An access control system decides who opens which door, and when. The lock is the easy part. The hard part — and the part that gets designs rejected — is guaranteeing that everyone can still get out when the fire alarm sounds.
Get the egress side wrong and you haven't built a security system. You've built a trap with a card reader on it.
We've been supplying this kit from Villa Road in Birmingham since 1975. Here's the order we'd think it through in.
1. Fail-safe or fail-secure — decide this first
Two words, opposite behaviours, and people mix them up constantly.
- Fail-safe (power-to-lock): the lock needs power to stay locked. Cut the power and the door opens. Magnetic locks are inherently fail-safe.
- Fail-secure (power-to-open): the lock needs power to release. Cut the power and the door stays locked.
On an escape route, fail-safe is almost always the answer, because a power failure must not leave people shut in. On a store room holding stock you'd rather not lose in a blackout, fail-secure makes sense.
Our position: work out the escape route first, then pick the lock. Not the other way round.
2. The egress requirement, stated plainly
A door on a means of escape has to release. That normally means three independent things:
- An interface to the fire alarm so the lock drops when the alarm activates. In the UK the actuation of release mechanisms on escape-route doors is covered by BS 7273-4, and how it's applied depends on the building.
- A manual emergency door release at the door, reachable without a key, card or code.
- A safe failure mode — the fail-safe behaviour above.
The EDR-1N is the one we sell most of — an illuminated, resettable emergency door release running 12/24 V, IP24 rated for internal use. Resettable matters: a break-glass unit is a consumable and someone has to carry spare elements, whereas a resettable unit is tested and put back.
Trade Tip: Specify the release at the same moment you specify the lock, on the same line of the quote. The commonest failure we see isn't a bad lock — it's a beautifully installed maglock with no emergency release on the escape side, discovered by whoever signs off the building. Retrofitting one means chasing a wall that's already been decorated.
3. Choosing holding force
Magnetic locks are rated by holding force. More is not automatically better — a hollow internal door frame will deform long before a 500 kg lock lets go, and you've paid for force the door cannot use.
Match the lock to the leaf and the frame:
- Internal timber and glazed office doors: a slimline unit is usually right.
- External or high-traffic doors: step up, and check the frame can carry it.
See our full guide to magnetic door locks for how holding force, monitoring and brackets interact.
4. Monitored locks, and why they earn their money
A monitored lock reports its own state back to the system — bonded or not bonded. Unmonitored locks do not.
The value shows up in ordinary use: a door held open on a mat, a leaf that's dropped on its hinges and no longer makes contact, a lock that thinks it's locked and isn't. Without monitoring, nobody knows until something goes missing.
The RGL ML600-D-M is a double monitored slimline maglock rated 2 × 600 lb — the double version for pairs of doors. The single equivalent, the ML600-M, is a monitored 600 lb (280 kg) unit running 12/24 V.
Trade Tip: Buy monitored even where the specification doesn't demand it. The extra cost is small, and the first time a door quietly stops locking overnight you'll have a log entry instead of an insurance conversation.
5. Brackets are not an afterthought
A maglock only works if the armature meets the lock face square, with a small consistent air gap. Inward-opening doors, glass doors and frameless leaves all need the right bracket to achieve that.
We stock Z and L brackets for inward-opening doors and surface armature housings where the armature cannot be recessed. If the armature sits at an angle or the gap varies across the face, holding force drops away and the door starts to rattle open.
6. Readers, and keeping it simple
Card, fob, keypad, biometric or intercom — the reader is the bit users see and the bit that generates support calls. Two honest observations from the counter:
- Codes get shared. If access needs to be revocable per person, a code on a keypad is not it.
- Every credential type needs an administrative process behind it. A system nobody updates when staff leave is a list of former employees who can still get in.
Where the door is also an entrance visitors use, a video door station often does more work than a reader — see our guide to video intercoms.
Summary: specifying access control
| Stage | Decision |
|---|---|
| 1. Escape route | Identify it before choosing any lock |
| 2. Failure mode | Fail-safe on escape routes; fail-secure only where egress is unaffected |
| 3. Fire interface | Release on alarm activation, per BS 7273-4 as applied to the building |
| 4. Manual release | Emergency door release at the door — resettable, illuminated |
| 5. Holding force | Matched to leaf and frame, not maximised |
| 6. Monitoring | Monitored, even when not specified |
| 7. Brackets | Z/L or surface armature to suit the door swing |
| 8. Sign-off | Competent person. Escape-route work is not a DIY exercise |
Expert Help in the West Midlands
Villa Road, Birmingham, since 1975. Bring the door — or photographs of the leaf, the frame and the swing direction — and we'll work out the lock, the bracket and the release together, in one go, rather than you discovering the bracket problem on site.
Where a door sits on an escape route, get the fire-alarm interface designed by a competent person. We'll supply the parts and tell you honestly where the line is.
Frequently asked questions
What is the difference between fail-safe and fail-secure?
Fail-safe locks need power to stay locked, so they release when power is lost — the normal choice on escape routes. Fail-secure locks need power to release, so they stay locked in a power cut.
Do I need an emergency door release with a magnetic lock?
On a door forming part of a means of escape, yes — a manual release reachable without a card, code or key, alongside an interface that drops the lock when the fire alarm activates.
Does a bigger magnetic lock mean a more secure door?
Only up to the point the door and frame can carry. Beyond that the frame gives way first, so extra holding force buys nothing. Match the lock to the leaf.