Replacing a Legacy Multi-Tenant Intercom System

Planning a move from a legacy intercom to DoorBird

Many multi-tenant properties are still running an older intercom system — a wired analog panel tied to individual unit phones, or a proprietary system from a manufacturer that's since discontinued support. Replacing that kind of system with an IP-based platform like DoorBird is a worthwhile upgrade for a lot of properties, but it's an infrastructure project, not a drop-in swap. Planning the wiring, power, and resident transition up front will save a lot of headaches during installation.

Start with an honest audit of what's there now

Before assuming anything about compatibility, have a qualified installer document the existing system in detail:

• What type of system it is — a shared bus wired to every unit, a simple point-to-point pair per unit, or something proprietary to the original manufacturer
• How the entry door or gate release is wired and powered — what triggers it, what voltage and current it expects, and where that power currently originates
• Condition of existing conduit and cabling — age, wire gauge, number of conductors, and whether it's actually accessible for reuse or fished through inaccessible walls
• Physical mounting — back-box dimensions and depth at the entry station and at any in-unit stations, since a new station's footprint may not match the old one

Don't assume existing wiring is compatible with a new IP-based system just because it currently carries intercom signal. Legacy multi-tenant intercom wiring is often built around a bus topology or wiring standard that doesn't carry Ethernet or PoE, and confirming compatibility — or planning for new low-voltage cabling — should happen before installation day, not during it.

Power and network readiness

An IP intercom station is a networked device, which means the building's network infrastructure needs to be ready to support it, not just the door hardware. Plan for:

• A network connection reaching each entry station, along with a power source for it — commonly delivered via Power over Ethernet, though exact requirements depend on the specific hardware, so confirm against that product's datasheet
• Sufficient switch capacity and, if the property spans multiple buildings or entry points, a plan for how those locations connect back to shared network infrastructure
• A decision on how the system will be reachable for remote administration and for residents' calls to route off-site, which your installer or IT contact can help scope for your specific network setup

Planning the resident transition

The technical cutover is only half the project — residents need to be brought along too:

• Notify residents well ahead of the change, including what will look and feel different at the entry point
• Collect or confirm each resident's contact information and preferred device ahead of time, so their directory entry is ready before the new system goes live
• Decide whether the legacy system will stay operational in parallel through a transition window, or whether cutover will happen all at once — a parallel period reduces risk but requires both systems to be functional simultaneously
• Plan a simple way for residents to get help during the first few weeks, since a change to how visitors reach them is one of the more noticeable changes in daily building life
• Update your move-in and move-out procedures so new residents are added to the new system's directory correctly going forward

After cutover

Once the new system is live, confirm someone on your team owns ongoing administration — maintaining the directory, handling access requests, and keeping firmware and app versions current. Decommission the legacy system's wiring and hardware according to your installer's guidance rather than leaving it live and unmaintained alongside the new one.

Still need help?

If you're planning a replacement project and want help thinking through your specific building's wiring or transition plan, submit a support ticket and our team can walk through it with you.