BS 9999¶
British Standards Institution (BSI) (2017) BS 9999:2015 Fire safety in the design, management and use of buildings – Code of practice.
BS 9999 provides guidance on fire safety in the design, management and use of buildings.
This module provides calculations for fire safety in buildings as specified in BS 9999, the UK code of practice for fire safety design, management and use of buildings.
BS 9999 provides methodologies for fire safety engineering calculations including egress calculations, fire safety systems design, and building fire safety management.
- Available modules:
chapter_15: Chapter 15 - Means of escape calculations
Example
>>> import ofire
>>> ofire.bs9999.chapter_15
Chapter 15¶
This module provides calculations for means of escape from buildings as specified in BS 9999 Chapter 15, including exit width calculations for different stair configurations.
Example
>>> import ofire
>>> ofire.bs9999.chapter_15.figure_6a.calculate_exit_width(1000.0, 2.0, 5, 0.5, 40.0)
Figure 6a - Exit Width for Stairs Serving Upper Floors Only¶
Calculations for required exit width of stairs that only serve floors above the ground level, based on BS 9999 fire safety requirements.
- ofire.bs9999.chapter_15.figure_6a.calculate_exit_width(s_up, w_se, n, d, x)¶
Calculate exit width for stairs serving upper floors only.
This function calculates the required exit width for stairs that only serve floors above the ground level, based on BS9999 fire safety calculations.
\[\begin{split}W_{fe} = \begin{cases} S_{up} + W_{se} & \text{if } n > 60 \text{ and } d < 2.0 \\ n \cdot x + 0.75 \cdot S_{up} & \text{otherwise} \end{cases}\end{split}\]where:
\(W_{fe}\) is the required exit width (m)
\(S_{up}\) is the total floor area served by the stair on upper floors (m²)
\(W_{se}\) is the width of exit at discharge level (m)
\(n\) is the number of floors served by the stair above discharge level (floors)
\(d\) is the design occupant density (persons/m²)
\(x\) is the stair flow capacity (persons/m/min)
- Parameters:
s_up (float) – Total floor area served by the stair on upper floors (m²)
w_se (float) – Width of exit at discharge level (m)
n (float) – Number of floors served by the stair above discharge level (floors)
d (float) – Design occupant density (persons/m²)
x (float) – Stair flow capacity (persons/m/min)
- Returns:
Required exit width (m)
- Return type:
- Assumptions:
To be completed
- Limitations:
To be completed
Example
>>> import ofire >>> width = ofire.bs9999.chapter_15.figure_6a.calculate_exit_width(1000.0, 2.0, 5, 0.5, 40.0) >>> print(f"Exit width: {width} m")
Figure 6b - Exit Width for Stairs Serving Upper and Lower Floors¶
Calculations for required exit width of stairs that serve both floors above and below the ground level, based on BS 9999 fire safety requirements.
- ofire.bs9999.chapter_15.figure_6b.calculate_exit_width(b, d, s_up, s_dn, x)¶
Calculate exit width for stairs serving upper and lower floors.
This function calculates the required exit width for stairs that serve both floors above and below the ground level, based on BS9999 fire safety calculations.
\[\begin{split}W_{fe} = \begin{cases} S_{up} + S_{dn} & \text{if } b > 60 \text{ and } d < 2.0 \\ b \cdot x + 0.75 \cdot S_{up} & \text{otherwise} \end{cases}\end{split}\]where:
\(W_{fe}\) is the required exit width (m)
\(S_{up}\) is the total floor area served by the stair on upper floors (m²)
\(S_{dn}\) is the total floor area served by the stair on basement floors (m²)
\(b\) is the number of basement floors served by the stair (floors)
\(d\) is the design occupant density (persons/m²)
\(x\) is the stair flow capacity (persons/m/min)
- Parameters:
b (float) – Number of basement floors served by the stair (floors)
d (float) – Design occupant density (persons/m²)
s_up (float) – Total floor area served by the stair on upper floors (m²)
s_dn (float) – Total floor area served by the stair on basement floors (m²)
x (float) – Stair flow capacity (persons/m/min)
- Returns:
Required exit width (m)
- Return type:
- Assumptions:
To be completed
- Limitations:
To be completed
Example
>>> import ofire >>> width = ofire.bs9999.chapter_15.figure_6b.calculate_exit_width(2.0, 0.5, 1000.0, 500.0, 40.0) >>> print(f"Exit width: {width} m")
Figure 6c - Exit Width for Complex Stair Configurations¶
Calculations for required exit width of stairs with complex configurations serving multiple floors above and below ground level.
- ofire.bs9999.chapter_15.figure_6c.calculate_exit_width(b, n, d, s_up, s_dn, w_se, x)¶
Calculate exit width for complex stair configurations.
This function calculates the required exit width for stairs with complex configurations serving multiple floors above and below ground level, including considerations for exit width at discharge level, based on BS9999 fire safety calculations.
\[\begin{split}W_{fe} = \begin{cases} S_{up} + S_{dn} + W_{se} & \text{if } (b + n) > 60 \text{ and } d < 2.0 \\ b \cdot x + n \cdot x + 0.75 \cdot S_{up} & \text{otherwise} \end{cases}\end{split}\]where:
\(W_{fe}\) is the required exit width (m)
\(S_{up}\) is the total floor area served by the stair on upper floors (m²)
\(S_{dn}\) is the total floor area served by the stair on basement floors (m²)
\(W_{se}\) is the width of exit at discharge level (m)
\(b\) is the number of basement floors served by the stair (floors)
\(n\) is the number of floors served by the stair above discharge level (floors)
\(d\) is the design occupant density (persons/m²)
\(x\) is the stair flow capacity (persons/m/min)
- Parameters:
b (float) – Number of basement floors served by the stair (floors)
n (float) – Number of floors served by the stair above discharge level (floors)
d (float) – Design occupant density (persons/m²)
s_up (float) – Total floor area served by the stair on upper floors (m²)
s_dn (float) – Total floor area served by the stair on basement floors (m²)
w_se (float) – Width of exit at discharge level (m)
x (float) – Stair flow capacity (persons/m/min)
- Returns:
Required exit width (m)
- Return type:
- Assumptions:
To be completed
- Limitations:
To be completed
Example
>>> import ofire >>> width = ofire.bs9999.chapter_15.figure_6c.calculate_exit_width(2.0, 5.0, 0.5, 1000.0, 500.0, 2.0, 40.0) >>> print(f"Exit width: {width} m")