Home Security During Renovation: Why Break-Ins Spike and What to Do About It

You've spent months planning your extension. You've got a builder you trust, a budget, and a start date. What most homeowners don't plan for is what happens to their home's security the moment the scaffolding goes up.

A renovation site is not a secure home. And thieves know it.

Why Renovations Attract Thieves

Your home sits in its most vulnerable state during a build. Several things happen simultaneously that opportunist burglars actively look for:

Scaffolding = a free ladder

Scaffolding that runs to roof level gives anyone prepared to climb easy access to first-floor windows and even the roof itself. Scaffolding companies erect it for access — but it works both ways. Overnight, when the site is empty, it's an open invitation.

Temporary boarding is not the same as a door

When an extension is being built, rear walls come down, doors are removed, and openings are temporarily boarded. That boarding is far easier to force than a locked door with a deadbolt. During active work hours it's fine. At 2am on a Saturday, it's a different story.

Valuable materials on-site

A typical extension build will have thousands of pounds of copper pipe, electrical cable, power tools, and building materials stored on-site — often in a skip, a temporary outbuilding, or simply stacked in what used to be your garden. Copper alone attracts dedicated thieves who know exactly what it's worth at the scrap merchant.

Tradespeople coming and going

Multiple different tradespeople visit your site. This makes it harder for neighbours to notice someone who shouldn't be there — and harder for you to know who's been on-site when you weren't present.

You might not be living there

If the works are significant enough that you've moved into rented accommodation or a family member's home, the property is unoccupied overnight. An empty house on an active renovation — with tools and materials inside — is a straightforward target.

The Internet Problem Nobody Mentions

Here's the issue that catches most homeowners completely off guard.

You decide, sensibly, to buy a couple of Wi-Fi security cameras before the build starts. You set them up, they connect to your home broadband, and footage uploads to the cloud. Job done — or so you think.

Then the builders start. Within days, one of the following happens:

• The router gets moved — to a different room, or just unplugged while they work on that wall
• The internet cable gets disturbed — chasing walls, digging outside, or accidentally cutting a line
• The power to that circuit goes off — while electricians reroute the consumer unit
• In a new build or major renovation — broadband simply isn't connected yet because you're waiting for Openreach

Your cameras go offline. The app on your phone shows them as disconnected. And they stay that way — sometimes for weeks.

This is exactly the window when you need them most.

The Fix: A SIM Router and a Cheap Data SIM

The solution is simple, inexpensive, and takes about 20 minutes to set up.

A SIM router (also called a 4G router or mobile broadband router) is a small device — roughly the size of a paperback book — that slots in a standard SIM card and broadcasts a Wi-Fi network using the mobile data network. It plugs into a mains socket. Your security cameras connect to it exactly as they would to your home broadband. Footage uploads to the cloud over mobile data.

You are not at the mercy of Openreach, your builder, or your home's power layout. As long as there is mobile signal at the property (and there almost certainly is), your cameras are online.

What does it cost?

A perfectly adequate 4G SIM router costs £25–£40. You can find them on Amazon — search for "4G SIM router" and look for brands like TP-Link, Huawei, or GL.iNet. You do not need a contract, a high-end model, or anything that requires technical knowledge to configure. Plug it in, insert the SIM, connect your cameras.

For the SIM itself, you want a pay-as-you-go data SIM with a monthly data bolt-on. Security cameras use relatively modest amounts of data — typically 1–5 GB per month per camera, depending on resolution and how much motion they detect. For 2–3 cameras, a 10–20 GB monthly plan is more than enough.

Which SIM should you use?

Any UK network works. For cost, these are the best options:

• Smarty — 12 GB for around £6/month, runs on Three's network (excellent coverage)
• Three — Various data-only SIM plans, often with unlimited options
• Lebara — Competitive pricing, good for short-term use
• GiffGaff — Easy to manage, runs on O2

You can cancel after the build finishes. No long-term commitment required.

Camera Placement During a Renovation

Think about coverage differently during a build than you would for a finished home:

• Rear of the property — where the extension is being built and access is easiest. This is your most important angle.
• Materials storage area — anywhere tools, copper pipe, or expensive materials are left overnight
• Scaffold access points — the foot of the scaffold where someone would climb
• Front of the property — especially if you're not living there. A camera visible from the street is also a deterrent.

Cameras do not need to be permanently installed. During a build, battery-powered cameras (like Eufy or Arlo) are often easier — no cable to run, positioned wherever makes sense, repositioned as the build progresses.

Other Practical Steps

Cameras and connectivity are the foundation, but a few other measures make a meaningful difference:

Site security signage

A sign that reads "CCTV in operation — 24 hour recording" visibly deters opportunists. They will move on to an easier target. Signs cost a few pounds and take two minutes to put up.

Secure the scaffold

Ask your scaffolding company to fit a scaffold alarm or anti-climb measures. Some companies offer this as standard; others will do it if asked. At minimum, ensure the lowest scaffold tube is high enough that it can't be reached from the ground without a ladder. Lock scaffold gates overnight.

Temporary lighting

A simple motion-activated floodlight positioned to cover the rear of the property and the scaffold access is cheap (under £20) and highly effective. Nobody wants to be suddenly lit up at 2am.

Talk to your neighbours

This is underrated. Tell the neighbours on both sides that you have a build happening and ask them to call you (or the police) if they see anyone on the site out of hours. Give them a contact number. Neighbours who are actively watching out are more valuable than any piece of technology.

Don't leave power tools on-site overnight

Talk to your builder about this explicitly. Power tools — drills, circular saws, multi-tools — are a primary target. A professional builder should be taking their tools home or locking them in a van. If tools are left on-site overnight in an unsecured space, they will eventually be stolen. This causes delays and costs money that will likely come out of your contingency.

Improve temporary boarding

Temporary boarding on openings is often just a sheet of OSB fixed with a few screws. Ask your builder to add a hasp and padlock, or a proper temporary door. The additional cost is minimal.

Sort Your Insurance Before Work Starts

This belongs in the planning phase, before a single tool arrives on-site:

• Notify your home insurer — Most policies require you to inform them of major building works. Failure to do so can invalidate the policy.
• Check for unoccupancy clauses — If you move out during the works, your standard policy may not cover the property after 30–60 days unoccupied.
• Consider site insurance — Your builder should have their own public liability insurance, but site insurance (covering materials and the structure during the build) is worth considering for larger projects.
• Document everything — Keep receipts and photographs of all materials delivered to site. If there is a theft claim, you will need to prove what was there.

The 30-Minute Setup That Covers You for the Whole Build

If you do nothing else from this guide, do this before your build starts:

1. Buy a 4G SIM router — £25–£40 on Amazon. TP-Link M7350 or similar.
2. Get a data SIM — Smarty or Three. Activate a 10–20 GB/month plan (£6–£10/month).
3. Set up 2–3 cameras — Position to cover the rear, scaffold access, and materials storage. Battery-powered cameras are simplest during active works.
4. Connect cameras to the SIM router — They connect exactly as they would to normal Wi-Fi.
5. Put up signage — "CCTV in operation" signs, visible from the street and rear access.
6. Add a motion-activated floodlight — Covering the rear/scaffold area.
7. Call your insurer — Notify them works are starting.

Total time: 30 minutes. Total cost: under £100. Peace of mind: considerable.

What Happens If Something Does Get Stolen

If despite your precautions a theft does occur:

• Report to police immediately — Get a crime reference number. You will need this for any insurance claim.
• Download camera footage — Pull the relevant footage from the cloud app immediately. Cloud storage is often limited to the last 7–30 days.
• Document what was taken — Photograph the area and make a detailed list. Cross-reference with delivery notes and material receipts if you have them.
• Notify your builder — If their tools or materials were taken, they need to know immediately. Work out who is responsible for the claim between you.
• Contact your insurer — Within 24 hours if possible.

This is another reason to keep a proper daily site diary and document materials as they arrive. If you can show exactly what was on-site on a given day, you are in a much stronger position with an insurer.

Keep a Daily Site Diary

Ted lets you log daily progress, photograph materials as they arrive, and keep a timestamped record of your build. If something goes wrong — theft, damage, a dispute with your builder — you have a complete, dated record of everything that happened.

Track Your Build for Free

Keep a complete record of every payment, task, and conversation with your builder. Ted is free to download on iOS and Android.