New Home Security Checklist: The First Week, the First Month, and the System Decision

The first week is about invalidating other people's access: rekey or replace every exterior lock, reset garage remotes and keypads, and change the codes on any alarm or smart device the sellers left behind. The first month is about the building itself: door and window hardware, lighting, and testing whatever equipment conveyed with the house. Only then decide on a security system, once you know how the house actually gets used. The ordering matters because keys and codes are the cheapest risk to eliminate and the one previous occupants demonstrably hold.

Figures researched 2026-08-19; each source below carries its access date. Prices change; treat any price here as "as of" its date.

The first week: invalidate old access

When you close on a house, an unknown number of keys, codes, and remotes remain in other hands: previous owners, their relatives, cleaners, dog walkers, contractors, and every agent who accessed the lockbox. This is not hypothetical risk; in Bureau of Justice Statistics burglary data, nearly 4 percent of unlawful-entry burglaries where a resident was present involved an offender who used a key to get in. The fixes are cheap and fast:

Rekey or replace every exterior lock. Rekeying (a locksmith changes the pins so old keys stop working) is the budget option; full replacement makes sense if the hardware is worn or you want to upgrade to higher-security cylinders or smart locks anyway. Count every door: front, back, garage side door, basement, and any outbuilding sharing a key.

Reset the garage. Clear the opener's memory of all paired remotes and re-pair only your own, and change the keypad code. Garage openers are the most commonly forgotten access path in a handover, and the garage often has an unlocked door into the house.

Change every code that conveyed. Alarm panel master and user codes, smart lock codes, gate codes, Wi-Fi router admin password if the router stayed. If a previously monitored alarm remains installed, call the provider: accounts do not transfer automatically, and an alarm tied to the seller's account is doing nothing for you.

Walk the perimeter once with fresh eyes. Note every ground-level window latch, the state of exterior lighting, where the water and electrical shutoffs are, and which door you would break into if you locked yourself out; that door is your weakest point, and it deserves the best hardware.

Test life-safety devices now, not eventually. Press the test button on every smoke and CO alarm and replace batteries or expired units immediately. This outranks every security task on this page, and it is a ten-minute job.

The first month: harden the building and learn what you inherited

Doors first. BJS burglary data identifies damaging or removing a door as the most common method in forcible-entry burglaries, which is why door hardware is the highest-yield hardening spend. The standard upgrades: a solid or metal-clad exterior door where a hollow one exists, deadbolts on every exterior door, and reinforced strike plates with 3-inch screws that reach the framing rather than the trim. The same door-hardening logic covered in our apartment door security checklist applies to houses, minus the landlord constraints.

Windows second. Confirm every accessible window locks and actually latches (paint and settling defeat many), and add inexpensive secondary locks or pin stops to ground-floor and basement windows. Clear shrubbery that screens windows from the street; concealment is a burglar's friend, and trimming it is free.

Lighting and sightlines. Motion lighting at every approach, dusk-to-dawn fixtures at doors used after dark. While you are at it, decide what a passerby can see from the sidewalk: unpacked-box mountains visible through windows advertise both new occupancy and new electronics.

Inventory what the sellers left. Cameras, doorbells, sensors, panels: factory-reset anything that stays (otherwise the previous owner may retain app access to cameras inside your house, which is reason enough to reset before first use), and evaluate whether the hardware is worth keeping. An inherited wired panel can often be taken over by a new monitoring provider; ask providers directly, since takeover support varies by panel.

Document your property. Photograph serial numbers of electronics, tools, and bikes as you unpack; it takes minutes during a move and is painful to reconstruct later for police reports or insurance.

Then, and only then, the system decision

Buying a security system during closing week is how people overbuy: you do not yet know which doors you actually use, where packages pile up, or what the neighborhood's real patterns are. After a few weeks you will, and the decision gets cheaper and better.

The decision tree is short. First, DIY or professionally installed; the cost logic is laid out in DIY vs professional monitoring cost. Second, monitored or self-monitored: is professional monitoring worth it covers the honest math, and the short version is that monitoring buys dispatch when you cannot respond yourself, which matters most for households that travel, sleep deep, or leave the house empty on predictable schedules. Third, the budget envelope: realistic equipment and monthly ranges are in home security cost per month.

A new home is also the one moment insurance paperwork is already open: many insurers discount premiums for monitored systems, so ask yours what qualifies and what documentation they want before you choose a provider, not after.

If you land on wanting professional monitoring quotes, our quote tool takes a short questionnaire about the house and pulls quotes from monitoring providers, which is a faster path than repeating your details across sales calls. Either way, the sequence stands: locks and codes in week one, the building in month one, the system when you know the house.

Frequently asked questions

Should I rekey even if the sellers handed over all their keys?
Yes. You cannot verify 'all': copies made for relatives, cleaners, and contractors over the years do not come back at closing, and BJS data shows a measurable share of unlawful-entry burglaries with a resident present involve an offender using a key. Rekeying is cheap insurance against an unauditable risk.
The house came with an alarm system. Can I just use it?
Often, but not as-is. Factory-reset any cameras or smart devices before trusting them, change all panel codes, and contact a monitoring provider about taking over the panel, since the seller's monitoring account does not transfer. Wired panel takeover support varies by provider and panel, so ask before assuming the hardware is usable.
What is the single best security upgrade for a new house?
Door hardware. Damaging or removing a door is the most common forcible-entry method in BJS burglary data, and reinforced strike plates with long screws, solid doors, and quality deadbolts are one-time costs that work with no batteries, apps, or subscriptions.
How fast do I need a full security system?
Less fast than the sales calls imply. Locks, codes, lighting, and window latches close the urgent gaps in week one for modest cost. A few weeks of living in the house makes the system decision better informed: you will know the real entry points, package patterns, and whether monitoring fits how the household runs.
Does a security system lower home insurance?
Many insurers offer discounts for monitored systems, with size and qualifying criteria varying by insurer and policy. Ask your insurer what qualifies and what proof they require (often a monitoring certificate) before selecting a provider, so the discount informs the choice rather than arriving as an afterthought.

Sources

  1. Nearly 4 percent of unlawful entry burglaries with a resident present involved an offender who had and used a key; damaging or removing a door was the most common entry type in forcible and attempted forcible entry burglaries (BJS, Victimization During Household Burglary, 2003-2007 data): https://bjs.ojp.gov/press-release/victimization-during-household-burglary (accessed 2026-08-19)