ISO 27001:2022 Annex A 7.3 Securing Offices, Rooms and Facilities Explained

ISO 27001 Annex A 7.3 Securing Offices, Rooms and Facilities is an ISO 27001 control that requires an organisation to protect offices, rooms and facilities with physical security.

In this guide you will learn how to implement ISO 27001 Annex A 7.3 and pass your audit from ISO 27001 Lead Auditor Stuart Barker – author of the ultimate ISO 27001 Toolkit.

Purpose & Definition

ISO 27001 Annex A 7.3 is a preventive control that ensures you prevent unauthorised physical access, damage and interference to the organisations information and other associated assets in offices, rooms and facilities.

ISO 27001 defines ISO 27001 Securing Offices, Rooms and Facilities as:

Physical security for offices, rooms and facilities should be designed and implemented.

ISO27001:2022 Annex A 7.3 Securing Offices, Rooms and Facilities

ISO 27001 Annex A 7.3 Training Video

In this free training video you will learn How to implement ISO 27001 Securing Offices, Rooms and Facilities (Annex A 7.3) and Pass Your Audit.

Implementation Guide

General Guidance

You are going to have to

• consult a legal professional to ensure you operate within the law and regulation
• only allow people you authorise into buildings, sites and physical locations
• implement physical security controls based on risk and business need

Considerations

There are considerations that may be appropriate

• consider putting confidential and sensitive information processing where it cannot be accessed by the public
• being aware of external building signage so as not to highlight information processing
• stopping people outside the physical boundary from seeing in or listening in
• electromagnetic shielding if you are NASA
• restricting access to internal contact directories and maps to those that need to know

The implementation of securing offices, rooms and facilities is in the context of the physical security perimeter where you can find guidance in the Ultimate guide to ISO 27001 Annex A 7.1 Physical Security Perimeter.

Health and Safety

Your number one priority is to meet the requirements of law and regulation. Be sure to engage with a legal professional to understand what you can and cannot do and to check that you are not breaking any laws. The most significant laws are those around health and safety as the protection of human life and wellbeing is always our number priority. There are common things that should be considered such as entry point doors that fail open. Whilst we want to protect buildings and information our absolute priority is to protect people.

Define your access control requirements

Start by understanding your risk and doing a risk assessment. For guidance on how, read The Complete Guide to ISO 27001 Risk Assessment. This is going to be based on the needs of the business and the risks that you are managing. As a starting point there are basics such as having locks on doors but you can asses the strength of those locks and if other additional controls such as bio metrics or gates are required. Do what is right for you. Consider the environment around the location and the threats that may be posed and be sensible in addressing them.

Topic specific physical and environmental security policy

To communicate to people what you do and what is expected you are going to write, sign off, implement and communicate your topic specific Physical and Environmental Security Policy.

Secure Areas

The standard gives the guidance that a secure area can be an office that is locked or some internal area that has an internal security barrier. It takes into account that your physical locations maybe internal sub divided based on protection requirements. Usually this is implemented when you have a file room, an archive room, or a room where you store old IT equipment. On premises data centres and data rooms fall into this category as well but in this day and age they are few and far between with most people adopting a cloud based strategy.

How to implement ISO 27001 Annex A 7.3

Implementing ISO 27001 Annex A 7.3 requires a tiered approach to internal physical security, ensuring that sensitive offices and rooms are protected by perimeters that are proportionate to the risks identified.

1. Categorise and Map Internal Secure Areas

Conduct a physical site survey to identify and classify rooms based on the sensitivity of the data or hardware they contain.

• Identify high-value areas such as server rooms, communications cupboards, and executive offices.
• Define the required security perimeter for each zone based on a formal Risk Assessment.
• Document the boundaries of these “Secure Areas” within the Physical Security Policy.
• Ensure that internal walls extend from floor to ceiling (slab-to-slab) to prevent unauthorised overhead access.

2. Provision Multi-Layered Access Controls

Deploy physical and electronic barriers to ensure that only authorised personnel with a verified business need can enter restricted zones.

• Install electronic Physical Access Control Systems (PACS) using encrypted fobs or biometric scanners.
• Provision Multi-Factor Authentication (MFA) for entry into high-criticality areas like the primary data centre.
• Assign access rights based on specific IAM roles, ensuring the principle of least privilege is applied to the physical site.
• Configure automated alerts for “door held open” or “forced entry” events.

3. Implement Environmental and Hazard Protection

Integrate protective measures to shield internal facilities from accidental or natural environmental threats that could compromise equipment availability.

• Install automatic fire detection and gas-based suppression systems in server rooms to mitigate thermal risks without water damage.
• Deploy water leak detection sensors beneath raised floors or near AC units.
• Utilise fire-rated doors and partitions for all rooms designated as secure zones.
• Maintain a maintenance log for all environmental sensors to serve as audit evidence.

4. Formalise Visitor Management and Supervision Protocols

Establish strict rules for the movement of unvetted individuals within internal facilities to prevent opportunistic data theft or tampering.

• Maintain a formal Register of Entrants (ROE) for all visitors, contractors, and third-party maintenance staff.
• Mandate constant supervision (escorting) for any visitor entering a secure room.
• Issue visually distinct temporary ID badges that must be displayed at all times.
• Record the purpose of the visit and the identity of the internal host for every entry event.

5. Revoke Access and Audit Physical Logs

Perform regular reviews of physical access rights and logs to ensure the continued integrity of secure offices and facilities.

• Revoke physical badge access immediately upon staff termination or role change.
• Audit PACS logs monthly to identify anomalous entry patterns or attempted unauthorised access.
• Conduct quarterly “floor walks” to verify that doors are not being propped open and locks remain functional.
• Document all findings and corrective actions within the ISMS continuous improvement log.

Policy Template

For ISO 27001 Annex A 7.3 Securing Offices, Rooms and Facilities you need a topic specific Physical and Environmental Security Policy Template.

How to pass the audit

To comply with ISO 27001 Annex A 7.3 you are going to implement the ‘how’ to the ‘what’ the control is expecting. In short measure you are going to

• Define your physical access requirements
• Define your internal sub zone physical perimeter requirements
• Consult with a legal professional to ensure you are meeting legal and regulatory requirements
• Implement your physical security access
• Write, sign off, implement and communicate your topic specific Physical and Environmental Security Policy
• Write, sign off, implement and communicate your perimeter incident response procedures
• Implement a process of internal audit that checks that the appropriate controls are in place and effective and where they are not follow the continual improvement process to address the risks

What the auditor will check

The audit is going to check a number of areas. Lets go through them

1. That you have a physical entry control

One of the easier things for an auditor to check is the physical entry controls as it is usually the first thing they will encounter when they come to audit you if you have a physical location. For all the physical locations in scope they are going to visit and check.

2. The strength of the physical security access

They have been doing this a long time and done many audits so they know what to look for. They will test the controls and see what happens. They will try to open doors, open cupboards, gain access to areas they should not.

3. Documentation

They are going to look at audit trails and all your documentation. They will look at appropriate access reviews, logs of monitors and reports, incidents and how you managed them.

Top 3 mistakes and how to avoid them

The top 3 mistakes people make for ISO 27001 Annex A 7.3 are

1. Your physical security perimeter is turned off

What do I mean by turned off? In simple terms it means that you have a lockable door that should be locked and it not locked. You have a fire door that should be closed and locked but you have propped it open because it is a hot day.

2. One or more members of your team haven’t done what they should have done

Prior to the audit check that all members of the team have done what they should have. Have access reviews taken place? Who gets informed about about the alarm and do they still work here? 

3. Your document and version control is wrong

Keeping your document version control up to date, making sure that version numbers match where used, having a review evidenced in the last 12 months, having documents that have no comments in are all good practices.

ISO 27001 Annex A 7.3 FAQ

Related ISO 27001 Controls

• ISO 27001 Annex A 7.6 Working In Secure Areas
• ISO 27001 Annex A 7.5 Protecting Against Physical and Environmental Threats

ISO 27001 Annex A 7.3 Attribute Table

Control type	Information security properties	Cybersecurity concepts	Operational capabilities	Security domains
Preventive	Confidentiality	Protect	Physical security	Protection
	Integrity		Asset Management
	Availability