What are the main types of building intercom?
Building intercoms fall into three broad groups. They differ in how the entry panel talks to the people answering, which drives cost, flexibility and how well they suit your building.
| Type | How it connects | Typically suits | Watch for |
|---|---|---|---|
| Wired (analogue or two-wire) | Dedicated cabling from the entry panel to a handset or monitor in each unit | Existing apartment blocks with sound cabling; simple office entries | Limited app answering on older systems; spare parts for ageing models |
| IP (network) intercom | Runs over data cabling and the building network, often with PoE power | New builds, larger apartment buildings, commercial and mixed-use sites | Needs a properly designed, secured network and power backup |
| 4G cellular ("wireless") | A SIM in the entry panel calls residents' or staff mobiles over the mobile network | Gates, car parks, small blocks and sites where trenching or cabling is costly | Mobile coverage at the panel, call costs and SIM plans, 4G voice support |
Many buildings end up with a mix: an IP or two-wire system for the lobby and units, and a 4G unit on a remote vehicle gate.
Is a wireless apartment intercom a good idea?
"Wireless" usually means one of two things. A cellular intercom has its own SIM and rings residents' mobile phones, so no cable is needed between the entry panel and the units. A Wi-Fi or cloud intercom still needs power and a network at the panel, but answers on an app instead of a wired handset.
Cellular intercoms work well for gates, car park entries and small buildings, and they avoid cable runs through common property. For a larger apartment block, they are usually not the best main system: every call depends on mobile coverage at the panel and on residents' phones, there is an ongoing SIM plan, and you lose in-unit monitors for residents who want them. Most larger buildings are better served by IP or two-wire for the main entry, with app answering added on top.
What did the 3G shutdown change for intercoms?
New Zealand's mobile networks have closed their 3G services. According to the NZ Telecommunications Forum, 2degrees switched off 3G between December 2025 and February 2026, One NZ shut down both its 2G and 3G networks between January and March 2026, and Spark completed its shutdown on 31 March 2026. The TCF is clear that devices relying on 3G in any way no longer work, and lists security alarms and other business devices alongside phones.
For buildings, that means any GSM gate or door intercom, dial-to-open gate controller or alarm communicator that used a 3G module has stopped working. The gate or door hardware itself usually still works; it is the call, SMS or app function that has gone. When RNZ reported on gate systems in 2025, a gate supplier noted that remotes and keypads keep working and only mobile-based functions are affected, while the TCF said some products only need a new communications module and others need replacing completely because the module is built in.
When you replace a 3G unit, ask for a 4G model approved for NZ networks that supports 4G voice calling (VoLTE). The TCF warns that some 4G devices still relied on 3G for voice calls, and One NZ helped customers switch on 4G calling before the shutdown. Also check the SIM is 4G-capable.
Does the copper landline switch-off affect intercoms?
It can. Some older entry systems, lift phones and alarm diallers call out over a copper phone line. Chorus says it will retire all copper services in fibre areas by the end of 2026 and plans to retire copper nationwide by 2028. If your intercom dials out over a landline, it will need to move to a fibre-based voice service, an IP connection or a 4G unit. Chorus also points out that services over fibre do not work in a power cut without a battery backup, so plan a UPS for anything the building relies on.
How should an intercom work with access control?
An intercom is most useful when it is designed with the rest of the entry, not bolted on later. For apartments and commercial buildings that usually means:
- Door and gate release through the access control system, so every remote unlock is logged against the door and the time.
- Residents and staff use a card, fob or phone credential at the same entry, so the intercom is only for visitors and deliveries.
- Lift control, so a visitor let in by unit 504 can only reach level 5.
- Call video kept with your CCTV, under the same retention and access rules (see our CCTV and Privacy Act guide).
- Safe exit. If the released door is on an escape route, it is usually part of the building's compliance schedule as an access-controlled door. See our guide to access-controlled doors on escape routes.
We cover the hardware side on our access control, gates and barriers and intercom pages.
What should a body corporate ask for when upgrading an intercom?
Under the Unit Titles Act, the body corporate maintains the common property and the parts of the building that serve more than one unit, and must have a long-term maintenance plan. An entry intercom is a typical shared asset, so it helps to treat the upgrade as a planned item rather than an emergency repair. Before you approve a quote, ask:
- Can the existing cabling be reused? A survey should confirm whether a two-wire or IP-over-existing-cable upgrade is possible before anyone proposes recabling every unit.
- How do residents answer? In-unit monitor, mobile app, or both, and what happens for residents who do not want an app.
- Is there any 3G, 2G or copper dependency left? Ask for it in writing, including on gates and lift phones.
- How does it link to access control and lifts, and who can see the logs?
- What are the ongoing costs? SIM plans, cloud or app subscriptions and support, quoted separately from the install.
- Who manages the directory when tenants and owners change, and how quickly can a building manager do it?
- What happens in a power or network outage? Battery backup, and how the door behaves.
- Can it be staged? Lobby panel and common areas first, units over time, if the budget needs it.
For commercial buildings and property portfolios, add one more: can the same platform be used across your other sites, so your facility or property managers are not juggling a different system in every building.
How Com4 can help
Com4 has been installing commercial security in Auckland since 2011, as Com4 since 2023, and holds PSPLA licence 25-128630. We survey existing intercoms, check what cabling and hardware can be reused, find any 3G or copper dependencies, and design the intercom together with access control, gates and CCTV. We work with body corporates and shared buildings and commercial and industrial sites across Auckland, from the CBD to Albany and the North Shore, Penrose and East Tāmaki. Call 0800 266 444 or use the form below.
Frequently asked questions
Will my old GSM gate intercom still work?
What is the best intercom for an apartment building?
Can we keep our existing intercom cabling?
Do 4G intercoms need a SIM plan?
Does an intercom-released door need to be on the compliance schedule?
Sources
- NZ Telecommunications Forum, 3G shutdown complete nationwide (2 April 2026)
- NZ Telecommunications Forum, Understanding the 3G shutdown
- One NZ, One NZ completes 2G and 3G mobile network shutdown (23 March 2026)
- RNZ, Homes gates, security systems affected by 3G shutdown (28 May 2025)
- Chorus, Copper retirement and Landlines and alarms
- Unit Titles Services (MBIE), Unit title maintenance
This guide is general information. Check product compatibility with the manufacturer and your mobile provider before you buy.