This elevation diagram above and the source appendix below shows 30 countries and their respective building codes with regard to the maximum allowable building height with a single stair for residential occupancies.

Canada is the most restrictive jurisdiction.

International Fire Death Rate statistics show no correlation between the allowable building height for residential buildings with a single egress stair and fatality rates. The U.S. NFPA attributes the worldwide trend in decreased fatality rates between 1979 and 2007 to improved in firefighting capacities, stringent regulation of combustible materials in construction and increased requirements for modern fire safety measures like sprinklering and automatic fire alarm systems.
Fire Death Rate Trends, An International Perspective. (2011). U.S. Fire Administration National Fire Data Center.

Maximum Allowable Building Height with Single Egress Stair for Residential Occupancies
Additional Information

2 Storeys
The NBC does not permit a single means of egress for buildings of more than 2 storeys, except for townhomes of up to three storeys accessed directly from the exterior.

NBC 2015 Minimum Number of Exits Egress from Dwelling Units

United States (IBC)
4 Storeys
The US model building code is the International Building Code, which permits a single exit for R-2 residential occupanices up to 4 stories, with a max. of 4 dwelling units per floor. The building must also "be equipped throughout with an automatic sprinkler system."

Individual cities have established their own regulations, the City of Seattle allows  up to 6 storeys with a single exit. See Seattle Jurisdiction for more information.

United Kindgom
No limit
The UK does not have a height limit for single stair residential buildings. Section 2.6 of the code establishes an occupancy load limit of 60 people per storey and maximum travel distances in Table 2.1. Office buildings can have a single exit stair up to a floor height of 11m (Section 3.3).

Note: Approved Document B, Volume 1 (dwellings) applies only for residential occupancies with habitable storeys with a floor level above ground of up to 18m. Volume 2 (Buildings other than dwellings) applies for residential occupancies exceeding a building height of 18m.

See London Jurisdiction for further information.
Building Regulations 2010 - Fire safety: Approved Document B (2020). Volume 2.

Verified by Karl Wallasch
Chartered Enginer, Trigon Fire
Dipl.-Ing. CEng MIFireE

Germany has a federal system in which each individual state determines their own building code. This table references the model high-rise building code prepared by the “Bauministerkonferenz” (assembly of construction ministers) tasked with establishing the model code referenced by the individual 16 states within Germany. Buildings over 22m with a single exit stair require additional fire safety measures including the fire separation and pressurization of the single exit stair as fire safety stair (Sicherheitstreppenraum) and assembly fire ratings of at least 120 minutes. An additional firefighting elevator is typically required for buildings over 30m in height.

Muster-Richtlinie über den Bau und Betrieb von Hochhäusern Muster-Hochhaus-Richtlinie - MHHR 2008
(Model High-rise Building Code) 

Verified by Boris Stock
Dipl. Ing (FH), BFT Cognos

Maximum of 900m2 floor area per storey, sprinklering not typically required.

Buildings considered high-rise construction “IGH” (immeuble de grande hauteur) require a second egress and additional fire safety measures. For residential occupancies buildings of more than 50m in height are IGH, for all other occupancies 28m in height applies.

Code de la construction et de l'habitation - R122.2 and R122.9

The number of stairs is determined by the building occupancy type and maximum floor area per storey. Table A of the Norme di sicurezza antincendi per gli edifici di civile abitazione (Fire Safety Standards in Residential Buildings) limits the maximum floor area per storey to 500m2 up to a building height of 80m. Buildings above 80m in height require two stairs and helicopter rescue pad on the roof. Further provisions for compartmentalization, elevator construction and fire ratings are required depending on building height between type a (12m to 24m), type b (24m to 32m), type c (32m to 54m), type d (54m to 80m), and type e (above 80m).

Additional requirements apply for buildings over 22m (pressurization and separation of the exit stair).

Total occupancy of the building does not exceed 500 people, the stair must also be of protected construction for evacuation heights exceeding 14m. (See Table 5.1, pg. 46)


25m or residential buildings with a height of over 9 above-ground storeys inclusive.
Warunki techniczne
Dział VI. Rozdział 4. (Sec. VI, Chapter 4) - § 246. 1.

The building code is subdivided by low-rise (under 10m), midrise (10m to 25m) and highrise (over 25m) building heights. For mid-rise buildings, one exit is permitted if the users have a facade opening, accessible to the ladder vehicles of the fire brigade or if no such opening exists, a balcony which the ladders of the fire brigade can reach. The balcony with a sufficiently large surface to evacuate the users of the compartment, has a floor fire rating of REI 60 and a facade element fire rating of E 60 or a handrail set back 1 m from the facade. The occupancy is no more than 50 people. 

5 Storeys (12.5m Finish Floor Level)
The second and third paragraphs shall not apply if the route passes through a stairwell, where the exits of the residential functions depending on such route are directly adjacent to the stairwell, and such route is exclusively used by residential functions and ancillary functions thereof, and the exit of the stairwell directly adjoins the adjacent grounds, and: b) the total usable area of the residential functions depending on the route does not exceed 800m2, none of the floors of any staying area of such residential functions is higher than 12.5m above the terrain height, and none of such residential functions has a usable area exceeding 150m2

4 Storeys
Equivalent to 10m, measured as the finish floor elevation of the highest storey and restricted to an occupancy load of 50 persons
Building Regulations 2006
Technical Guidance Document B - Fire Safety (reprinted 2020) Single Escape Route
1.3.3 Single Escape Stairways

Chapter 4 - Special Regulations According to Building Use Classes - Article 48.5 - a) In residences with a building height below 21.50 m, unprotected normal stairs are considered as escape routes and a second exit is not sought.

Dwelling units in use category 4, where the risk of fire spreading from a dwelling unit to another is limited, can be arranged so that there is only direct access to one escape staircase. There must be direct access from the accommodation unit to the escape staircase (no corridor separation allowed). There can be a maximum of 4 housing units on each floor sharing access to the same escape staircase, see Figure 2.3.3.

For buildings with floors on the top floor more than 22 m above ground or where the rescue openings cannot be reached with the ladders of the emergency services, stairs must be made as security stairs. All dwelling units having direct access to the security stairs via a common anteroom, there can be a maximum of 6 dwelling units per floor.

The conditions above are prescriptive, pre-approved conditions. Buildings over 45m in height require an alternative solutions process and fire engineering consultation to verify performative compliance.

8 Storeys
Fire cells in buildings in risk class 4 with up to 8 floors may have access to one stairwell designed as an escape route. This presupposes that each housing unit has at least one window or balcony that is accessible for rescue and firefighting efforts, cf. § 11-17.

16 Storeys
If the conditions for satisfactory evacuation are in place, stairway Tr2 must be the only escape route in the premises in occupancy class 1 (office) buildings with a maximum of eight storeys and from dwellings in occupancy class 3 (multi-unit residential in buildings with a maximum of sixteen storeys. (BFS 2011:26).

In a building of more than eight but not more than sixteen storeys, each dwelling and premises shall be designed to have access to at least one Tr2 stairway. In a building with more than sixteen storeys, each dwelling and premises shall be designed to have access to at least one Tr1 stairway. (BFS 2011:26).

See Section 5:425 and 5:426 for Stairway type Tr1 and Tr2 fire safety and design provisions.

South Korea
No Limit
South Korea is similar to the United Kingdom in that it does not establish a maximum building height with a single exit stair in apartment buildings. Rather the code limits single exit stair conditions based on a maximum inhabitabed floor area of 300m2 per storey or less than four dwelling units per floor. Article 35 of the code also requires the exit stair to be a firefighting stair (special evacuation stair) for apartment buildings of 16 or more storeys.
건축법 시행령
제34조(직통계단의 설치)

Korean Building Code
Chapter 5: Section 34

5 Storeys
One exit stair is permitted for non-combustible construction with a floor area per storey up to 200m2 and for combustible construction with a floor area per storey up to 100m2. This applies for apartment buildings as well as hotels, boarding houses, dormitories and ryokans (traditional japanese inn).
Building Application Memo 2020

Verified by Luis Oliveira
Tezuka Architects, Tokyo, Japan

18 Storeys
Two means of egress is required if the floor area per storey exceeds 650m2 or the travel distance between the dwelling unit door to the nearest exit exceeds 15m, between 10 and 18 storeys the same floor area limitation applies with a maximum travel distance of 10m.
GB 50368-2005
Residential Building Code
Section 9.5.1

“4.6.2 - All buildings, which are 15 m in height or above, and all buildings used as educational, assembly, institutional, industrial, storage, and hazardous occupancies and mixed occupancies with any of the aforesaid occupancies, having area more than 500 m2 on each floor shall have a minimum of two staircases. They shall be of enclosed type; at least one of them shall be on external walls of buildings and shall open directly to the exterior, interior open space or to an open place of safety. Further, the provision or otherwise of alternative staircases shall be subject to the requirements of travel distance being complied with.”

Sprinklering and pressurization also only required if above 25m in building height.
NCC 2015 Building Code of Australia - D1.2 Number of exits required (pg 158)

New Zealand
10m if unsprinklered, 25m if sprinklered. Maximum occupant load of 50 per floor.

6 Storeys “every building which exceeds 6 storeys in height or in which the level of the floor of the uppermost storey is more than 17m above the level of the ground at the point of discharge of the main staircase shall, in addition to the main staircase, be provided with a second staircase as means of escape in case of emergency.”

South Africa
3 Storeys
SANS 10400-T: Fire Protection
4.16.2 (d) Provision of escape routes

Buildings up to 13m in height can have a single unprotected stair. The code also sets a maximum travel distance of 30m to the exit stair. Buildings exceeding 13m in height may have a single protected stair if residential use, or any use not exceeding a maximum occupancy load of 30 people per floor.  All buildings regardless of occupancy exceeding 29m in building height require two stairs, one of which may be an exterior stair.

תקנות התכנון והבניה
פרק ז': בניין גבוה ורב-קומות
חדר מדרגות מוגן ומדרגות חוץ בבניין גבוה תק' (מס' 3)  תשס"ח-2008

Planning and Building Regulations, Chapter 7: A tall, high-rise building - Protected staircase and exterior stairs in a high-rise building, (No. 3), 2008

United Arab Emirates
Maximum four dwelling units per floor and a maximum total floor area per storey of 500m2.
UAE Fire & Life Safety Code of Practice - Chapter 3: Means of Egress - 12.1.3 Single Exit Staircase
6 Storeys
3-1-10-2-4 - In the following cases, each residential unit can exceptionally access only one exit. A single exit is allowed for buildings up to 23m in height with maximum 2 dwelling units per floor, in which the stair must be fire rated. Note: the fire regulations were amended in 2019 to permit a maximum height of 30m, or 6 storeys above ground, in which the stair must be ventilated, the building sprinklered, and a maximum of 3 dweeling units per floor.
مقررات ملّی ساختمان ایران / مبحث سوم
حفاظت ساختمانها در مقابل حریق
National Building Regulations of Iran (2017) - Chapter 3 - Fire Protection of Buildings

Saudi Arabia
3 Storeys 8.18.2 (c) - “Buildings classified as Group R-2 equipped throughout with an automatic sprinkler system in accordance with Section 7.3 of SBC 801 and provided with emergency escape and rescue openings in accordance with Section 8.25 shall have a maximum height of three stories above grade, or as agreed by the local municipality.”
Saudi Building Code 2007
Chapter 8 - Means of Egress
Table 8.18.2 Buildings with One Exit

Note: Some jurisdictions have made their building codes available in English.Otherwise translations have been provided by a native speaker or local architect. For verification the jurisdiction source codes should be consulted.

Additional Information:

Dreiman, E. (2020). Ground Ladder Basics. International Society of Fire Service Instructors. https://www.isfsi.org/blog/ground-ladder-basics

U.S. Fire Administration National Fire Data Center. (2011). Fire Death Rate Trends: An International Perspective. FEMA, Topical Fire Report Series, Vol 12, Issue 8.

Winberg, D. (2016). International Fire Death Rate Trends. SP Technical Research Institute of Sweden.

Statistics Canada. (2017). Fire statistics in Canada, Selected Observations from the National Fire Information Database 2005 to 2014.

Clare, J. and Kelly, H. (2017).  Fire and at risk populations in Canada -  Analysis of the Canadian National Fire Information Database.