ButterflyMX, shown here, is the best intercom system.


For over a century, intercom systems have helped us secure buildings and simplify property access. Intercoms have the power to improve both safety and convenience at all kinds of properties. From offices and apartment buildings to gated communities and industrial facilities, any property that requires managed visitor access can benefit from an intercom system.

In this post, we take a deep dive into intercom systems. We discuss what they are, how they work, and what kinds of features and benefits they offer. So, read on to find the answers to all of your questions about intercom systems for buildings.

This guide covers:


best apartment video intercom systems


What is an intercom system?

An intercom system is an electronic device that enables two-way communication between people. Intercom systems also allow people in a building to grant property access to visitors by opening a door or gate remotely.

Intercom systems have taken many forms throughout history. Early intercom systems required people to talk through metal tubing, which carried their voices like two cans connected by a string. But today’s modern electronic intercoms contain circuitry designed to transmit and receive audio and video digitally.

Intercom systems can be used for many applications, but their primary purpose is to enable communication and property access.


Components of an intercom system

Modern intercom systems consist of two components:

  1. A base station
  2. One or more substations

The base station, sometimes called a ‘master station,’ is the main component of an intercom system. It is installed at a property’s entryway.

The base station is connected to one or more substations. Substations are installed at various points throughout the building, such as inside an apartment or office.


Intercom base stations

Intercom system base stations enable visitors outside a building to communicate with visitors inside a building.

As the central piece of an intercom system, the base station controls the entire system. Installed at the property’s entrance, the base station must be connected to power, a door release device, and every substation. You can either hardwire the base station to substations or connect them wirelessly.


The ButterflyMX intercom system base station


Visitors use the base station to notify tenants of their arrival and communicate with any substation in the building.

Pro tip: When purchasing an intercom system, choose one that has a base station with a built-in camera. The camera adds a layer of security and convenience by letting tenants see who’s at the door before letting them in.


Intercom substations

Intercom system substations allow tenants inside the building to communicate with visitors outside the building. They also allow tenants to grant visitors access to the property through a ‘door open’ button.

Traditionally, substations were physical pieces of hardware that included a speaker and a microphone. You would have to install them at various points throughout the building and hardwire them directly to the base station.


intercom system substation


Today, modern intercom systems ditch the substation hardware and instead rely on peoples’ smartphones to act as the intercom substation. Not only does this allow tenants to open the door wherever they are, but it also allows them to see who is at the door through a live video call.

Pro tip: Find an intercom system that uses smartphones as the intercom’s substations. You’ll get more features, including video calls, remote property access, and keyless entry. Plus, you won’t have to pay for additional hardware, wiring, and labor costs to install the intercom substations throughout your building.



Intercom systems consist of two parts: base stations and substations.

Base stations are installed at the entryway of the property and allow visitors to communicate with tenants. Substations are installed at various locations throughout the building and allow tenants to communicate with visitors and grant them access to the building.

Base stations are connected to substations through either a hardwired or a wireless connection. Additionally, intercom systems that use smartphones as their base stations save you money on hardware, wiring, and installation.



  • Install an intercom base station at the entryway of your building.
  • Choose an intercom system with a camera that wirelessly connects to its substations.
  • Smartphones make the best substations because they do not require purchasing and installing additional hardware.


How does an intercom system work?

An intercom system works by allowing visitors to call tenants in a building, then transmitting audio and video signals to substation devices so that tenants and visitors can communicate.

The base station captures audio and video and transmits them to substations. The substations then allow tenants to see and speak with visitors before giving them access to the building. Tenants can remotely unlock the door or gate by pressing a button on their device.


Watch how ButterflyMX works:


How to use an intercom

Here’s a step-by-step guide on how to use an intercom:

  • Use the intercom device at the door or gate to locate the tenant you want to call.
  • Press a button or enter the tenant’s code to call them.
  • The tenant answers the call using their in-unit device, their cell phone, or a landline phone.
  • If the tenant wants to grant access, they press a ‘door open’ button on their intercom device to remotely unlock the door or gate.


What are the types of intercom systems?

There are a wide variety of intercom systems currently available. Some are wireless, while others are wired. Some are designed for apartment use, while commercial intercom systems are intended for commercial buildings.

Here are the nine most common types of intercom systems:

  1. Wireless intercoms
  2. Wired intercoms
  3. Audio intercoms
  4. Video intercoms
  5. Outdoor intercoms
  6. Apartment intercoms
  7. Commercial intercoms
  8. Office intercoms
  9. Gate intercoms


1. Wireless intercoms

When it’s too difficult or expensive to run wiring throughout the property, you can install a wireless intercom system.

Wireless intercoms rely on invisible radio frequencies known as spectrum, which carry the signal that enables all wireless devices to operate. Whether a wireless intercom can transmit audio, video, or both depends on the portion of spectrum used, also known as the ‘band.’ Today’s wireless network providers use low-frequency bands (under 3 GHz), which are also used to transmit the audio and video signals of wireless intercoms.

Pro tip: If you’re considering a wireless intercom system, be sure to ask the intercom provider how the system works. Of course, a direct connection to the internet is best because WiFi signals can be interrupted by external factors like electrical interference. However, if a direct connection is not possible, WiFi or a cellular connection (such as 4/5G) will suffice.

Remember to always test those signals at the location where you’re installing the intercom.


apartment intercom system


2. Wired intercoms

The difference between a wired vs. wireless intercom system is its connection to the internet. All intercoms require some form of wiring — some just require more wiring than others.

Cost-effective building intercom systems only require wiring at the location they’re installed. For example, you’ll need wiring to power your intercom and connect it to your electronic or magnetic door lock.

Other intercoms require wiring throughout the entire building. For example, you might need to run wiring from every substation back to the base station at the property’s entryway.

Pro tip: We recommend connecting your intercom directly to the internet with a Cat 5/6 ethernet cable. Not only will this make your intercom system more secure, but it will also reduce the chance of interference from other wireless devices and electrical signals.


3. Audio intercoms

Sometimes called an apartment buzzer, an audio intercom allows visitors to speak with tenants inside the building. If the audio intercom system also has a door release device, the tenant can grant building access to the visitor. Audio intercoms are commonly only seen in older buildings because video intercom systems have replaced them.

Pro tip: If you’re designing and building a new property, consider a video intercom instead of a buzzer. They’re comparable in price with audio intercoms while providing greater functionality. And if you’re considering replacing your audio intercom, a video intercom is a good alternative. But make sure you have the necessary wiring at the location where the intercom will be installed.


4. Video intercoms

In addition to transmitting audio, some intercoms also transmit video.

Video intercoms require:

  • A camera to capture the video
  • A screen to display it

The ideal video intercom has a built-in camera, but you can also use an external camera. Displaying the video footage requires separate hardware, which you’ll install at various locations throughout the building. Since video requires more bandwidth than audio, it’s best to connect a video intercom directly to the internet.

Pro tip: When purchasing a video intercom for your building, consider a system that sends video calls to smartphones. This allows tenants to see who’s at the door and grant access from anywhere. It also saves you money since you won’t have to purchase and install in-unit hardware.


Watch an overview of the ButterflyMX video intercom systems:


5. Outdoor intercoms

Most properties — especially gated ones — require an outdoor intercom that can withstand the weather year-round. Outdoor intercom systems consist of weatherproof hardware that is installed outside. Visitors use this hardware to contact residents and request property access.

An outdoor intercom’s weatherproofing standards depend on its IP (ingress protection) rating. The best and most durable intercoms are IP65 rated, meaning they’re dust-tight and protected against water projected from a nozzle. So, if you’re installing any intercom hardware outside, choose a system with an IP65 rating.


6. Apartment intercoms

Designed specifically for multifamily buildings, an apartment intercom system is an electronic device that allows two-way communication between apartment residents and their visitors. Apartment intercoms also allow residents to grant property access to their visitors through a door release mechanism.

Apartment intercom systems require two types of hardware:

  1. Master station: Installed at the entrance of the building, an apartment intercom master station allows visitors to find and call tenants from a directory. The intercom master station is wired to power, a door lock, and possibly the internet.
  2. Substations: Residents use an intercom substation installed in their apartment unit to speak with visitors and grant them property access.

Pro tip: Choose an apartment intercom system with a mobile app so your residents can use their smartphone as the substation. That way, residents can see and speak with visitors and grant them access from anywhere, not just their apartment. Besides, purchasing and installing substations in each apartment is expensive due to the hardware, wiring, and labor costs.


7. Commercial intercoms

Commercial intercoms must be able to handle a bit more complexity. In addition to allowing visitors to call an employee inside a multi-tenant building, commercial intercoms must also allow visitors to call the business. This is because a guest might need property access without visiting a specific employee.


office intercom system


For example, a delivery person might be delivering packages to a company in the building without knowing which employee purchased those items. So, when the delivery person uses the commercial intercom in this scenario, there needs to be an option to call the ‘front desk’ or ‘receptionist’.

Pro tip: Make sure your multi-tenant commercial intercom allows visitors to call both the companies in the building and the individual employees of each company. That way, you’ll accommodate every visitor regardless of the reason for their visit.


8. Office intercoms

There are two types of office intercom systems: internal and external.

Internal office intercoms enable communication between parties inside an office building, such as employees or coworkers. You can think of them as walkie-talkies, allowing people in different rooms to easily speak with each other.

External office intercom systems enable communication between people in the office and people outside the building (like visitors and delivery people). External office intercoms also include a door release device to allow for property access.

Pro tip: Internal office intercom systems are no longer used because they have been replaced by smartphones, emails, and messaging apps. If you’re looking for an office intercom, you’re probably looking for a commercial intercom system for your business or office building. Commercial intercom systems are necessary for all multi-tenant office buildings.


9. Gate intercoms

At many properties, the front entrance isn’t a door — it’s a gate. A gate intercom system can be used to grant access to cars or pedestrians.

Gate intercom systems are often installed at:

  • Gated communities
  • Industrial properties
  • Parking garage entrances
  • Campgrounds

Just like other intercom systems, a gate intercom requires a master station and substations so that people on the property can speak to visitors seeking access and open the gate for them.


Gate Intercom System


Gate intercoms may include a call button that dials a substation controlled by property staff. This could be a leasing agent, a gate attendant, a front desk, or any other representative of the property.

Gate intercom systems can be trickier to install because the location of the gate may not be near a building or other structure with a power supply. So, you may need to run wiring a great distance to power it. The location of the gate on the property will dictate the cost and complexity of the installation.

Pro tip: If you’re buying an intercom for a gate, choose a system that only requires three connections: power, internet, and the gate opener. A system that requires wiring between the base station and every substation is more difficult and expensive to install.



While the basic structure of an intercom always remains the same (a base station with master stations), there are several variations of intercom systems.

Some intercoms require wiring between the base station and every master station, while others operate wirelessly. Intercoms can also offer audio communication only (buzzer systems) or audio and video communication (video intercoms).

Intercom systems improve property access for a wide variety of properties. Any property with an entrance that requires managed access will benefit from an intercom system.

You can install an intercom system at:

  • Commercial properties (like offices, buildings for non-profit organizations, and industrial properties)
  • Residential properties (like apartment buildings, gated communities, and mobile home parks)



  • To choose the right intercom system, consider the type of property (residential vs. commercial) and the type of entryway (door vs. gate) where you’re installing the intercom.
  • Instead of an audio intercom, choose a video intercom system so that tenants can see visitors before granting them property access.
  • Opt for an intercom that’s both vandal-resistant and weatherproof.
  • To reduce installation costs, choose a wireless intercom that doesn’t require wiring throughout the property.
  • For security and performance, choose an intercom system with a wired connection to the internet.
  • Increase curb appeal with an alluring intercom that combines beauty and function.
  • Opt for an intercom system that accepts multiple credentials, such as opening from a smartphone, key cards and fobs, and RFID compatibility.
  • The best video intercom system for any property is one that connects to an entire suite of access control products for holistic security.


Intercom system installation

The complexity and cost of replacing or installing an intercom system depend on three things:

  • The type of intercom
  • The wiring
  • Location of the install

If you’re installing a video intercom with substations in each apartment unit, the installation will be more complicated and more expensive. Purchasing all the hardware and running wiring to each apartment adds up. However, if you’re installing a wireless intercom that sends signals to a tenant’s smartphone, the installation will cost less.

Where you install the intercom system matters too. If you’re replacing an existing intercom system with the wiring and backbox already in place, the installation will be easier and less expensive. But if you need to cut open a wall or break apart some bricks at an industrial complex, expect the installation to be more difficult and costly.

Pro tip: Installing an intercom system is often more expensive than the intercom itself. The cost of additional parts, wiring, and labor add up quickly. To ensure you’re not paying more than you have to, get a quote from several certified installers in your area. This way, you can compare their quotes and determine which is right for you.


How much does an intercom system cost?

An intercom system ranges in price from $500 to $5000, and sometimes more depending on its features and functionality. This cost range from inexpensive to luxury does not include ongoing maintenance or servicing of the intercom system, which can include upgrades, replacement parts, or additional fees.


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Jeff Granger

I'm a native Texan and tech guru who is fascinated by technology's impact on the real estate industry.