Fire safety systems and smoke control: the basics

On site, fire safety isn't a trade like any other: it crosses HVAC, electrical and architecture, and it's heavily regulated. Here are the basics to find your way, especially around fire safety systems and smoke control. French terms are common in this field, with equivalents.

What is a fire safety system (SSI)?

The fire safety system (SSI) brings together all the equipment that detects a fire and puts the building into safety. It is mainly made of the detection system (SDI) and the safety actuation system (SMSI), which drives the safety functions.

SSI categories

There are five categories, from A (the most complete, generalised automatic detection) to E (the simplest). The choice depends on the building type (public-access buildings, high-rises…) and the risk level. The higher the category, the more demanding the system.

Smoke control

Smoke control extracts smoke from a fire to protect escape routes and help the emergency services. It can be natural (openings, roof vents) or mechanical (fans, dedicated ductwork). For HVAC, it's a major coordination point: ducts, dampers, smoke-extraction fans.

Compartmentation and evacuation

Two other key functions: compartmentation (fire doors, dampers) which limits spread, and evacuation (alarm, corridor smoke control, safety lighting). The SMSI orchestrates all of this.

What it means for planning

Fire safety requires tests, acceptance by the safety commission and tight coordination between trades. Anticipating it in the schedule avoids nasty surprises at the end of the project — especially in public-access and high-rise buildings, where requirements are strict.