SLYYYDEHVAC
RESEARCH // OT SECURITY

Building automation cybersecurity for HVAC teams

A practical starting point for reducing remote-access, patching, identity, and network risks in building automation systems.

10 min readUpdated September 22, 2026Audience: For facilities leaders, controls contractors, building owners, IT teams, and BAS operators.

Short answer: HVAC cybersecurity begins with asset visibility, controlled remote access, identity management, network boundaries, backup and recovery, patch governance, and an operating owner who can respond when conditions change.

01

The BAS is operational technology

A building automation system can affect comfort, ventilation, equipment runtime, alarms, access, and business continuity. Its security needs to account for safety and availability, not only confidentiality. Start by identifying controllers, servers, gateways, remote tools, vendor accounts, network paths, and the people responsible for each layer.

02

Remote access deserves a named owner

Remote access should be necessary, time-bounded where possible, authenticated, logged, and reviewed. Remove unused accounts, apply multi-factor authentication where supported, document vendor access, and define the response when a credential or connected system is compromised. Convenience without ownership is a recurring operational risk.

03

Patch decisions need building context

A patch can change controller behavior or interrupt a critical system, so patch governance needs testing, scheduling, rollback, backups, and communication. That does not justify leaving known vulnerabilities unmanaged. Record the asset, software version, vendor guidance, maintenance window, risk decision, and next review date.

04

Make recovery part of the design

A system is not resilient because it has a backup file that nobody has tested. Document how to restore controllers, servers, graphics, schedules, sequences, credentials, and network dependencies. Run a tabletop exercise with facilities, controls, IT, and vendors so the first response is not improvised during a comfort or safety event.

NEXT ACTION

Add cybersecurity readiness to the HVAC operating assessment.

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