ISO 23601 Explained: Safety Evacuation Plan Design and Requirements

ISO 23601, titled "Safety identification — Escape and evacuation plan design," is the international standard that specifies the design requirements for posted evacuation plans displayed in buildings and structures. The standard defines the content, graphical conventions, colour specifications, symbol usage, scale requirements, and placement criteria that evacuation plans must meet to provide clear, consistent guidance to building occupants during emergencies. ISO 23601 draws heavily on ISO 7010 for its safety symbol vocabulary and on ISO 3864 for its colour and design framework. This guide examines the standard's purpose, the mandatory content of an evacuation plan, the colour system (green, red, yellow, blue), symbol requirements, scale and dimension rules, mounting and placement guidance, update frequency obligations, its relationship to DIN 23601 and national equivalents, and the growing adoption of digital evacuation plan creation through platforms like Plotstuff.

Table of Contents

1. What Is ISO 23601
2. Purpose and Scope
3. Plan Content Requirements
4. Colour Specifications
5. Symbol Usage and ISO 7010 Reference
6. Scale Requirements
7. Dimensions and Layout
8. Mounting and Placement
9. Update Frequency and Revision Management
10. Relationship to DIN 23601 and National Equivalents
11. Digital Evacuation Plan Creation
12. Common Errors in Evacuation Plan Design
13. Key Takeaways
14. Frequently Asked Questions
15. Next Steps

What Is ISO 23601

ISO 23601 is an international standard that establishes the requirements for the design of escape and evacuation plans displayed in buildings. These are the plans mounted on walls in corridors, lobbies, hotel rooms, and other locations to show occupants the building layout, emergency exit routes, locations of fire-fighting equipment, assembly points, and the "You are here" marker.

The standard was developed to address the inconsistency of evacuation plans across countries. Before ISO 23601, evacuation plan design varied widely. Some plans used architectural drawing conventions with technical hatching and dimensioning. Others used arbitrary colour schemes, non-standard symbols, or no colour at all. The result was that occupants could not reliably interpret unfamiliar evacuation plans, particularly under the stress and reduced cognitive capacity that characterise emergency situations.

ISO 23601 solves this problem by specifying a standardised format that any observer should be able to interpret, regardless of their familiarity with the specific building. The standard prescribes specific colours for specific elements, mandates the use of internationally recognised safety symbols from ISO 7010, and establishes rules for scale, orientation, and placement.

The standard is maintained by ISO Technical Committee TC 145 (Graphical symbols), Subcommittee SC 2 (Safety identification, signs, shapes, symbols and colours).

Purpose and Scope

Primary Purpose

The primary purpose of ISO 23601 is to enable building occupants to:

• •Identify their current location within the building using the "You are here" marker.
• •Identify the nearest emergency exit and the route to reach it.
• •Locate fire-fighting equipment (extinguishers, hose reels, fire blankets) along the exit route.
• •Identify the external assembly point where they should gather after evacuating.
• •Understand emergency procedures summarised in the plan legend.

Scope of Application

ISO 23601 applies to evacuation plans for:

• •Commercial buildings (offices, retail, hospitality).
• •Industrial facilities (factories, warehouses, laboratories).
• •Public buildings (hospitals, schools, government buildings).
• •Residential buildings (apartment blocks, student accommodation).
• •Transport infrastructure (airport terminals, railway stations).
• •Temporary structures (exhibition halls, event venues).

The standard applies to plans displayed as wall-mounted posters. It does not directly address digital evacuation plans displayed on screens or in mobile applications, although its design principles are widely adopted for digital formats.

Relationship to Evacuation Route Planning

ISO 23601 addresses the visual representation of evacuation information on a posted plan. The underlying evacuation route planning, including the determination of escape routes, travel distances, exit capacity, and assembly point locations, is a separate discipline governed by national fire safety regulations and building codes. ISO 23601 provides the means to communicate the results of that planning to building occupants.

Plan Content Requirements

ISO 23601 specifies that every evacuation plan must contain the following elements:

Mandatory Elements

1. Floor plan layout: A simplified plan of the floor or zone in which the plan is posted. The plan should show walls, doors, corridors, stairways, and other structural features in sufficient detail for occupants to orient themselves, but should omit unnecessary detail such as furniture, dimensions, and mechanical services.

1. Escape routes: The designated escape routes must be marked clearly, showing the direction of travel from the "You are here" location to the nearest emergency exits. Primary and secondary (alternative) escape routes should be distinguished where applicable.

1. Emergency exits: All emergency exits on the floor must be marked with the appropriate ISO 7010 safe condition symbol (E001 or E002).

1. You are here marker: A clearly marked indicator showing the plan's mounting location within the building. This is the single most important element for orientation. The "You are here" marker must be placed accurately and must be obvious to the observer.

1. Fire-fighting equipment locations: The positions of fire extinguishers, fire hose reels, fire blankets, fire alarm call points, and other fire-fighting equipment must be marked using ISO 7010 fire equipment symbols (F series).

1. First aid equipment locations: First aid boxes, defibrillators, and emergency showers should be marked using ISO 7010 safe condition symbols where relevant.

1. Assembly point: The external assembly point where occupants should gather after evacuating must be indicated, typically on a separate site plan or as an annotation on the floor plan.

1. Legend: A legend explaining all symbols used on the plan. The legend should reference the ISO 7010 symbol codes where applicable.

1. Emergency telephone numbers: Contact numbers for the fire brigade, ambulance, and building emergency control must be displayed.

1. General emergency procedures: Brief text instructions summarising the actions to take upon discovering a fire or hearing an alarm. These typically include "Do not use lifts," "Close doors behind you," and "Go to assembly point."

Optional Elements

• •Floor identification (floor number or name).
• •North point or orientation indicator.
• •Grid reference system for large or complex floors.
• •QR code linking to a digital evacuation plan or additional emergency information.

Colour Specifications

ISO 23601 prescribes specific colours for specific elements of the evacuation plan. The colour system is derived from ISO 3864 safety colour definitions.

Green

Green is used for:

• •Escape routes (the path from the "You are here" marker to emergency exits).
• •Emergency exit symbols.
• •Assembly point markers.
• •Safe condition information.

The green used must conform to the safety green defined in ISO 3864-1, specified as a CIE colour within defined chromaticity coordinates. In print production, the green is typically specified as Pantone 3415 or a CMYK equivalent.

Red

Red is used for:

• •Fire-fighting equipment symbols and their locations.
• •Fire alarm call point symbols.
• •Prohibition information (if any prohibition signs are shown on the plan).

The red must conform to the safety red defined in ISO 3864-1.

Yellow

Yellow is used for:

• •Warning information (if any warning symbols are shown on the plan, such as hazardous material storage areas).
• •Yellow is used sparingly on evacuation plans, typically only when the plan includes hazard zones that occupants should avoid during evacuation.

Blue

Blue is used for:

• •Mandatory action information (if any mandatory symbols are shown on the plan).
• •Blue is also used sparingly, typically only when the plan includes areas where specific actions are required (for example, zones where respiratory protection must be worn).

Background and Structural Elements

The building structure (walls, doors, corridors) is typically rendered in black or dark grey on a white background. The white background ensures maximum contrast for the coloured escape routes and symbol markers.

Contrast and Legibility

The colour specifications are designed to ensure that the plan is legible under normal lighting conditions and, where photoluminescent materials are used, under emergency lighting conditions. The colour choices follow the principle that safety-critical information (escape routes in green, fire equipment in red) should be the most visually prominent elements on the plan.

Symbol Usage and ISO 7010 Reference

Mandatory Symbol Set

ISO 23601 requires that all safety symbols used on evacuation plans conform to ISO 7010. The standard does not permit the use of non-standardised or proprietary symbols for safety information. This ensures that anyone familiar with ISO 7010 symbols (which are increasingly universal) can interpret the evacuation plan correctly.

The most commonly used ISO 7010 symbols on evacuation plans include:

Safe Condition (E Series):

• •E001: Emergency exit (left).
• •E002: Emergency exit (right).
• •E003: First aid.
• •E007: Assembly point.
• •E010: Automated external defibrillator (AED).

Fire Equipment (F Series):

• •F001: Fire extinguisher.
• •F002: Fire hose reel.
• •F005: Fire alarm call point.

Prohibition (P Series) (used selectively):

• •P020: Do not use lift in case of fire.

Warning (W Series) (used selectively):

• •W001: General warning (for hazard zones).

Symbol Size on Plans

Symbols on the evacuation plan must be large enough to be legible at the expected reading distance. ISO 23601 does not prescribe exact symbol dimensions, but the symbols must be proportionate to the plan size and must remain recognisable when printed at the plan's working scale. A common guideline is that symbols should not be smaller than 7 mm in height on the printed plan.

Symbol Placement

Symbols must be placed at the locations they represent on the floor plan. A fire extinguisher symbol should appear on the plan at the point corresponding to the extinguisher's actual location in the building. This spatial accuracy is essential because the plan serves as a map; displaced symbols would direct occupants to the wrong location.

Scale Requirements

Scale Consistency

ISO 23601 requires that evacuation plans be drawn to a consistent scale. The entire floor plan should use a single scale so that distances and proportions are represented accurately. This allows occupants to estimate real distances from the plan, which is important for choosing between alternative escape routes.

Recommended Scale Ranges

The standard does not mandate a single scale value, recognising that buildings vary greatly in size. However, the plan must be large enough for all required information to be legible at the expected reading distance (typically 0.5 to 1.0 metres for a wall-mounted plan). Common scale ranges include:

• •Small buildings or individual zones: 1:100 to 1:200.
• •Medium buildings: 1:200 to 1:500.
• •Large buildings or site plans: 1:500 to 1:1000.

Scale Indication

The plan should include a graphic scale bar or a written scale ratio so that observers can interpret distances. A graphic scale bar is preferred because it remains accurate even if the plan is reproduced at a different size from the original.

Dimensions and Layout

Plan Orientation

The evacuation plan should be oriented so that the direction the observer faces when viewing the plan corresponds to the top of the plan. This "heads-up" orientation is critical for intuitive wayfinding. If the plan is mounted on a north-facing wall, the north direction should be at the top of the plan, matching the observer's perspective. A plan oriented contrary to the observer's viewpoint causes confusion and delays during an emergency.

Minimum Plan Size

ISO 23601 recommends a minimum plan size that ensures legibility. While specific dimensions depend on the building complexity and the amount of information to be displayed, a common minimum is A3 (297 x 420 mm). Larger formats (A2, A1) are used for complex floors with many features.

Layout Structure

A typical ISO 23601 evacuation plan layout includes:

• •The floor plan occupying the central portion of the sheet.
• •The plan title and floor identification at the top.
• •The legend and symbol key along one side or at the bottom.
• •Emergency telephone numbers and procedures in a clearly bordered panel.
• •The "You are here" marker prominently placed on the floor plan.

Mounting and Placement

Location Selection

Evacuation plans must be posted at locations where occupants are most likely to see them and most likely to need evacuation guidance. ISO 23601 specifies that plans should be placed:

• •At or near all main entrances and exits.
• •At lift lobbies and stairwell entrances.
• •At corridor junctions and decision points.
• •In hotel rooms, hospital rooms, and other individual occupancy spaces.
• •At assembly areas (showing the assembly point location and re-entry procedures).

Mounting Height

Plans should be mounted at a height that is comfortable for reading while standing. A common specification is for the centre of the plan to be between 1400 mm and 1600 mm above finished floor level. This range accommodates both standing and seated (wheelchair) users, consistent with ISO 21542 accessibility requirements.

Protection and Durability

Evacuation plans must be protected against damage, fading, and defacement. Common protection methods include:

• •Encapsulation in a rigid frame with a clear protective cover.
• •Lamination for paper-based plans.
• •Direct printing on durable substrates (aluminium composite panel, acrylic, or photoluminescent material).

Photoluminescent evacuation plans, which remain visible during power failures, are increasingly specified by national fire codes and are recommended as best practice by ISO 23601.

Update Frequency and Revision Management

When Plans Must Be Updated

ISO 23601 requires that evacuation plans be updated whenever there is a change that affects the accuracy of the information displayed. Triggers for an update include:

• •Changes to the building layout (new walls, relocated doors, blocked corridors).
• •Changes to escape routes (new exits, closed exits, modified routes).
• •Relocation of fire-fighting equipment.
• •Changes to assembly point locations.
• •Changes to emergency telephone numbers or procedures.
• •Building refurbishment, extension, or change of use.

Regular Review

Even in the absence of specific changes, evacuation plans should be reviewed at regular intervals to confirm their accuracy. A common review frequency is annually, aligned with fire risk assessment reviews. Some national regulations specify a minimum review frequency.

Revision Records

Each evacuation plan should carry a revision number and date, allowing building management to verify that the most current version is displayed. When a plan is revised, all copies of the previous version must be removed and replaced.

The Challenge of Manual Updates

One of the persistent challenges with evacuation plan management is the time and cost required to update paper-based plans. A single building may have dozens of posted evacuation plans, each requiring individual revision, printing, and replacement whenever a change occurs. This is a significant driver behind the adoption of digital evacuation plan tools, which can propagate updates across all plan instances from a single source.

Relationship to DIN 23601 and National Equivalents

DIN 23601

DIN 23601 was the German national standard for evacuation plans, published before the ISO 23601 international standard. DIN 23601 established many of the design principles that were subsequently adopted by ISO 23601, including the colour system, "You are here" marker, and heads-up orientation rule. Germany was a significant contributor to the development of ISO 23601, and the two standards are closely aligned.

Following the publication of ISO 23601, Germany adopted the international standard as DIN ISO 23601, formally replacing the original DIN 23601. Existing plans designed to DIN 23601 are generally compliant with ISO 23601, although minor differences may exist.

Other National Equivalents

Other countries have adopted ISO 23601 either directly or through equivalent national standards:

• •United Kingdom: BS ISO 23601.
• •France: NF ISO 23601.
• •Australia: Evacuation plan requirements are specified in AS 3745, which references ISO 23601 principles.
• •United States: NFPA 170 (Standard for Fire Safety and Emergency Symbols) provides a U.S. perspective on evacuation plan symbols, though ISO 23601 is increasingly referenced in international projects.

Harmonisation Benefits

The international adoption of ISO 23601 means that evacuation plans in a hotel in Berlin, an office in London, and a hospital in Sydney should follow the same design conventions. This consistency benefits international travellers, multinational organisations, and emergency responders who may need to interpret evacuation plans in unfamiliar buildings.

Digital Evacuation Plan Creation

The Shift to Digital

The traditional process for creating evacuation plans involves a fire safety consultant or architect manually drawing the plan using CAD software or generic illustration tools, printing it, and mounting it in the building. This process is time-consuming, expensive, and creates a maintenance burden because any change requires the entire process to be repeated.

Modern spatial infrastructure software such as Plotstuff is transforming this process by enabling evacuation plans to be generated directly from digital floorplans. The floorplan provides the building layout; the software adds escape routes, ISO 7010 symbols, the "You are here" marker, legend, and emergency information in accordance with ISO 23601.

Advantages of Digital Creation

Digital evacuation plan creation offers several advantages:

• •Speed: Plans can be generated from existing digital floorplans in a fraction of the time required for manual drafting.
• •Consistency: The software enforces ISO 23601 colour specifications, symbol standards, and layout rules, reducing the risk of non-compliant plans.
• •Scalability: Multiple plans for different mounting locations can be generated automatically, each with the correct "You are here" marker and orientation.
• •Update efficiency: When the building layout changes, the floorplan is updated once, and all derived evacuation plans are regenerated automatically.
• •Integration: Digital evacuation plans can be integrated with fire safety management systems, linking plan data to inspection records, equipment registers, and compliance documentation.

Print and Display Options

Digital evacuation plans can be output in multiple formats:

• •High-resolution PDF for professional printing on paper, aluminium composite, or photoluminescent substrates.
• •SVG or vector format for large-format printing without quality loss.
• •Screen-optimised format for display on digital screens, kiosks, or mobile applications.
• •Interactive format with clickable symbols linking to equipment details or inspection records.

Common Errors in Evacuation Plan Design

Understanding common errors helps practitioners avoid non-compliance and produce plans that genuinely aid building occupants during emergencies.

Incorrect Orientation

The most common and most dangerous error is mounting a plan with incorrect orientation. If the plan does not match the observer's viewpoint, the observer will turn in the wrong direction, potentially moving toward the fire rather than away from it. Every plan must be oriented so that "up" on the plan corresponds to the direction the observer is facing.

Missing or Inaccurate "You Are Here" Marker

A plan without a "You are here" marker is almost useless because the observer cannot determine their starting point for route-finding. An inaccurately placed marker is arguably worse, as it provides false positional information.

Non-Standard Symbols

Using proprietary, outdated, or non-standard symbols instead of ISO 7010 symbols creates comprehension barriers. Observers familiar with ISO 7010 will not recognise non-standard symbols, and the plan loses its language-independent communication ability.

Outdated Plans

Plans that do not reflect the current building layout are dangerous. Blocked exits shown as open, or new exits not shown at all, can lead occupants into dead ends or cause them to miss viable escape routes.

Excessive Detail

Including too much architectural detail (furniture, equipment, dimensions, grid references) clutters the plan and obscures the safety-critical information. The floor plan should be simplified to show only the structural elements necessary for orientation.

Inadequate Size or Legibility

Plans that are too small or printed at too low a resolution are difficult to read, particularly under emergency conditions when occupants may be stressed, smoke may reduce visibility, or lighting may be compromised.

Key Takeaways

• •ISO 23601 specifies the design requirements for wall-mounted evacuation plans, ensuring consistency and comprehensibility across buildings and countries.
• •Every plan must include a floor plan, escape routes, emergency exits, "You are here" marker, fire equipment locations, assembly point, legend, and emergency procedures.
• •The colour system uses green for escape routes and safe conditions, red for fire equipment, yellow for warnings, and blue for mandatory actions, all derived from ISO 3864.
• •All safety symbols on the plan must conform to ISO 7010.
• •Plans must be drawn to a consistent scale, oriented to match the observer's viewpoint, and mounted at locations where occupants are most likely to need evacuation guidance.
• •Plans must be updated whenever the building layout, escape routes, equipment locations, or procedures change, with regular reviews at least annually.
• •ISO 23601 has been adopted internationally, replacing or aligning with national equivalents such as DIN 23601.
• •Digital tools such as Plotstuff streamline evacuation plan creation, enforcement of ISO 23601 requirements, and ongoing plan maintenance.

Frequently Asked Questions

What is the difference between ISO 23601 and DIN 23601?

DIN 23601 was the German national standard for evacuation plans that predated ISO 23601. The two standards are closely aligned because Germany contributed significantly to the development of the international standard. Germany has since adopted ISO 23601 as DIN ISO 23601, formally superseding the original DIN 23601. Plans designed to DIN 23601 are generally compliant with ISO 23601, with minor differences in specific requirements.

Does ISO 23601 require photoluminescent plans?

ISO 23601 does not strictly mandate photoluminescent evacuation plans, but it recommends that plans remain visible during emergency conditions, including power failures. Photoluminescent materials achieve this by absorbing ambient light and emitting visible light in darkness. Many national building codes and fire safety regulations do require photoluminescent evacuation plans, particularly in commercial and high-occupancy buildings. Checking local regulations is essential.

How many evacuation plans does a building need?

ISO 23601 does not specify an exact number. The standard requires plans to be posted at locations where occupants are most likely to need evacuation guidance, including main entrances, exits, lift lobbies, stairwell entrances, corridor junctions, and individual occupancy rooms (hotel rooms, hospital rooms). The number of plans depends on the building size, complexity, and the number of decision points along escape routes. A typical office floor might require four to eight plans; a hotel floor might require one per room plus several in corridors.

Can evacuation plans be displayed digitally instead of printed?

ISO 23601 was written primarily for physical wall-mounted plans. Digital displays can supplement printed plans but should not be relied upon as the sole means of displaying evacuation information, because digital screens depend on power and may fail during the emergencies when evacuation plans are most needed. Where digital displays are used, they should follow the same design principles as ISO 23601 printed plans.

How often must evacuation plans be reviewed?

ISO 23601 requires plans to be updated whenever a change occurs that affects plan accuracy. In addition, plans should be reviewed at regular intervals even if no changes are apparent. A common review interval is annually, aligned with fire risk assessments. Some national regulations specify minimum review frequencies. Each plan should carry a revision number and date so that building management can verify currency.

Next Steps

To create or update evacuation plans in accordance with ISO 23601, start by reviewing the current building layout and verifying that all escape routes, emergency exits, and fire equipment locations are accurately documented. Obtain the current digital floorplan or create one from as-built drawings. Apply ISO 23601 design rules: green escape routes, ISO 7010 symbols, heads-up orientation, and the "You are here" marker at each mounting location.

For teams that need to produce compliant evacuation plans at scale, EvacPlan Generator automates ISO 23601-compliant plan creation directly from uploaded floorplans — built by Wayfinders, the same team behind Plotstuff.

For further reading on the standards that support ISO 23601 implementation, consult:

• •ISO 7010: Safety Signs and Symbols for the safety symbol vocabulary used on evacuation plans.
• •ISO 3864: Safety Colours and Visual Communication for the colour and design framework underlying evacuation plan colour coding.
• •Evacuation Route Planning for the fire engineering and operational aspects of determining escape routes.
• •Fire Compartmentation for understanding how compartmentation interacts with evacuation routes and plan design.