Buyer's Guide · 8 min read
Wired vs Wireless Alarm Systems: Which Is Right for Your Property?
Choosing between a traditional wired alarm and a modern wireless system like Ajax is the single biggest decision you'll make when securing your home or business. Here's an honest, engineer-led breakdown of how they compare on installation, reliability, and long-term cost — and why Ajax's Jeweller radio protocol has changed what "wireless" means in security.
The short answer
For 95% of UK homes and small-to-medium businesses, a professionally installed Ajax wireless system is faster to fit, more reliable in daily use, cheaper over its lifetime, and easier to expand than a wired equivalent. Wired systems still have a niche in very large-scale commercial builds where cabling is already in place.
Side-by-side comparison
| Factor | Wired | Ajax Wireless |
|---|---|---|
| Install time (3-bed home) | 2–4 days | 4–6 hours |
| Wall / decoration damage | Significant (chasing cable) | None |
| Battery life per device | N/A (mains) | Up to 7 years |
| Radio range (open air) | N/A | Up to 2,000 m (Jeweller) |
| False alarm rate | Moderate | Very low (verified signals) |
| Expandable after install | Difficult | Add a device in minutes |
| Works during power cut | Backup battery only | Yes + 4G/LTE backup |
| Typical lifetime cost | Higher (labour + repairs) | Lower |
1. Installation speed
Wired systems require an engineer to run low-voltage cable from every sensor back to a central control panel. In an occupied home that means lifting floorboards, chasing plaster, and redecorating — typically 2–4 days of disruption. Ajax devices talk to the hub over the Jeweller radio protocol, so a full home fit is usually completed in a single morning with zero mess.
2. Reliability — the Jeweller advantage
The historic argument for wired was "it can't be jammed." That's no longer true. Ajax's Jeweller two-way radio protocol polls every device every 12–36 seconds, hops across frequencies to defeat jamming attempts, and encrypts every packet. Any lost signal triggers a tamper alert on your phone within seconds. In independent testing Ajax reports a 99.99% signal reliability at ranges up to 2,000 metres in open air — figures a cabled loop simply cannot self-diagnose.
Wired systems also share a single point of failure: cut the cable, kill the zone. Ajax hubs run on mains with a backup battery and optional 4G/LTE, so the system stays online through power cuts and broadband outages.
3. Cost-effectiveness over 10 years
Wired kit is cheaper per sensor, but labour dominates the invoice — often 60–70% of a wired install. Ajax sensors run on lithium batteries lasting up to seven years, so the only ongoing cost is a battery swap. Add the fact that expansion (a new sensor, a garage door contact, an outdoor siren) takes minutes rather than another cabling day, and Ajax typically comes out 20–35% cheaper over a decade.
When wired still makes sense
- New-build commercial sites where cable trays are already going in.
- Very large industrial estates > 2 km across a single perimeter.
- Insurance schedules that still specify Grade 3 wired equipment (increasingly rare — Ajax is EN 50131 Grade 2/3 certified).
Our verdict
For every home, retail unit, office, and HMO we install across Edinburgh and central Scotland, we specify Ajax. It's faster, cleaner, more reliable in daily service, and demonstrably cheaper to own — without any of the compromises the word "wireless" used to imply.
Get an engineer's opinion on your property
Free, no-obligation site survey across Edinburgh and central Scotland.