Anatomy of a Complete Home Security System for Greenwich CT (2026)

A complete Greenwich CT home security system in 2026 includes (1) a professional alarm panel with door/window/motion sensors, (2) 6–12 4K PoE cameras with NVR storage, (3) UL-listed 24/7 central station monitoring with cellular backup, (4) smart locks and access control at primary entries, (5) environmental sensors for freeze, water, smoke, and CO, and (6) integration with Apple Home, Google Home, or Alexa for unified scenes. Total installed cost runs $8,500–$22,000 for a typical 3,500–5,500 sq ft Greenwich home, plus $35–$80/month for monitoring. Insurance discounts of 10–25% on Greenwich-tier policies typically offset 30–60% of total annual cost.

"Home security" sold by national chains usually means one or two of these layers. A real system covers all six.

Each layer addresses a different threat and contributes a different category of evidence or response:

• Alarm panel + sensors — the legal definition of a "monitored alarm." Detects entry and motion; triggers central station response.
• Cameras + NVR — the forensics layer. Doesn't prevent intrusion; provides evidence and live verification.
• Professional monitoring — the response layer. Police, fire, and medical dispatch on confirmed events. Required for full insurance credits.
• Smart locks + access — the access control layer. Who comes in, when, and with what credentials.
• Environmental + life safety — the silent-disaster layer. Frozen pipes, water leaks, smoke, CO. Often the source of larger insurance claims than burglary.
• Integration — the layer that turns the previous five into a single system instead of five competing apps

Skip any layer and the others can't fully compensate. Cameras without an alarm dispatch nobody. An alarm without environmental sensors misses frozen pipes. Smart locks without integration are just a luxury keypad.

The alarm panel is the brain of the security system. Component specifics:

• Panel — Honeywell ProSeries (ProA7Plus), Qolsys IQ Panel 4, or Resideo Vista. Cellular-primary with Wi-Fi backup; 24-hour battery backup minimum.
• Door/window contacts — every operable exterior door and ground-level window. Recessed contacts for new construction, surface-mount for retrofits. $20–$60 per sensor installed.
• Motion sensors — passive infrared (PIR) in main hallways, mudroom, basement entries. Pet-immune up to 80 lbs. $40–$120 each installed.
• Glass-break sensors — in rooms with large windows (living rooms, sunrooms). Listens for the specific frequency signature of breaking glass. $80–$150 each installed.
• Keypads — primary entries; touchscreen panels at the kitchen / family room. Z-Wave keypads for secondary entries.
• Panic buttons — bedside, primary suite, optional throughout. Direct silent dispatch to police.

For a typical 3,500–5,500 sq ft Greenwich home: 12–25 sensors, 1–3 keypads, 1 panel. Hardware $1,800–$4,500 plus install $1,500–$3,000.

Cameras don't prevent intrusion — they provide the evidence and verification that turn an alarm event into a meaningful response.

• 4K PoE perimeter cameras — Hikvision ColorVu, Dahua Pro, or Axis at all four sides of the home, plus driveway and key chokepoints. 6–12 cameras typical for 3,500–5,500 sq ft.
• Doorbell camera — Hikvision, Lockly, or Ring at the main entry. Two-way audio for delivery confirmation.
• Network Video Recorder (NVR) — local storage with 30–90 day retention. No monthly cloud fee. See our best NVR systems guide and NVR vs cloud comparison.
• License plate camera (optional) — at the driveway entry or gate for properties with long approaches. See our LPR guide.
• Discreet interior cameras (optional) — main hallway, mechanical room, kitchen. Always with privacy switch and clearly documented for guests.

Hardware $4,000–$9,000; install $2,500–$5,000. For coastal Greenwich properties (Belle Haven, Riverside), specify marine-rated cameras per our waterfront cameras guide.

Monitoring is what turns "alarm went off" into "police are en route." Self-monitoring works for primary residences with active homeowners; for Greenwich-tier properties and second homes, professional monitoring is non-negotiable.

• UL-listed central station — meets the Underwriters Laboratories standard for alarm monitoring. Required for many high-value insurance programs.
• Cellular backup communication — alarm panel includes a cellular module that works when cable internet is down. Verizon and AT&T paths typical.
• Video verification — when an alarm triggers, monitoring agents pull live camera feeds to confirm intrusion before dispatching, dramatically reducing false-alarm fines
• Two-way voice — monitoring agents can speak through the keypad or panel speaker to confirm or de-escalate
• Multiple call lists — primary, spouse, property manager, neighbor
• No-contract options — most reputable local installers (us included) offer month-to-month monitoring at $35–$80/mo

Greenwich requires alarm permit registration; see our Greenwich alarm permit guide for the exact process and false-alarm rules.

Smart locks turn the security system from "react to intrusion" to "control who enters in the first place."

• Smart deadbolts on all primary entries — Schlage Encode Plus, Yale Assure 2, Aqara U200. See our smart lock buyer's guide.
• Unique codes per person — family, housekeeper, contractors, dog walker, deliveries. Each with schedule and expiration.
• Garage door integration — smart garage controllers (Chamberlain MyQ, Aladdin Connect) integrate into the alarm panel
• Driveway gate (where applicable) — keypad, intercom, and optional LPR for automated entry
• Access logs — every entry timestamped and tied to the credential used. Critical for auditing and incident investigation.

Hardware $1,500–$4,000; install $500–$1,500. Smart locks are also one of the highest-ROI single upgrades a Greenwich homeowner can make in terms of daily quality of life.

The layer most often missed by national chains and DIY systems. Often the layer that produces the largest insurance claim category in Greenwich:

• Smoke and CO detectors — interconnected, monitored, with cellular dispatch. Standard battery smokes don't get monitoring response.
• Freeze sensors — basement, attic, garage, exterior-wall bathrooms. Trigger at 45°F before pipes freeze.
• Water leak sensors — under every sink, dishwasher, washing machine, water heater, ice maker line. $25–$75 each.
• Whole-home water shutoff — Moen Flo or Phyn integrate with leak sensors and automatically shut off the main water line. Often qualifies for separate insurance credit.
• Sump pump monitoring — high-water and pump-current sensors
• Glass break and impact (storm preparation) — for Greenwich shoreline homes during nor'easters and hurricanes

For unoccupied or second-home Greenwich properties, this layer matters more than cameras. See our vacation home security guide.

Five separate apps for five layers means nobody checks any of them. Integration ties everything into one coherent system:

• One unified app — Alarm.com, Honeywell Total Connect, or a Hikvision/Lutron integration platform
• Goodnight scene — single tap arms alarm, locks doors, lowers shades, sets back thermostat, turns off lights
• Welcome home scene — authorized smart-lock unlock disarms alarm, ramps up lights, returns thermostat to comfort
• Vacation/away scene — geofence detects nobody home, raises sensitivity, randomizes lights on schedule, lowers shades
• Camera-triggered automation — exterior motion at night triggers landscape lighting and pre-roll recording
• Voice control via Apple Home, Google Home, or Alexa — see our HomeKit and Google Home guide

The best installs are invisible — the system feels like a home that just behaves correctly, not a collection of devices that need management.

Three reference configurations:

Compact (2,000–3,000 sq ft starter home):

• 10–15 alarm sensors, 4–6 cameras, 4 environmental sensors, 1–2 smart locks
• Hardware: $4,500–$7,500 / Install: $2,500–$4,500 / Monitoring: $35–$45/mo
• Total: $7,000–$12,000 installed

Standard (3,500–5,500 sq ft Greenwich home):

• 20–30 alarm sensors, 8–12 cameras, 8–12 environmental sensors, 3–4 smart locks, water shutoff
• Hardware: $9,000–$14,000 / Install: $4,500–$8,000 / Monitoring: $50–$70/mo
• Total: $13,500–$22,000 installed

Estate (6,000+ sq ft, gated, multi-building):

• 40+ alarm sensors, 16–32 cameras, full environmental, gate + LPR, multi-zone access control, generator-backed
• Hardware: $25,000–$60,000 / Install: $12,000–$30,000 / Monitoring: $80–$200/mo
• Total: $40,000–$95,000+ installed

For detailed pricing, see our Greenwich camera installation cost guide.

A complete system doesn't have to happen all at once. The right phasing for most Greenwich homeowners:

1. Phase 1 — Foundation (Day 1): Alarm panel + sensors + monitoring + 1 smart lock + smoke/CO. Gets you covered immediately. ~$5,000–$8,000.
2. Phase 2 — Cameras (Weeks 2–6): 6–12 PoE cameras + NVR. Adds forensics layer and remote view. ~$6,000–$12,000.
3. Phase 3 — Environmental (Weeks 4–8): Freeze sensors + water leak sensors + whole-home water shutoff. Lowest-cost, highest-ROI layer. ~$1,500–$3,500.
4. Phase 4 — Smart access expansion (Weeks 8–12): remaining smart locks, garage integration, gate (if applicable). ~$2,000–$8,000.
5. Phase 5 — Integration polish (Weeks 12+): scenes, voice control, geofencing, refinement based on actual usage

Most Greenwich homeowners reach a "complete" system within 6–10 weeks of Phase 1.

The fastest path to a real system is a free 60-minute on-site walkthrough. We map all six layers against your specific home, give you a phased proposal, and don't push hardware you don't need.

• Book a free Greenwich security walkthrough
• Call (914) 247-9506
• Explore Greenwich home security services
• Read related: best cameras for Greenwich, installation cost guide, alarm permit guide, and smart home setup for luxury homes

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