Evacuation alert systems (BS 8629): who needs one and what is involved

Most blocks of flats are designed for a “stay put” strategy: a fire is contained within the flat where it starts, and other residents are safer staying in their own flats unless they are directly affected. An Evacuation Alert System (EAS) exists for the occasions when that strategy has to change. It gives firefighters a way to tell residents on particular floors to leave, without sending someone to knock on every door.

What it is, and what it is not

An evacuation alert system is a facility for the fire and rescue service. It consists of:

• a control panel, the Evacuation Alert Control and Indicating Equipment (EACIE), in a locked cabinet near the entrance firefighters normally use;
• an alert device, normally a sounder, in the hallway of every flat, with visual devices where residents need them;
• power supplies, standby batteries and fire-resisting cables connecting them.

It is deliberately not a fire alarm. It has no smoke or heat detectors and no manual call points, nothing in it operates automatically, and BS 8629 recommends keeping it separate from any fire detection and fire alarm system in the building. Residents cannot set it off. Only firefighters operate it, floor by floor, once they have decided evacuation is needed.

It is also not a voice alarm. It sounds a tone, not a spoken message. Voice alarm systems are covered by BS 5839-8; see which emergency sound standard applies.

Which buildings are expected to have one

BS 8629 does not decide whether a building needs an evacuation alert system; it sets out how to provide one where it is needed (BS 8629, Clause 4.1). The decision comes from building regulations guidance and the building’s fire strategy:

• England. The December 2022 amendment to Approved Document B introduced a recommendation for an evacuation alert system, to BS 8629, in new blocks of flats with a top storey more than 18 m above ground level (Approved Document B Volume 1, paragraph 15.17). Whether a particular building is caught depends on when its building work was approved and started, so check the building control approval rather than assuming.
• Scotland. The Domestic Technical Handbook has recommended evacuation alert systems in new blocks of flats with any storey more than 18 m above ground since 2019.
• Existing buildings. There is no general requirement to retrofit, but a fire strategy review, a fire risk assessment or a fire and rescue service may recommend one. BS 8629 recommends consulting the local fire and rescue service before design starts.

How it works in a fire

Firefighters open the cabinet with a key they carry. Inside, there is one on/off switch and one red indicator for each evacuation alert zone, normally one zone per storey, laid out in a vertical column that mirrors the floors of the building. To evacuate the fire floor and the floors next to it, the incident commander turns on those floors’ switches, and the sounders in those flats operate within seconds (BS 8629, Clause 13.2.2).

Two design choices follow from this:

• There is no “evacuate all” button. BS 8629 recommends against a single control that alerts the whole building at once (Clause 13.2.2 n)). Evacuation is meant to be controlled floor by floor so that stairs do not fill with people from floors that are not at risk while firefighters are using them.
• Each zone works independently. A fault in one flat or one floor should not stop the system working elsewhere, and the system should keep operating on the most floors possible even with two faults at once (Clause 8.2.2).

Key recommendations

Topic	BS 8629 recommends	Clause
Sound level at bedroom doors	At least 85 dB(A) at the doorway of each bedroom, with the door open	10.2 c)
Sound level in living rooms	At least 60 dB(A) in the principal habitable room	10.2 d)
Tone	A frequency between 500 Hz and 1 000 Hz, the same signal throughout the building	10.2 a)
Zoning	No zone larger than one storey; normally one zone per storey	9.2 c)
Control panel cabinet	Secure, lockable with the fire service key, near the fire service entry point	13.2.1
Standby battery	72 hours of normal running, then 30 minutes with every zone sounding; 24 hours plus 30 minutes only where an automatically started generator also serves the system and common-area lighting, and staff are present at all times	14.4 e)
Cables	Enhanced (120-minute) fire-resisting cable on the paths from the panel to the devices	15.2

The 72-hour standby figure is three times the 24 hours usual for a voice alarm. A residential block has no staff to notice a mains failure, so the system has to keep going for a long weekend on batteries.

Certificates at handover

BS 8629 recommends separate certificates for design, installation and commissioning, even when one company does all three, plus an acceptance certificate signed by the building owner or their representative (Clause 20.3). Commissioning should confirm the sound levels in every flat and that each switch sounds its own floor and only that floor (Clause 20.1.2 c)). The owner should also receive as-fitted drawings showing actual cable routes, an operating and maintenance manual and a logbook (Clause 20.2.2).

Maintenance

Because residents must never learn to ignore the sound, BS 8629 deliberately keeps testing infrequent and in the hands of a competent person:

• At least monthly: a named member of premises management checks that the control panel is in good order, shows no faults and has not been tampered with (Clause 22.1.2 a)).
• Every six months: a competent person inspects, tests and services the system, including proving the power supply on load and operating each floor’s switch in turn, then issues a servicing certificate. If the six-monthly service is missed, the system no longer conforms to the standard (Clause 21.1.2).
• Over each 12 months: every alert device is tested briefly, usually by listening at the flat door (Clause 21.1.2 c)).
• On a fault: the maintainer attends, normally within 8 hours (Clause 21.2.2 a)).

Fire and rescue service familiarisation visits are encouraged, but should not sound the alert signal, for the same reason.

Residents need to know what it means

An evacuation alert system only works if residents leave when their sounder operates. BS 8629 recommends that premises management tell residents to evacuate without delay if their device sounds, and to report fault warnings, and that premises management work with residents so that changes to a flat’s layout do not stop the device being heard (Clause 22.1.2). Fire action notices in the building should say the same.

Edition note

The current edition is BS 8629:2019+A1:2023. The 2023 amendment expanded the recommendations on fault monitoring, audibility, arrangements for disabled residents, networked systems and maintenance, and uses “premises management” where the 2019 text said “user”. If you are working from a 2019 copy, check those areas against the amended text.