How to Plan a Home Alarm System Yourself — Before You Buy
Before you shop, walk your home and sketch zones, sensor types and a wired-or-wireless plan on paper — so you buy exactly what you need instead of a generic kit. The DIY part is the plan; installation and wiring are often best left to a certified installer.
Planning your alarm system in 4 steps
Walk the house and mark zones
Split the property into PERIMETER (fence line, gates, outbuildings), INTERIOR (rooms, hallways) and, if needed, a 24H zone (like a safe or server room that stays armed even when the rest of the system is disarmed). If part of the house needs to arm independently — a garage, an office wing — mark it as a separate PARTITION.
Pick a sensor type for each spot
Open interior spaces and hallways suit PIR motion detectors; entry doors and windows suit magnetic contacts; rooms with large windows suit glass-break sensors; especially vulnerable points (doors, safes) suit vibration/shock sensors. Avoid aiming a PIR at a pet route, heating vent or a draughty window — that's the most common cause of false alarms.
Decide wired or wireless
A new-build or a renovation with open walls suits wired sensors — no batteries, generally the most tamper-resistant option. A finished home suits wireless sensors instead — but plan for periodic battery replacement, and check the system supports 'supervision' (the panel checking in on each sensor regularly). A mixed design — wired perimeter, wireless interior — is common and perfectly legitimate.
Choose a monitoring path and know the DIY limit
App notifications are cheap but only work if someone actually sees and acts on them. A monitoring station (ARC) gives a guaranteed response for an ongoing subscription. Planning on paper is the DIY part — leave sensor and panel installation, wiring and especially any ARC connection to a certified installer.
What to know before you start planning
The paper plan costs nothing
Zone, sensor and connection choices are thinking work — spending starts only once the plan is finished and clear.
Zones and partitions come before sensors
Split the house into PERIMETER, INTERIOR and, if needed, a 24H zone first, then add a PARTITION if part of the house needs to arm independently — a garage, an office. That way sensor count and placement follow real needs, not a generic bundle.
Sensor type follows the spot, not the other way round
PIR suits open rooms, magnetic contacts suit doors and windows, glass-break suits rooms with large windows, vibration sensors suit doors and safes, outdoor beams or curtain sensors suit a fence line. Always check the exact model and detection range on the manufacturer's datasheet.
Fix the usual false-alarm causes
A PIR aimed at a pet route or a heating vent, a sensor near a draughty window or door, a unit facing direct sunlight or a heat source — these are the most common false-alarm triggers. It's a placement issue, not a sensor-choice one.
Wired or wireless depends on the house
New-build or open walls suit wired sensors with no batteries. A finished home suits wireless instead — plan for periodic battery replacement and confirm the system supports supervision. A mixed setup — wired perimeter, wireless inside — is entirely normal.
App or monitoring station
An app notification is cheap but only works if someone notices it. A monitoring station (ARC) gives a guaranteed response for a subscription fee. Many owners run both — the app for day-to-day awareness, ARC for a guaranteed response.
What to prepare for planning
A short list to fill in BEFORE you go shopping — no tools, no cost.
- {'t': 'A floor plan or sketch', 'd': 'A simple layout of the property — even hand-drawn — showing entry points, windows, garage and anywhere else you want covered.'}
- {'t': 'A walk-through checklist', 'd': 'A note for every room and outdoor point of what you want to detect there — movement, opening, breaking glass or physical impact.'}
- {'t': 'Zones and partitions marked on the plan', 'd': 'PERIMETER and INTERIOR marked out, plus whether you need a 24H zone or a part of the house that arms independently.'}
- {'t': 'A wired-or-wireless note per zone', 'd': 'A mark next to each spot on whether walls are open for cabling or a wireless sensor makes more sense there.'}
- {'t': 'A decision on the monitoring path', 'd': "An early view on whether app notifications are enough or you want an ARC connection, and the point where you'll hand the job to a certified installer."}
Frequently asked questions
Can I install the whole alarm system myself?
Planning it on paper — yes, entirely. Mounting sensors, wiring the panel and especially connecting to a monitoring station (ARC) is often better left to a certified installer, since it affects system reliability and sometimes insurance requirements.
What is EN 50131 and do I need to know it to plan?
EN 50131 is a European standard defining security grades for alarm systems based on risk level. Which grade fits your case depends on a proper risk assessment and often your insurer's requirements — that's confirmed by a certified installer, not decided on this page.
Will a wireless sensor's battery really last for years?
Battery life depends on the specific sensor model and how it's used — always check the manufacturer's datasheet. Reliable systems also use 'supervision', which flags a fault if a sensor stops checking in.
Do I need a monitoring station (ARC)?
Not necessarily — app notifications are enough for many owners, as long as you accept that response depends on someone noticing them. An ARC connection guarantees a response for a subscription fee; many people run both together.
How many sensors do I actually need?
That depends on your specific floor plan and risk assessment — a universal number wouldn't be honest. Start by marking zones and partitions; the sensor count follows from exactly what you want to cover.
Ready to go beyond the paper plan?
Browse specific kits in the shop or book a consultation — we'll help check your plan and connect you with a certified installer if needed.