Door entry systems explained: types and how to choose

Every controlled door is really answering one question, over and over: should this person be allowed in? A door entry system answers it for you - letting the right people through and keeping everyone else out - without someone having to get up and check each time the buzzer goes. From a single office door to a school's front entrance or a block of flats, the job is the same; it's the scale and the features that change.

The choices come down to whether you just need to talk to callers, see them as well, or control access with codes and fobs - then sizing the system to your building and making sure that however the door locks, people can always get out safely. Here's how it fits together.

What a door entry system is made of

Whatever the type, most systems share the same handful of parts. There's an entrance panel on the outside - the bit with the call button, and often a camera, keypad or card reader. Inside there's a handset or monitor to answer the call and release the door. Between them sits the door release itself - an electric lock that unlocks on command - plus a power supply to run it all, and usually an exit button or sensor to let people out from inside. Understand those pieces and every system, however grand, is just a variation on the same theme.

The main types

Plenty of real installations mix these - a video panel at the main entrance, keypads or fobs on internal doors, all tied together. The types aren't rivals so much as building blocks.

Codes, fobs or an app?

Where a system controls access rather than just answering the door, the credential matters. A keypad needs no hardware in anyone's pocket, but a shared code is only as secure as the people who know it, and it needs changing now and then. Proximity fobs and cards are quick to use and, crucially, can be issued and revoked per person - lose a fob and you cancel that one rather than re-keying the building, which is why they suit workplaces with staff coming and going. Networked and app-based systems go further, letting you manage who has access to which door from a screen and see a log of who went where. The more people and doors you're dealing with, the more that central control earns its place.

How the door releases - and the safety bit

Two common releases do the actual unlocking. An electric strike replaces the standard keep so the door can be buzzed open, while a magnetic lock (maglock) holds the door shut with an electromagnet that releases when power is cut. That difference matters for safety: on escape routes you'll generally want a fail-safe arrangement that releases and lets people out if the power fails or the fire alarm sounds. Free, safe exit always comes first - a door entry system controls who gets in, but it must never stop anyone getting out, and any install needs to respect the building's fire regulations. It's the one part of the decision worth taking slowly and, for anything beyond a simple door, checking with whoever signs off your fire safety.

Choosing for your building

Start from the building and the people. A single office or entrance is well served by a straightforward audio or video door entry panel. A school leans toward video, so staff can see and verify a caller before releasing a controlled single point of entry - a genuine safeguarding win. Multi-occupancy residential needs a panel that can call many flats; a commercial site with lots of staff wants fobs or cards and, before long, networked control. Check whether the outside panel needs to be weatherproof, think about how far it might grow, and consider tying it in with your wider security - CCTV and alarms - so it's one joined-up picture rather than three separate ones.

The short version

Decide whether you need audio, video or full access control, size it to your doors and users, choose a release that always allows safe exit, and think about growth and integration before you buy. Get that right and the system quietly does its job: the right people in, everyone else out, and no one held up at the door.

Browse our range of door entry systems and the wider security and ironmongery range, or request a quote if you're specifying for a site or a school.

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Frequently asked questions

What's the difference between audio and video door entry?

An audio intercom lets you speak to a caller and release the door, but you can't see them. A video door entry system adds a camera in the entrance panel so you can see who's there before you let them in - useful for reception areas, schools and anywhere verifying the caller matters.

What is access control?

Access control is any system that decides who can open a door, usually by PIN code, a proximity fob or card, or an app - rather than by answering an intercom. It lets you give and remove access per person and, on networked systems, see a log of who entered which door and when.

Are keypads or fobs better for door access?

Keypads need no hardware to carry, but a shared code has to be trusted to everyone who knows it and changed periodically. Fobs and cards are issued per person and can be cancelled individually if one is lost, which suits workplaces with many users or changing staff. Larger sites often use fobs with networked control.

Can a door entry system link to CCTV and alarms?

Yes. Many systems, especially networked and IP-based ones, integrate with CCTV and alarm systems so entry events and camera footage sit together. Tying them in gives you one joined-up view of security rather than separate systems to check.

Do door entry systems affect fire escape?

They must never prevent safe exit. On escape routes, door releases are generally arranged to fail safe - releasing and allowing people out if the power fails or the fire alarm activates. Controlling entry is the system's job; free, safe exit always takes priority, and any installation should respect the building's fire regulations.