Jurisdictions

Cite this image:

Speckert, C. (2022). Jurisdictions: Maximum Permitted Height for Single Stair Buildings [Infographic]. McGill School of Architecture. Retrieved from https://secondegress.ca/Jurisdictions

Maximum Building Height
Explanation of code interpretation and additional information regarding relevant restrictions to maximum floor area, occupancy load, travel distance, etc.

Note: Some jurisdictions have published a translation of their building code in English. Otherwise translations have been provided by a native speaker, Google Translation or have been interpreted via correspondence with a local architect. Please refer to the original source documents for clarification and updated information.

United States (IBC)

3 Storeys
The US model building code permits single exits in apartment buildings (R-2 occupancy) of not more than three storeys in building height, with a maximum of 4 dwelling units per storey. The building must be sprinklered throughout (NFPA 13-R).

Each state and some cities have their own building codes, New York City, the City of Seattle and State of Hawaii (Honlulul) allow for single exit conditions in buildings of up to 6 storeys with a single exit.

Seattle Building Code 2018 - Chapter 10: Means of Egress
Section 1006.3.3 Single exits

NYC Building Code 2014 - Chapter 10 Means of Egress (amended IBC 2009)
Section 1021.1 Single Exits

5. Buildings of Group R-2 occupancy of construction Type I or II not exceeding six stories and not exceeding 2,000 square feet (186 m2) per story. 

Hawaii State Building Code 2018 (amended IBC 2012)  

6 storeys
Mexico City specifies that in medium and high fire risk buildings, the number of evacuation routes from any level must be a minimum of two.

Table 4.5-B establishes the building height at which residential buildings are deemed low, medium and high risk. Buildings exclusively for residential use are classified as low risk up to six storeys in building height. Where the building includes other uses, the risk classification of the other use prevails.

Brazil

80m (São Paulo) / 25 storeys (Rio de Janeiro)
São Paulo requires two exit staircases for buildings exceeding 36m in height, except that apartment buildings (Division A-2 occupancies) up to 80m in building height are permitted to be provided with a single exit staircase.

“5.5.3.5 Nas edificações com altura acima de 36 m, independente do item 5.5.3.1, é obrigatória a quantidade mínima de duas escadas, exceto para a Divisão A-2. Nas edificações da Divisão A-2, com altura acima de 80 m, independente do item 5.5.3.1, é obrigatória a quantidade mínima de duas escadas.“

Rio de Janeiro requires two exit staircases for apartment buildings (Division A-2 occupancies) of 25 or more storeys in building height.

“5.3.2.2 As edificações com 15 ou mais pavimentos, qualquer que seja a área do pavimento, devem possuir, no mínimo, duas escadas de emergência. Excetua-se as edificações das divisões (A-2, A-6, G-2).

"(D) As edificações das divisões (A-2, A-6, G-2) com 25 ou mais pavimentos, qualquer que seja a área construída, devem possuir no mínimo duas escadas de emergência."

25m
The Building Code of Australia permits one exit for apartment buildings (Class 2 building) of not more than 25m in building height. ‘Fire-isolated’ (corridor separated) exit stairs are required for buildings of more than 3 storeys or 4 storeys where sprinklering or increased fire separation is provided. A maximum dead end travel distance of 6m applies.

25m
The New Zealand Building Code permits one exit for apartment buildings (risk group SM) where the escape height is no greater than 25m if sprinklered, and 10m if unsprinklered. Dead-end limits on travel distance apply.

18m / 30m / No Maximum Height Limit
The United Kingdom does not have a maximum height limit for single stair in multi-unit residential buildings. Section 2.6 of the code establishes an occupancy load limit of 60 people per storey and Table 2.1 determines the maximum travel distance to the single stair. Office buildings can be single stair where the height of the uppermost occupied floor level does not exceed 11m above grade (Section 3.3).

Update (January 2023): In response to the Grenfell Tower inquiry, the Royal Institute of British Architects and London Fire Brigade submitted a request to further study the fire safety of single exit stair high-rise residential buildings. On December 23, 2022 the UK Government announced an open consultation to “introduce a threshold whereby residential buildings above 30 metres in height should be designed and built with 2 staircases.”

Update (July 2023): “The Housing Secretary, Michael Gove, announces that the UK government will require two staircases in all new residential high-rises taller than 18m.”

18m
Following the Grenfell disaster, Scotland reviewed the Building Standards on Fire Safety in Scotland and issued a recommendation for change to the guidance on escape (2.9).

“36. On the need for additional stairways there was no consensus amongst the Review Panel members. However the view of the chair, which was endorsed by all members of the international sub-group, was that there was a need to require at least two stairways in high rise domestic buildings with a storey at a height of 18m. This is firstly to provide an alternative in case of the failure of the first stairway and secondly to provide a route for escape if the other stairway is being used for fire-fighting operations. The height of 18m is currently used with in the Technical Handbooks and it was considered sensible to retain it as it is well known and relates to the ability of the fire service to intervene if absolutely necessary through the use of high reach appliances.”

“Recommendation 5 - Changes are needed to the simple guidance on escape. In particular, in domestic buildings over 18m there should be two stairways and fire service activated evacuation sounders in each flat.“

Building Standards Technical Handbook 2022: Domestic - Table 2.6 Escape routes from flats and maisonettes (including social housing dwellings) and any ancillary rooms
For buildings where the height of the topmost storey is more than 7.5m but not more than 18m above adjacent ground:

At least one escape route and
- protected lobbies (see clause 2.9.13), and
- smoke ventilation (see clause 2.9.14 – 2.9.16), and
- not more than 10m travel distance inside protected lobbies, or
At least two escape route [3] and
- not more than 30m travel distance in protected corridor

4 Storeys
Ireland permits a single escape stairway for apartment buildings where the floor level of the uppermost storey is not more than 10m above ground level, and the occupancy load is not more than 50 people per storey.

16 Storeys
Sweden permits one exit for class 3 (residential) buildings up to 16 storeys with a maximum occupant load of 50 people per storey and a maximum travel distance of 30m. Different requirements for the fire-protection rating/smoke-tightness standard of closures apply for buildings of not more than 8 storeys and buildings of more than 8 but not more than 16 storeys.

45m
Denmark permits a single exit for multi-unit residential (category 4) buildings up to 45m in building height, with a maximum of 4 dwelling units per storey with direct access from the dwelling unit to the exit stair (no corridor separation). For building with floors more than 22m above ground, where the rescue openings cannot be reached by rescue ladder, a pressurized “security” stair with corridor separation is required and a maximum of 6 dwelling units per storey is allowed.

These are prescriptive, pre-approved conditions. According to a local architect, buildings over 45m in height require a performative code-compliance process and fire engineering consultations.

8 Storeys
Norway permits a single exit for multi-unit residential (risk class 4) buildings up to 8 storeys so long as each dwelling unit has an operable window or balcony for rescue and firefighting. A maximum travel distance of 15m from the dwelling unit entry door to the exit stair door applies.

Finland

52m
Finland allows for a single exit for multi-unit residential (’Yleensä‘) buildings up to 52 metres measured to the floor level of the uppermost occupied storey. The single exit staircase must be protected against fire (’Palolta suojattu’) in buildings exceeding 24 metres in height and 300m² in area. A fire sprinkler system is required for buildings exceeding 24 metres in height where a single staircase is provided.

The following graphic is from the unofficial translation. Legally binding versions only in Finnish and Swedish.

50m
France permits a single exit for residential buildings up to 50m in building height. Two means of egress and additional life safety measures are required for high-rise buildings (immeuble de grande hauteur) exceeding this height.

Belgium

25m
The Belgian code is subdivided by low-rise (under 10m), mid-rise (10m to 25m) and high-rise (over 25m) building heights. Belgium allows one exit for mid-rise buildings of not more than 25m in building height with a maximum occupant load of 50 people per fire compartment.

5 Storeys (12.5m Finish Floor Level)
The Netherlands permits one exit for multi-unit residential building where the floor level of the uppermost storey is no more than 12.5m above grade (5 storeys), where the floor area served by the single exit does not exceed 800m², with a maximum floor area per dwelling unit of 150m². The Netherlands also permits one exit for multi-unit residential buildings where the floor level of the uppermost storey is not more than 6m above grade (three storeys) with no more than 6 dwelling units served by the single exit.

Note: correspondence with a Dutch architect indicates that the 5 storey limit can be exceeded by providing a ‘safety escape route’ [Veiligheidsvluchtroute], such an escape route is separated by a non-enclosed exterior gallery to prevent the passage of smoke into a single staircase (see diagram below).

As a recent example, the multi-unit residential building BBSH20A in Amsterdam (completed in 2021), by Olaf Gisper Architects  is a 10 storey mass timber design with 29 dwelling units and a ‘safety escape route’ single exit stair.
https://olafgipser.com/projects/residential-building-bsh/#1 

Germany

60m
Germany permits a single exit for multi-unit residential buildings up to 60m in building height. 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 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.

The model high-rise building code applies to high-rise buildings over 22m in building height and is prepared by the federal “Bauministerkonferenz” (assembly of construction ministers) tasked with establishing the model code referenced by the 16 individual states within Germany.

No Maximum Height Limit
Switzerland permits a single exit for multi-unit residential buildings without a specified maximum building height with a 900m² maximum floor area per storey, a maximum total travel distance of 35m and a maximum occupant load of 100 per floor area. Sprinklering is typically not required.

The association of cantonal fire insurance companies establishes the fire safety regulations across Switzerland.

Austria

32m
Austria permits a single exit for multi-unit residential buildings up to 32m in building height. Maximum travel distances apply. Pressurization of the exit stair is required. The code distinguishes between buildings where the uppermost storey is not more than 32m above ground, between 32m and 90m above ground, and buildings more than 90m above ground.

Poland

25m
Poland permits a single exit for medium-high multi-unit residential (Division ZL IV) buildings up to 25m in building height or of a maximum of 9 storeys above grade. A single exit is also permitted in residential buildings exceeding 25m in building height with additional life safety measures and a maximum floor area per storey of 750m².

Romania

28m
Romania permits a single exit for multi-unit residential buildings of up to 28m in height.

Two exit staircases are required for buildings classified as ‘tall buildings’, defined as having a finished floor level of the entrance floor of the uppermost dwelling unit more than 28 meters above the level of firefighter access.

Italy

80m
Italy permits a single exit for multi-unit residential buildings up to 80m in building height with a maximum floor area per storey of 500m². 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). Buildings above 80m in height require two stairs and helicopter rescue pad on the roof.

28m
Spain permits a single exit for multi-unit residential buildings up to 28m in building height measured as the floor level of the uppermost storey, where the total occupancy load of the building is not more than 500 people. The exit stair must be protected (fire separated) for residential buildings over 14m in building height.

Portugal

60m
Portugal permits a single staircase for apartment buildings of up to 28m in height and for buildings of up to 60m in height with distinct conditions. According to a local architect, buildings over 60m in height are subject to project-specific performance criteria and may lead to designs with two staircases (Article 53 Campo de aplicação).

Single stair designs for buildings up to 28m in height require a maximum travel distance of 15 metres, and buildings over 28m in height require a maximum travel distance of 10 metres and maximum floor area of 500m².

Part III - Buildings not exceeding 28m in height

Article 31 - Number of stairs
“2 - Buildings may be served by a single staircase when the distance between the door of any dwelling and access to the stairwell, or the equivalent space, when there is no well-defined stairwell, does not exceed 15 m; otherwise, the building must be served by more than one staircase.”

Part IV - Buildings taller than 28m

Article 59 - Number of stairs

“2 - Buildings may be served by a single staircase, if the area per floor does not exceed 500m² and the distance to be covered between the door of any dwelling and access to the stairwell, or to the equivalent space, when there is no well defined, not exceed 10 m; otherwise, the building must be served by more than one staircase.”

Decreto-Lei nº 64/90 de 21-02-1990 de Fevereiro
[Fire Safety Regulations in Housing]

6 Storeys
Kenya permits a single exit for any building up to 6 storeys in building height or where the floor level of the uppermost storey is not more than 17m above grade.

Any Basement or Above Ground Storey

3.4.6.12
A building with a storey above or below the ground level shall be served by not less than two separate stairways; and the entrance to the emergency stairway shall not be less than 5.0 meters from the entrance to any other stairway.

3 Storeys
South Africa permits a single exit for buildings up to 3 storeys in building height.

21.5m
Turkey permits a single exit for buildings with a height of not more than 21.50m.

15m
The UAE permits a single exit for buildings up to 15m in building height where an automatic sprinkler system is provided, with a maximum floor area per storey of 500m² and where there are not more than 4 dwelling units per storey.

29m
The Israeli code permits a single exit for buildings not more than 29m in building height. Buildings up to 13m in height can have a single unprotected stair. The Israeli 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.

30m / 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.

According to a local architect, 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 dwelling units per floor.

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.”

15m
India permits a single exit for multi-unit residential buildings up to 15m in building height with a maximum floor area of 500m² per storey.

Unconfirmed
Bangladesh does not specify a maximum building height for single exit residential buildings, but provides a maximum occupant load of 50, corresponding to a maximum floor area of 900m2.

Article 3.14.2 specifies that a minimum of 2 exits is required where the occupant load exceed 50 in a space. For residential uses (Classification A), occupancy load is calculated as 1 occupant per 18m2 in gross floor area (Table 4.3.1.).

Article 3.14.3 also specifies that a high-rise building with a floor area larger than 500m² on each floor for educational, institutional, assembly, storage or a mixed occupancy shall have a minimum of two staircases. A high-rise building “is defined as any building which is more than 10-storey or 33 m high from reference datum.”

18 Storeys
China permits a single exit for multi-unit residential buildings up to 18 storeys in building height with a maximum floor area of 650m² per storey. A maximum travel distance of 15m from the dwelling unit door to the exit applies for buildings less than 10 storeys in height, which is shortened to a maximum travel distance of 10m for buildings between 10 and 18 storeys in height.

No Maximum Height Limit
South Korea does not set a maximum building height for multi-unit residential buildings with a single exit stair. The code limits single exit stair conditions only based on horizontal limits, including a maximum inhabited floor area of 300m² per storey and no more than 3 dwelling units per storey and travel distance limits. Article 35 requires the single exit stair to be a ‘firefighting’ stair (safe evacuation stair) for apartment buildings of 16 or more storeys.

5 Storeys (No Limit)
Japan’s building code includes several trigger levels to define permitted conditions for single staircase buildings in both residential or office buildings:

• For buildings of up to two storeys in height, a single open staircase (without corridor separation) is permitted to serve a maximum floor area per storey of 200m² for combustible construction and 400m² for non-combustible construction. A fire sprinkler system is not required.
• For buildings of three to five storeys in height, a single ‘fire-compartmented’ staircase (i.e. corridor separation) is permitted to serve a maximum floor area per storey of 100m² for combustible construction and 200m² for non-combustible construction. A fire sprinkler system is not required.
• For buildings of six to fourteen storeys, a single exterior staircase is permitted and for buildings of fifteen or more storeys and a single ‘fire-compartmented’ staircase with a vestibule is permitted to serve a maximum floor area per storey of 100m² for combustible construction and 200m² for non-combustible construction. A fire sprinkler system is required for buildings of 11 or more storeys in height. An evacuation balcony and hatch is also required for buildings of six or more storeys in height served by a single staircase.

Singapore

60m
Singapore permits a single exit in apartment buildings up to 24m so long as the one-way travel distance is complied with, and exceeding 24m in height under the following conditions:

(a) The building’s habitable height does not exceed 60m, unless otherwise permitted by the SCDF.

(b) The single exit staircase shall serve not more than four apartments or maisonettes at each storey.

(c) Provision of exits for each residential apartment or maisonette shall comply with the requirements under Cl.9.2.1a.(5).

(d) Travel distance from the most remote exit door to the exit staircase from each apartment or maisonette shall not exceed 15m.

(e) The approach to the exit staircase shall be through cross-ventilated corridor/lobby in accordance with Cl.1.4.28, except that the ventilation openings shall have a minimum width of 2m and a minimum height of 1.2m, as well as the following requirements:

(i) the openings shall be unobstructed from the parapet wall or balustrade level upwards and be positioned on opposite sides of the corridor/lobby such that they provide cross ventilation throughout the entire space of the corridor/lobby; and

(ii) the entire cross-ventilated corridor/lobby shall be unobstructed and maintained at minimum 2m width throughout.

(f) Where multiple ventilation openings are provided on opposite sides of the corridor/lobby, the minimum width and height of each opening shall not be less than 1m and 1.2m respectively, provided the aggregate width of the openings at each opposite side is not less than 2m. (See Diagram 9.2.1a.(4)(f))

6 storeys or 17m (uppermost finish floor height)

(1)    Every building shall be provided with such means of escape in case of emergency as may be required by the intended use of the building.

(2)    Without prejudice to paragraph (1), every building which exceeds 6 storeys in height or in which the level of the floor of the uppermost storey is more than 17 m 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. (L.N. 294 of 1976)

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