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Evacuation Route Planning: How to Design and Maintain Escape Paths

Evacuation route planning is the discipline of designing, documenting, and maintaining the paths by which building occupants can reach a place of safety during an emergency. It sits at the intersection of architectural design, fire engineering, regulatory compliance, and operational management. A well-designed evacuation system considers travel distances, exit capacities, route protection, signage, emergency lighting, and the needs of persons with mobility or sensory impairments. A poorly designed or poorly maintained system costs lives. This guide provides a practical framework covering the UK regulatory requirements, the engineering principles behind route design, and the operational processes needed to maintain evacuation routes as effective, auditable safety systems — with specific attention to how floorplan-based digital tools transform what has traditionally been a static, paper-based exercise.

Table of Contents

What Is Evacuation Route Planning

Evacuation route planning is the systematic process of identifying, designing, and maintaining the paths that building occupants will use to move from their location within a building to a place of safety outside the building (or to a place of relative safety within the building, in the case of phased or progressive horizontal evacuation strategies). An evacuation route encompasses every element that an occupant encounters during the journey: the room they start in, the door they pass through, the corridor or stairway they traverse, the final exit door, and the external path to the assembly point.

Effective evacuation route planning requires consideration of multiple interdependent factors: the maximum number of people who may need to use the route simultaneously (occupant capacity), the physical dimensions of the route (width, headroom, gradient), the distance from the furthest occupied point to the nearest exit (travel distance), the protection afforded to the route against fire and smoke (fire-rated construction, door ratings, smoke ventilation), the signage and emergency lighting that guide occupants along the route (covered in our Emergency Lighting Testing guide), and the accessibility of the route for persons with disabilities.

Regulatory Framework

In England and Wales, evacuation route design in new buildings and major refurbishments is governed by the Building Regulations 2010, specifically:

Approved Document B (Fire Safety) — Volume 1 covers dwellings and Volume 2 covers buildings other than dwellings. Approved Document B provides prescriptive guidance on travel distances, exit widths, the number of escape routes required, protection of escape routes, and the provision of fire safety features such as emergency lighting and fire doors. Compliance with Approved Document B is not mandatory — it represents one way of satisfying the functional requirements of the Building Regulations — but departure from its guidance requires justification through fire engineering analysis.

BS 9999:2017 — Code of practice for fire safety in the design, management, and use of buildings. BS 9999 provides a more flexible, risk-based framework for fire safety design compared to Approved Document B. It introduces risk profiles (occupancy characteristics combined with fire growth rate assumptions) that determine the appropriate design parameters for travel distances, exit widths, and other escape provisions.

The Regulatory Reform (Fire Safety) Order 2005 — While primarily concerned with the ongoing management of fire safety in occupied premises (rather than building design), the Fire Safety Order requires the responsible person to ensure that adequate means of escape are maintained. This includes keeping escape routes clear, maintaining fire doors and emergency lighting along escape routes, and reviewing the adequacy of escape provisions when the building use or occupancy changes.

BS 9991:2015 — Specific guidance for the fire safety of residential buildings, covering flat-to-common-area relationships, stay-put versus simultaneous evacuation strategies, and the impact of building height on evacuation design.

The Building Safety Act 2022 — For higher-risk buildings, introduces additional requirements for escape route management as part of the broader safety case approach.

Ireland

In the Republic of Ireland, evacuation route design is governed by Technical Guidance Document B (TGD B) supporting Part B of the Building Regulations. TGD B sets out prescriptive requirements for means of escape, including travel distance limits, exit widths, and the protection of escape routes, closely aligned with the UK's Approved Document B. The Fire Services Acts 1981 and 2003 require the person having control of premises to ensure the safety of persons in the event of fire, which includes maintaining adequate means of escape. IS 3217 (emergency lighting) and IS 3218 (fire detection and alarm systems) provide the technical standards for the active systems that support evacuation.

United States

In the United States, evacuation route design is primarily governed by NFPA 101: Life Safety Code and the International Building Code (IBC). NFPA 101 specifies maximum travel distances of 200 feet (61 metres) for sprinklered buildings and 150 feet (46 metres) for non-sprinklered buildings in most occupancy types, with dead-end corridor limits of 50 feet (15 metres) for sprinklered buildings and 20 feet (6 metres) for non-sprinklered. The IBC provides similar requirements with occupancy-specific variations. ADA (Americans with Disabilities Act) requirements mandate accessible means of egress, including areas of rescue assistance equivalent to the UK refuge area concept.

Travel Distance Limits

Travel distance is the actual distance that a person must walk from their location to the nearest available exit, measured along the centre line of the route they would follow. It is not a straight-line measurement — it follows corridors, passes through doorways, and accounts for any obstacles that define the walking path.

The maximum permissible travel distance depends on the risk profile of the building and whether the occupant has a choice of escape direction:

Approved Document B Limits (Buildings Other Than Dwellings)

| Risk Profile | One Direction Only (Dead End) | More Than One Direction |

|---|---|---|

| Low risk (offices, residential common areas) | 18 metres | 45 metres |

| Normal risk (shops, commercial, assembly) | 18 metres | 45 metres |

| Higher risk (storage, industrial) | 12 metres | 25 metres |

BS 9999 Limits (Risk-Profile Based)

BS 9999 adjusts travel distance limits based on the combination of occupancy characteristic and fire growth rate:

| Profile Group | One Direction (m) | More Than One Direction (m) |

|---|---|---|

| A1 (low fire growth, able-bodied, awake, familiar) | 18 | 45 |

| A2 | 18 | 45 |

| B1 | 18 | 35 |

| B2 | 14 | 26 |

| C1 (high fire growth, mobility-impaired, sleeping) | 9 | 18 |

| C2 | 9 | 18 |

These limits represent maximum distances that should not be exceeded. In practice, the actual travel distances achieved in a building should be verified by measurement on the floorplan and, for complex layouts, by walking the routes on site.

Travel distance measurement must start from the furthest point within any room or space where a person could reasonably be located. For open-plan offices, this is typically the furthest desk position. For assembly spaces, it is the furthest seat. For storage areas, it is the furthest aisle position.

Exit Width Calculations

Exit width determines the flow capacity of an escape route — the number of people who can pass through the exit in a given time. Inadequate exit width creates bottlenecks that delay evacuation and can lead to crushing in extreme cases.

The minimum exit width for any escape route is 750mm (sufficient for one person at a time). For routes serving more than a handful of occupants, the required width is calculated based on the number of people who will use the exit:

Basic calculation method (Approved Document B):

  • •Exits serving up to 60 persons: minimum 750mm clear width.
  • •Exits serving 60 to 110 persons: minimum 850mm clear width.
  • •Exits serving more than 110 persons: minimum 1050mm clear width, plus an additional 75mm for every additional 15 persons above 110.

Flow rate method (BS 9999):

  • •The exit width is calculated based on a flow rate of 40 persons per minute per 520mm unit of exit width for level routes, and 30 persons per minute for stairways.
  • •The required width = (number of persons x evacuation time factor) / (flow rate x available evacuation time).

When a building has multiple exits, the calculation should assume that the largest single exit is unavailable (discounted), and the remaining exits must have sufficient combined width to accommodate the total occupant capacity. This "minus one" rule ensures that the loss of one exit (due to fire blocking it) does not prevent safe evacuation.

Exit width must be maintained clear of obstructions at all times. Furniture, stored goods, display stands, and temporary structures must not reduce the effective width below the calculated requirement. This is an ongoing operational requirement, not merely a design consideration.

Dead-End Restrictions

A dead-end condition exists where an occupant can only travel in one direction to reach an escape route or exit. Dead ends represent the highest-risk escape condition because the single available route may be blocked by fire, leaving the occupant trapped.

Approved Document B and BS 9999 both restrict dead-end travel distances to the shorter limits shown in the travel distance tables above. Additional requirements apply:

  • •Dead-end corridors should not serve sleeping accommodation unless additional protective measures (sprinklers, enhanced detection) are provided.
  • •The dead-end portion of a corridor should be separated from the remainder of the escape route by fire doors to prevent smoke from the dead end contaminating the continuing escape route.
  • •In buildings designed under BS 9999, the acceptability of dead ends is assessed in the context of the overall risk profile, and longer dead ends may be acceptable where compensating features (early warning, sprinklers, smoke control) are present.

Identifying dead-end conditions requires spatial analysis of the building layout. On a two-dimensional floorplan, dead ends are visually apparent — corridors or sections with only one exit direction. Plotstuff and similar modern spatial infrastructure software tools can highlight dead-end conditions on uploaded floorplans, enabling designers and fire risk assessors to identify and address these high-risk configurations.

Protected Routes and Corridors

An escape route is "protected" when it is enclosed by fire-resisting construction (walls, floors, ceilings) with fire-rated doors, providing a degree of separation from the rest of the building. Protection is essential for routes that serve as the final stage of escape — particularly stairways in multi-storey buildings.

The levels of route protection specified in Approved Document B and BS 9999 include:

  • •Protected corridor — A corridor enclosed by fire-resisting construction with FD20S or FD30S fire doors (see Fire Door Inspection for maintenance requirements). Required where the corridor forms part of an escape route and rooms opening onto it present a fire risk.
  • •Protected stairway — A stairway enclosed by fire-resisting construction, typically to the full period of the building's structural fire resistance (30, 60, or 120 minutes depending on building height and purpose group). All doors to a protected stairway must be fire-rated and self-closing.
  • •Protected lobby — An intermediate space between the corridor and the stairway, providing additional separation between the general circulation space and the stairway. Required in certain building types and heights, particularly residential buildings over 11 metres in height.
  • •Firefighting lobby — A ventilated lobby adjacent to a firefighting stairway, designed for fire service access. Required in buildings over 18 metres in height.

The fire resistance of these protected elements must be maintained throughout the building's life. Penetrations (service pipes, cables, ducts) through fire-resisting walls and floors must be properly fire-stopped, and any breaches identified during inspections must be remediated. This is directly linked to the building's fire compartmentation integrity.

Assembly Point Requirements

An assembly point is the designated location outside the building where evacuated occupants gather to be accounted for. The assembly point must satisfy several practical requirements:

  • •Distance from the building — Far enough that falling debris, radiant heat, and smoke do not endanger those assembled. As a general guideline, at least 20 metres from the building, though the appropriate distance depends on the building's height and construction.
  • •Capacity — Large enough to accommodate the full building population without crowding onto roadways or obstructing emergency vehicle access.
  • •Accessibility — Reachable by all building occupants, including those with mobility impairments, via routes that are paved, level or ramped, and free from significant trip hazards.
  • •Signage — Clearly marked with assembly point signs compliant with ISO 7010 (sign reference E007).
  • •Separation from emergency vehicle routes — The assembly point must not obstruct the access routes used by fire appliances and ambulances.

The location of the assembly point should be shown on the building's evacuation plans and communicated to all occupants during induction and fire drill briefings.

Evacuation Plan Design to ISO 23601

Evacuation plans — the physical or digital maps displayed within buildings showing escape routes and safety equipment — should be designed in accordance with ISO 23601, which specifies the layout, content, and safety signs used on evacuation and escape plans. Key requirements include:

  • •Orientation — The plan must be oriented to match the viewer's perspective ("heads-up" orientation). A plan on the north wall of a building should show north at the top; a plan on the south wall should show south at the top. This principle ensures that occupants can immediately relate the plan to their surroundings.
  • •Content — The plan must show the building layout, all available escape routes, the locations of fire safety equipment (call points, extinguishers, first-aid kits), the "You are here" indicator, exit doors, assembly point locations, and relevant safety rules.
  • •Signs and symbols — Must comply with ISO 7010 safety sign standards.
  • •Colour coding — Green for escape routes and exits, red for firefighting equipment, blue for first-aid equipment.
  • •Scale and legibility — The plan must be legible from the normal viewing distance (typically 1 metre for wall-mounted plans). Text must be in the building's operational language(s).

Generating ISO 23601-compliant evacuation plans manually for a multi-storey building is labour-intensive and error-prone, particularly when the plans must be updated following building modifications. Modern spatial infrastructure software like Plotstuff can generate these plans directly from the floorplan data, ensuring consistency with the underlying asset register and escape route definitions.

Route Maintenance and Obstruction Monitoring

Designing an effective evacuation route is necessary but not sufficient. The route must be maintained in a usable condition throughout the building's operational life. Common maintenance issues include:

  • •Obstructions — Storage, furniture, deliveries, cleaning equipment, and temporary structures placed in corridors, stairways, or in front of exit doors. Regular inspections — at least weekly — should verify that all escape routes are clear.
  • •Locked exits — Exit doors that are locked, bolted, or otherwise secured in a way that prevents immediate use during an emergency. All doors on escape routes must be openable without a key from the escape side. Panic hardware (push bars or push pads) should be fitted to final exit doors serving more than 60 persons.
  • •Fire door failures — Fire doors on escape routes that are propped open, have defective closers, or have damaged seals compromise the route's protection. See Fire Door Inspection for the inspection regime.
  • •Emergency lighting failures — Luminaires on escape routes that have failed or whose batteries are exhausted render the route unusable during a mains failure. See Emergency Lighting Testing for the testing protocol.
  • •Signage damage or obstruction — Exit signs that are obscured by decorations, advertising, or building modifications, or that have failed (illuminated signs with dead lamps).
  • •Structural changes — Building modifications that alter the route geometry (new partitions, removed doors, relocated walls) may invalidate the original escape route design and require a formal review.

A floorplan-based monitoring system enables obstruction reporting and resolution tracking by providing spatial context. An obstruction reported at a specific location on the floorplan can be prioritised based on its impact on the escape route — an obstruction blocking the only exit from a dead-end corridor is more critical than one in a corridor with multiple alternative routes.

Fire Drill Planning

Fire drills are the operational test of the evacuation system. They verify that occupants know the evacuation procedure, that the routes are passable, that the fire wardens and marshals perform their roles effectively, and that the assembly point can accommodate the building population.

Effective drill planning includes:

  • •Frequency — The Fire Safety Order does not specify a mandatory drill frequency, but best practice guidance recommends at least two drills per year for most premises, with more frequent drills for higher-risk buildings (care homes, hospitals, schools).
  • •Scenarios — Vary the scenarios between drills: block a primary exit to test alternative route usage, conduct a drill during different times of day or shift patterns, simulate a phased evacuation in buildings that use progressive horizontal evacuation.
  • •Observation and timing — Appoint drill observers to monitor occupant behaviour, identify bottlenecks, and record evacuation times. Record the time from alarm activation to the last person reaching the assembly point.
  • •Debriefing — Conduct a post-drill debrief with fire wardens and building management to identify issues: occupants who did not respond to the alarm, routes that were congested, fire doors that were found propped open, emergency lighting that was not functioning, assembly point confusion.
  • •Record keeping — Document the date, time, scenario, number of occupants evacuated, total evacuation time, issues observed, and corrective actions identified. These records form part of the fire safety management file.

PEEP and GEEP Requirements

The Equality Act 2010 and the Fire Safety Order together require that evacuation provisions accommodate persons with disabilities. This is addressed through:

Personal Emergency Evacuation Plan (PEEP) — An individualised plan developed for a specific person whose disability, impairment, or medical condition means they cannot independently use the standard evacuation routes. The PEEP identifies the person's specific needs (e.g., cannot use stairs, cannot hear the alarm, requires assistance to move), the assistance they will receive (nominated assistants, evacuation chairs, refuge areas), and the route they will take.

General Emergency Evacuation Plan (GEEP) — A generic plan that covers visitors, contractors, and other persons whose individual needs are not known in advance. The GEEP identifies the building's evacuation provisions for persons with disabilities (refuge areas, evacuation lifts, alternative routes) and the procedures for providing assistance.

Key considerations for accessible evacuation include:

  • •Refuge areas — Designated fire-protected areas (typically on each floor adjacent to a protected stairway) where persons who cannot use stairs can wait for assistance from the fire service or trained evacuation assistants. Refuge areas must be clearly signed, equipped with a communication device (typically a fire telephone or intercom), and integrated into the fire service's operational plan for the building.
  • •Evacuation lifts — In some buildings, lifts that are designed and maintained for use during fire evacuation (with enhanced fire protection, independent power supply, and fire service override) may be provided as an alternative to carry-down by stairway.
  • •Evacuation chairs — Specialist devices for descending stairways with a seated occupant. Trained operators must be available during occupied hours.
  • •Visual and tactile alarm devices — For persons with hearing impairments, supplementary alarm devices (flashing beacons, vibrating pagers) may be required.
  • •Wayfinding and signage — Evacuation signage must be designed with accessibility in mind, including tactile and braille components where appropriate, and positioned at heights accessible to wheelchair users.

PEEPs and GEEPs should be reviewed whenever the building layout changes, evacuation routes are modified, or the individual's circumstances change. Recording the spatial elements of PEEPs — refuge area locations, designated routes, evacuation equipment locations — on the building floorplan provides clarity for both the plan holder and their nominated assistants.

Digital Route Mapping on Floorplans

Digital route mapping transforms evacuation route planning from a static design exercise into a living, maintainable compliance system:

  • •Route definition — Draw escape routes directly on the floorplan, specifying route widths, travel distances (automatically calculated), and protection levels. The system verifies that travel distances do not exceed the applicable limits and flags any exceedances.
  • •Capacity analysis — Input occupant numbers for each room and space, and the system calculates exit width requirements and identifies any exits that are under-dimensioned for their served population.
  • •Dead-end identification — The system's spatial analysis identifies dead-end conditions and measures dead-end travel distances against the applicable limits.
  • •Asset integration — Emergency lighting, fire doors, exit signs, and fire alarm call points along escape routes are shown as part of the route's infrastructure, linking evacuation route management with fire safety asset management.
  • •Evacuation plan generation — ISO 23601-compliant evacuation plans can be generated directly from the floorplan data, with correct orientation, safety signs, and route highlighting, and automatically updated when the underlying data changes.
  • •Change management — When building modifications are proposed, the impact on evacuation routes can be assessed by modifying the digital floorplan and re-running travel distance and capacity analyses before the physical changes are made.

Key Takeaways

  • •Evacuation route planning requires integrated consideration of travel distances, exit widths, dead-end restrictions, route protection, signage, emergency lighting, and accessibility — all governed by Building Regulations Part B, BS 9999, and the Fire Safety Order.
  • •Travel distance limits range from 9 to 45 metres depending on risk profile and whether alternative directions of escape are available, with dead-end conditions always subject to the most restrictive limits.
  • •Exit width calculations must account for the discounting of the largest single exit, ensuring that evacuation capacity is maintained even when one exit is blocked.
  • •Assembly points must be appropriately located, sized, signed, and accessible, with their positions communicated through ISO 23601-compliant evacuation plans.
  • •PEEPs and GEEPs are legal requirements for ensuring that persons with disabilities can evacuate safely, supported by refuge areas, evacuation equipment, and trained assistance.
  • •Digital route mapping on floorplans enables automated travel distance verification, capacity analysis, dead-end identification, and evacuation plan generation — replacing manual measurement and static documentation.

Frequently Asked Questions

How often should evacuation plans be updated?

Evacuation plans should be reviewed and updated whenever the building layout changes (walls added or removed, exits modified, use of spaces changed), whenever the fire risk assessment is revised, and at least annually as part of the routine fire safety management review. Plans displayed in the building must be replaced with updated versions whenever the content changes.

What is the maximum travel distance in an office building?

Under Approved Document B, the maximum travel distance in an office building (normal risk) is 18 metres in one direction only (dead end) and 45 metres where more than one direction of travel is available. BS 9999 provides similar limits for the equivalent risk profiles (A1/A2) but may allow different limits depending on the specific fire growth rate and occupant characteristics assessed.

Do I need an assembly point for a small building?

Yes. Every building should have a designated assembly point, regardless of size. For very small buildings, the assembly point may simply be the pavement on the opposite side of the road, but it must be defined, communicated to occupants, and used during drills. Without a defined assembly point, there is no mechanism for accounting for all occupants after evacuation.

What is the difference between simultaneous and phased evacuation?

Simultaneous evacuation means all occupants leave the building at the same time when the alarm sounds. Phased evacuation means occupants on the fire floor evacuate first, followed by adjacent floors, with other floors remaining in place until called to evacuate. Phased evacuation is used in tall buildings where simultaneous evacuation would overwhelm the stairway capacity. The building's fire strategy must specify which approach applies.

How do I accommodate wheelchair users in evacuation planning?

Wheelchair users who cannot use stairs should be directed to designated refuge areas — fire-protected spaces adjacent to stairways where they can wait for assisted evacuation by the fire service or trained staff using evacuation chairs or lifts. Each wheelchair user in the building should have a PEEP that specifies the refuge area, the nominated assistants, and the communication arrangements. The refuge areas, evacuation equipment locations, and designated routes should be mapped on the building floorplan.

Next Steps

Audit your current evacuation routes by measuring travel distances on your building floorplans, verifying exit widths against calculated occupant loads, and identifying any dead-end conditions. Review your evacuation plans for ISO 23601 compliance and ensure that PEEPs are in place for all occupants who require them. Transition from manual measurement and paper-based plans to a floorplan-based digital system that automates distance calculations, generates compliant evacuation plans, and integrates with your broader fire safety asset management programme.

If you need to produce ISO 23601-compliant evacuation plans quickly, EvacPlan Generator — built by Wayfinders, the team behind Plotstuff — automates compliant plan generation directly from uploaded floorplans.

For related guidance, see our articles on ISO 23601 Evacuation Plan Standard, ISO 7010 Safety Signs, and Emergency Lighting Testing.

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