A door entry system lets you screen visitors before letting them in — without leaving your flat or office. Here's how the different types work and which is right for your building.
What Is a Door Entry System?
A door entry system (also called an intercom or door buzzer system) allows occupants of a building to communicate with visitors at the entrance and remotely release the door lock — without physically going downstairs or to the front door.
At its simplest, this is an audio-only intercom with an electric door release (a small electromagnetic lock or electric strike that releases when a button is pressed). At the more advanced end, it includes HD cameras, video screens, smartphone integration, and connection to access control systems.
Types of Door Entry System
- Audio-only intercom — A visitor presses a button, a buzzer sounds in the flat or office, the occupant picks up a handset and speaks to the visitor, then presses a button to release the door. Simple, reliable, and the most common type in older residential blocks.
- Video door entry — Works the same way but adds a camera at the entrance and a screen (or monitor) in each flat. The occupant can see the visitor before deciding whether to let them in. Increasingly the standard in new-build blocks and converted properties.
- App-connected / smart door entry — The video feed and door release are accessible via a smartphone app. This means you can answer the door from anywhere in the world — useful for landlords, Airbnb hosts, or busy office managers.
- Combined access control and door entry — A fob or key card reader at the entrance plus an intercom panel. Residents use their fob for day-to-day access; visitors use the intercom button to call up.
What Is an Electric Strike or Magnetic Lock?
The electronic door release is the mechanism that lets you unlock the door remotely. An electric strike replaces the fixed strike plate in the door frame — when power is applied, the latch is free to move and the door can be pushed open. A magnetic lock (magloc) uses an electromagnet to hold the door closed; cutting power releases it.
For fire safety, magnetic locks must be connected to the building's fire alarm system so they release automatically in the event of an evacuation.
Who Needs a Door Entry System?
Door entry systems are standard in blocks of flats, apartment conversions, offices, and any building with a shared entrance that needs to be secured. For HMO landlords, a door entry system on the communal entrance adds a layer of security that tenants genuinely appreciate and that insurers look favourably on.
Security Red Alert designs and installs audio, video, and app-connected door entry systems across London. We handle everything from wiring to programming to tenant handover. Contact us for a free site survey.
Need help with this in London?
Security Red Alert covers all 32 London boroughs from our Summerstown SW17 office. Explore our Access Control & Door Entry and Commercial Security services, or call 020 8946 5567 for a free survey.