. Cards do not come back. Contractors keep fobs. Suites get re-keyed and the access database does not get cleaned. Three years of churn later, nobody can say how many active credentials exist or who holds them.

Two practices fix this. First, mobile credentials, because a mobile credential is revoked centrally and cannot be handed to a friend as easily as a card. Second, a scheduled audit tied to the lease calendar: at every move-out, credentials for that suite are bulk-revoked and the exception list is reviewed by a person.

If the building still runs on legacy low-frequency proximity cards, that is worth addressing on its own merits. Those credentials are trivially cloned with equipment that costs less than a lunch.

Elevator integration is what makes after-hours access real. During business hours the cab is open to lobby traffic. After hours, a credential should authorize only the floors that credential belongs to. Without that, a single lobby breach reaches every tenant on the stack.

Freight elevators and loading docks are the most abused openings in an office building. They are propped for deliveries, used by contractors and often the only unwatched path to the core. Dock coverage plus a door position switch plus a schedule usually resolves years of unexplained after-hours activity.

Trash rooms, telecom closets and roof access are the other three doors that get overlooked. All three should be credentialed and logged.

Denver metro office vacancy sat near 28.7 percent in Q2 2026, with downtown Denver closer to 38.6 percent. Those figures move every quarter, so treat them as direction rather than gospel. The security consequence does not move.

Half-empty floors mean unmonitored corridors. That produces copper and wire theft from vacant suites, HVAC and mechanical theft, squatting, stairwell vandalism, and after-hours access by people who know a floor is dark. Most owners have not re-scoped their camera and access design since the floor emptied.

Re-scoping is cheap compared to a copper loss. Cameras get repointed to elevator lobbies on vacant floors, stair doors on dark floors get monitored, vacant suite doors get a position switch, and after-hours rules get tightened by floor rather than by building.

A complete multi-tenant scope covers a predictable list. Ranges apply as always: 1,000 to 2,500 dollars per camera installed and 1,500 to 3,500 dollars per door.