New Swedish building regulations and a framework for fire safety engineering

Caroline Cronsioe, The National board of building, housing and planning

Michael Strömgren, SP Fire technology David Tonegran, Tyréns Henrik Bjelland, University of Stavanger

Content

The Swedish concept for performance-based design

New buildings vs. Alteration Analytical design procedures

European possibilities

Swedish regulatory hierarcy

General recommendations for analytical design

Example, hierarcy

Buildings shall be designed with adequate protection against fire spread between buildings.

Adequate protection is achieved if buildings are constructed at a distance of more than 8 m. /…/

Limiting the risk of fire spread between buildings can be achieved, for example, by: - buildings being erected at a suitable distance from each other, - restricting the size of unprotected building components, - restricting the fire susceptibility of exposed surfaces, or - restricting the extent of the fire with fire safety installations such as an automatic fire suppression system. For analysis of fire spread between buildings, the maximum radiation levels on the exposed building should not exceed acceptable levels for all relevant scenarios.

Protection against the spread of fire between buildings Mandatory provisions (Operative requirements)

General recommendation (Analytical design)

General recommendation (Prescriptive design or acceptable solution)

General recommendations for analytical design

Foto: Otto Ryding

1. Buildings shall comply with the fire protection

regulations for new buildings

2. The mandatory provisions may be

satisfied in a other way if the corresponding safety

level is still achieved

3. Deviations from the safety level may be made if there are exceptional

circumstances

Main rule Not always possible to fulfill

Every building has its unique problems and solutions All buildings, built yesterday or those built in the 15th century

Analytical design is possible to use

When building a new building you always need to fulfill the mandatory provisions When altering a building is not always possible to fulfill the mandatory provisions For a few buildings this 2nd step is still not enough

If deviations from the mandatory provisions are made (step 2 and 3), the design shall be verified with analytical design

Fire regulations Alterations of buildings

Analytical design procedures

Required for certain buildings and when deviating from prescriptive regulations

Possible for both new and altered buildings

General process Identifying deviations from

prescriptive code Verifying the tradeoffs Review & documentation

Verification procedures

Verifying operational requirements Comparative analysis (prescriptive solutions) Design criteria for certain scenarios

Verification methods Qualitative assessment (limited use) Scenario based analysis Quantitative risk analysis

Robustness assessment, sensitivity and uncertainty analysis may be required

Example: Verifying means of escape by scenario analysis Three design scenarios with various design

fires (for RSET) Recommended minimum values: 5 and

10 MW Robustness: 2 MW Effect of sprinklers

Design conditions for ASET Pre-movement time Travel time

Design criteria For example, 80C Temperature, 5 m

visibility etc.

Status of FSE in Europe

Most countries use prescriptive regulations as a base for FSE

Competence levels among practitions vary

Regulatory support and methods for FSE is lacking

However, complex buildings deviating from prescriptive regulations are built any way

Challenges for Europe

Need for FSE tools and harmonisation

Account must be taken for differences in Legal and regulatory structures Review & control processes Competence levels among practitioners

Work is going on in European

standardization and in SFPE Europe

Conclusions

Balance between flexibility and societal risk control

Need for risk calibration and risk criteria – these should be set nationally…

… and the risk level of prescriptive regulations is a good start

European countries should adopt a common method and approach to FSE