Intercom Replacement Costs: Upgrading Old Door Entry Systems

The decision tree replacement surveys walk

• Step 1 — riser autopsy: existing pairs tested flat-by-flat (the faults guide's triage formalised) — sound wiring is inherited capital worth £100+/flat in avoided labour
• Step 2 — failure pattern reading: handset-era problems (reusable wiring, replace ends) vs riser corrosion (wiring's done — architecture choice opens) vs panel/PSU death (sometimes repair beats any replacement — honesty checkpoint)
• Step 3 — architecture menu against budget/appetite: like-for-like audio (cheapest, least change), 2-wire video over surviving pairs (the value upgrade of the decade — monitors without rewiring), GSM (no flat access, future-proof against line switch-offs, the retrofit king per its guide), full IP (refurb-grade results, refurb-grade access requirements)
• Step 4 — bundling audit: entrance door hardware age, fob system candidacy (DESFire upgrade in the same visit — the flats fob logic), CCTV at entrance (shared labour again) — replacement visits that touch one system per decade waste scaffolding, metaphorical and real
• Step 5 — consultation packaging: Section 20-ready option quotes (the agents' procurement section in the flats cost guide)

Cost benchmarks by scenario

Real-block figures from our replacement work: 8-flat conversion, analogue audio dead, wiring corroded → GSM video: £2,200 installed, no flat visits, two weeks order-to-working. 16-flat 1980s block, wiring sound, handsets dying piecemeal → 2-wire video (Comelit-class): £5,500 (£345/flat) including new entrance panel and lock work, monitors fitted by appointment over two days. 30-flat estate block, full refurb under way → IP video integrated with new fob access: £14,000 across the project at fit-out economics. Like-for-like audio floors: 10-flat handset/panel refresh on good wiring: £1,800–£2,500. The pattern: wiring's survival swings per-flat costs ±£150, and bundling fob/CCTV moves combined-project value more than any brand choice (the brands guide stays second-order, as it argued).

Phasing, residents and the switch-off deadline

Replacement execution realities: phased paths exist (entrance panel + GSM core now, monitor offers per-flat later — hybrid systems carry mixed interfaces gracefully), resident communication decides timelines more than engineering (flat-access projects need notice cycles, vulnerable-resident provisions, and the agent's letter doing its job — we template these), and the analogue switch-off back-stops procrastination for dialler-dependent systems (dead-by-default approaches; the switch-off guide's migration urgency applies to every phone-line-touching intercom — audit yours this quarter). Maintenance handover completes replacements properly: programming records, spare credentials process, £150–£400/yr cover — the difference between a system that ages and one that's abandoned. Fifteen-year assets deserve fifteen-minute annual thought; we structure exactly that.