Buildings usually decide they need access control on an ordinary morning: a master key goes missing, a staff member leaves badly, or somebody asks who was in the building on the weekend, and there is no answer. Keys do not keep records and they cannot be taken back without changing cylinders.
An access control system replaces the key with a credential the building can issue, restrict and revoke, and it writes down every use.
How a controlled door actually works
Five parts, working as one sequence.
The credential is what the person carries: a fob, a card, a phone or a fingerprint. The reader at the door sees the credential and passes it to a controller, a small panel usually mounted in a comms room. The controller decides in a fraction of a second whether this person may open this door at this time, and if the answer is yes it releases the electrified lock.
Two more parts get forgotten in cheap installs, and they are the ones that make the system honest. A door position switch tells the controller whether the door is actually closed, so it can tell the difference between a normal entry and a door held open. A request to exit device lets people leave freely while still recording that the door opened.
Without those two, the system knows who unlocked the door but not what the door did next, and the log becomes a story with pages missing.
Credentials, honestly compared
- Cards and fobs are cheap and universal, and modern encrypted formats resist the copying kiosks that defeated the old ones
- Mobile credentials live on a phone, which people guard far better than a fob, and they can be issued and revoked remotely
- PIN codes cost nothing but get shared, so they belong on low risk doors or as a second factor rather than a primary
- Biometrics tie access to a person rather than an object, at a higher price and with privacy obligations to take seriously
Most buildings run a mix, and the right question is per door, not per building.
The locking hardware decision
Electric strikes and magnetic locks both hold doors, and the difference matters at the worst possible moment. Fail safe hardware releases when power is lost, fail secure stays locked. Egress paths and fire code decide which is legal on which door, which is why this choice belongs to the design stage and not to whatever was on the truck.
Every door with a maglock also needs a compliant way out with no credential at all, because people must always be able to leave.
The software is the product
Hardware opens doors. The software is where the value lives: who has access to what, on which schedule, with an audit trail you can actually search. Cleaners get weekday evenings, contractors get two weeks that expire on their own, a departed employee is removed in one action across every door, and the Monday question of who entered on Saturday has a printable answer.
What separates a good install
- Fail safe or fail secure decided door by door, against code
- Fire alarm tie in tested, not assumed
- Door position and request to exit on every controlled door
- Controller capacity and cabling with room for the doors you will add later
- An administrator on your staff trained to run it, so routine changes do not need a service call
Access control is one of the few systems that pays back in both directions: fewer locksmith visits and rekeys, and a record that ends arguments about what happened. The buildings that get the most from it are the ones that treated the first install as infrastructure rather than as a gadget on one door.
Treating it as infrastructure is how we approach every access control system we install: each door is designed on its own, with the lock type decided against code, door position and request to exit fitted as standard, and the fire alarm release wired and tested rather than assumed. The front entrance almost always needs one more piece, because visitors and couriers without a credential still have to get in. A video intercom at that door lets reception see and speak to whoever is there and release the lock from a desk or a phone, using the same controller and audit trail as every other door in the building.
Common questions
Can an access control system work with a video intercom?
Yes, and at a main entrance the two belong together. The intercom handles people who have no credential: a visitor presses the button, staff see and speak to them on a desk console or a phone, and a release command opens the same electrified lock that badges normally control. Because the release passes through the access controller, the event is logged like any other entry, so the building still knows who opened that door and when.
What happens to the doors if the access control system loses power or the network fails?
A properly designed system keeps working. Controllers hold their own copy of the credentials and schedules, so they keep deciding who may enter even when the server or the network is unreachable, and they store the events to upload later. Power supplies for locks and controllers carry battery backup for outages. If power is lost completely, each door behaves as its lock type dictates: fail safe hardware releases and fail secure hardware stays locked, while egress always remains free.
Can access control be added to an existing door?
Almost always. A standard hinged wood or metal door takes an electric strike or a maglock along with a reader and door position switch. Aluminum storefront and glass doors have their own hardware options and need a closer look at the frame. Fire rated doors must keep their rating, so only listed hardware installed the right way is acceptable on them. The main constraint is usually getting cable to the door frame cleanly, which is a planning question rather than a barrier.
Should I choose cloud based or on premises access control?
Cloud based systems host the software for you, so you manage every site from a browser, receive updates automatically and have no server to maintain, in exchange for a subscription. On premises systems keep the software on your own server, which some organisations prefer for control or policy reasons. In both cases the controllers at the doors keep working if the connection drops, so the decision is about how you want to administer the system, not about whether the doors will open.
If your building is still handing out keys it cannot get back, our access control team can design the system door by door and train your staff to run it. Contact us to arrange a walk-through.
