Under Article 32(6) of the Turkish Regulation on Fire Protection of Buildings (BYKHY), the furthest point from which travel distance is measured is taken 40 cm in front of the walls enclosing the space. The maximum travel distances are given in Annex 5/B according to the use class and whether there is a sprinkler system: for example, in an office building one-way travel is 15 m (no sprinklers) or 30 m (sprinklers), and two-way travel is 45 m or 75 m.
Measurement rules of Article 32
- Article 32(3): the travel distance may not be greater than the values given in Annex 5/B for the use class.
- Article 32(4): the distance from the furthest point in a space to the nearest exit may not exceed the Annex 5/B limits.
- Article 32(5): on a large floor divided into rooms and corridors, the direct (as the crow flies) travel distance is accepted if it does not exceed 2/3 of the maximum distance in Annex 5/B.
- Article 32(6): for the measurement, the furthest point is taken 40 cm in front of the walls enclosing the space.
- Article 32(7): in places such as hospitals where a horizontal evacuation area with at least 60 minutes fire resistance and protection against smoke passage is provided, the travel distance is measured to the exit door of the corridor leading to the horizontal evacuation area; at least one protected escape route is reached from each horizontal evacuation area.
- Article 32(8): in shops and similar places on the ground floor, a single exit to the outside is sufficient if there are fewer than 50 people and the distance from the furthest point to the door opening to the outside is less than 25 m.
Annex 5/B: maximum travel distances to exits
| Use class | One way, no sprinklers (m) | One way, sprinklers (m) | Two way, no sprinklers (m) | Two way, sprinklers (m) | Dead-end corridor, without / with (m) |
|---|---|---|---|---|---|
| High hazard places | 10 | 20 | 20 | 35 | 10 / 20 |
| Industrial buildings (1) | 15 | 25 | 30 | 60 | 15 / 20 |
| Dormitories, sleeping quarters | 15 | 30 | 45 | 75 | 15 / 20 |
| Stores, shops, supermarkets | 15 | 25 | 45 | 60 | 15 / 20 |
| Office buildings | 15 | 30 | 45 | 75 | 15 / 20 |
| Car parks and warehouses | 15 | 25 | 45 | 60 | 15 / 20 |
| School and educational buildings | 15 | 30 | 45 | 75 | 15 / 20 |
| Assembly buildings | 15 | 25 | 45 | 60 | 15 / 20 |
| Hospitals, care homes | 15 | 25 | 30 | 45 | 15 / 20 |
| Hotels, guesthouses | 15 | 20 | 30 | 45 | 15 / 20 |
| Apartment buildings | 15 | 30 | 30 | 75 | 15 / 20 |
(1) In industrial buildings that do not produce easily ignitable materials, the one-way and two-way distances may be increased by 1/2. According to the table note, for external escape passages the distances for sprinklered buildings apply, and for open car parks the distances for sprinklered car parks apply. Annex 5/B also gives the number of persons per unit width; for those columns see the table in the regulation.
Field note
Measuring from the furniture layout plan is a common mistake. Article 32(6) fixes the measuring point 40 cm inside the wall regardless of furniture, so the travel distance does not change even if the layout changes. The second mistake is using the sprinklered column and then removing the system from the design: the choice of column must be consistent with the actual sprinkler coverage in the design.
Checklist
- Has the use class been matched to an Annex 5/B row?
- Is the sprinklers yes/no column consistent with the design?
- Has the furthest point been taken 40 cm inside the wall (Article 32(6))?
- If a direct (as the crow flies) measurement was used, is the 2/3 rule met (Article 32(5))?
- Is the dead-end corridor length within the Annex 5/B limit?
FAQ
What is the 40 cm rule in travel distance measurement?
Under BYKHY Article 32(6), the furthest point from which travel distance is measured is taken 40 cm in front of the walls enclosing the space, inside the space. The measurement starts not from the wall surface but from the point 40 cm inside the wall.
What is the maximum travel distance in an office building?
Under Annex 5/B, in office buildings the one-way travel distance is 15 m without a sprinkler system and 30 m with one; the two-way travel distance is 45 m without a sprinkler system and 75 m with one.
When is a direct (as the crow flies) measurement accepted?
Under Article 32(5), on a large floor divided into rooms and corridors, the direct (as the crow flies) travel distance is accepted if it does not exceed 2/3 of the maximum distance permitted in Annex 5/B.
References
- Turkish Regulation on Fire Protection of Buildings (BYKHY), Official Gazette 19.12.2007/26735 and amendments; Article 32, Annex 5/A, Annex 5/B. mevzuat.gov.tr
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Download MEP Calc on the App StoreSources are listed in the References section at the end of the article. Quotations from the regulation are unofficial English translations of the Turkish text. This article is for general information; for article numbers, thresholds and exemptions, the current regulation and standard texts published in the Official Gazette govern, and design must be carried out by an authorised engineer.