Open Windows Burglary Risk | Keep Air, Lose the Gap
Chichester Police warned of daytime break-ins through open windows in July 2026. Crawley faces the same risk. Here's what to fit and why it works.
On 7 July 2026, two homes in Eastergate and Westergate were burgled in broad daylight. Cash and jewellery taken. No forced entry. The windows were simply open, and someone walked the street until they found one low enough to climb through. Chichester Police put out a public warning two days later, reported by the Sussex Express on 9 July. The language was measured. The implication wasn't: if you leave a ground-floor or accessible first-floor window open while you're out, you're not relying on security. You're relying on luck.
I'll say it plainly. Ventilation and security are not in conflict. The idea that you have to choose between a comfortable house and a secure one is a myth the hardware aisle at B&Q has done nothing to correct. The right fittings let air through and keep people out, and a locksmith can fit them in under an hour. Most people don't know these products exist until after something goes wrong.
Why July and August Produce a Predictable Pattern
It's not complicated. Hot weather means open windows. Open windows mean access points that wouldn't otherwise exist. Burglars who work daytime hours, and a significant proportion do, because that's when houses are empty, walk the street and look for what's available. They're not drilling locks or snapping cylinders on these jobs. They're stepping through a gap you left for them.
Sussex Police's own seasonal data, and national figures from the Office for National Statistics, consistently show that opportunist residential burglaries tick upward in summer. The Eastergate and Westergate incidents on 7 July are a specific, recent, local example of a pattern that plays out every year across the county. Crawley is not insulated from it. Three Bridges, Broadfield, Ifield, Bewbush, Gossops Green: terrace housing, semi-detached 1970s and 1980s stock, bay windows at waist height, kitchen windows left on the latch while someone pops out for two hours. The exposure is exactly the same.
And here's the part that catches people out as summer wears into late August and September. Temperatures in West Sussex can stay stuffy well into autumn. Warm spells in late September are not unusual. The habit of leaving windows open doesn't stop the moment schools go back. Neither does the risk.
What 'Through an Open Window' Actually Means
People sometimes picture a small fanlight at ceiling height and wonder how that's possible. The reality is usually a casement window opened to the first or second notch on a standard stay, positioned anywhere between ankle height and shoulder height on a ground floor. A 200mm gap on a side-return window, a kitchen window over a flat-roof extension, a bedroom window on a return that backs onto a footpath: these are the access points. Not skylights. Not upstairs windows on a sheer brick wall.
The method in Eastergate and Westergate was almost certainly a reach-and-grab or a full entry through the opening. The time window, 10am to 4pm, is the working day. The owners were out. That's all the preparation required.
The Three Things You Can Fit to Solve This
None of these are complicated. None cost more than £50 in parts. A locksmith fits all three routinely, and the combined job on a standard semi takes 45 minutes to an hour.
Window Restrictors
A restrictor limits how far a casement or top-hung window can open. Most fit to the frame and the opening sash with a steel cable or a rigid arm, and they hold the window at a set distance, typically 100mm, which is enough ventilation and nowhere near enough for entry. Better ones are key-operated, so you can release the full travel when you want to. Prices for decent key-lockable restrictors start around £15 to £25 per window for parts.
These are the primary tool for ground-floor casement windows on housing in RH10, RH11 and across to RH12. Fitted correctly into the frame and not just screwed into uPVC sash with short self-tappers, they're genuinely effective.
One caveat: if the window opens onto a fire-escape route, you need the key-release type, and the key needs to be accessible. Building regulations and your insurer will have views on this.
Sash Stops (for Sash Windows)
Sash stops are small bolts that fit into the inner sash's staff bead channel and drop into a hole drilled at a chosen height. They're used on traditional timber sash windows, which you'll find on older properties in the Northgate and parts of central Crawley, and in villages like Horley and East Grinstead. Set the hole at 100mm from the closed position and the window opens exactly that far and no further. A burglar can't push it further up without removing the stop, which makes noise and takes time, neither of which they want.
Cheap, discreet, effective. A pair of sash stops from a reputable hardware supplier costs under £10. The fitting is five minutes if you know what you're doing.
Key-Lockable Window Handles
The standard espag handle on a uPVC casement can usually be replaced with a key-lockable version in the same footprint. You keep the normal operation, except the handle won't move without the key. This is particularly useful on windows adjacent to doors, or on windows where the opening restrictor isn't practical due to the design. Brands like Mila, Maco and Winkhaus all make key-lockable espag handles that fit the common 7mm and 9mm spindle sizes.
Replacing a handle yourself is possible if you're confident with a screwdriver and know your spindle size. Getting it wrong means a handle that doesn't close properly, which is the opposite of what you want. For a locksmith, swapping a handle is a 15-minute job.
A Quick Guide to Which Fix for Which Window
| Window type | Best fix | Approximate parts cost | Notes |
|---|---|---|---|
| uPVC casement, ground floor | Key-lockable restrictor | £15 to £30 | Fix into frame, not just sash |
| uPVC casement, first floor accessible | Restrictor or key handle | £15 to £25 | Flat roofs, extensions |
| Timber sash | Sash stops | £8 to £15 | Pair per window |
| uPVC tilt-turn | Key-lockable handle | £20 to £35 | Check spindle size first |
| Top-hung fanlight | Restrictor with cable | £12 to £20 | Often overlooked |
Labour for a locksmith fitting two or three of these on the same visit: expect £60 to £90 for the callout and work, plus parts, depending on how many windows and what they find on the day.
The Insurance Angle
Most home insurance policies contain language about reasonable precautions. The exact wording varies, but the principle is consistent: if you left a window open and someone got in, the insurer can decline or reduce the claim on the basis that you didn't take reasonable steps to secure the property. 'It was hot' is not an answer they're obliged to accept.
A policy from a mainstream insurer covering a property in RH10 or RH11 will typically require ground-floor windows to be locked when the property is unoccupied. 'Locked' means physically secured, not just closed. A window on its standard stay latch, open to the second notch, is not locked. It is not even close to locked.
Fitting key-lockable restrictors doesn't just reduce the risk of break-in. It means that if something does happen, you have a better story for the insurer and, in most cases, actual evidence the window couldn't be pushed wider.
What This Isn't About
This isn't a pitch for a complete security overhaul. The people burgled in Eastergate and Westergate almost certainly had decent front doors. They may well have had decent cylinders. None of that mattered because the point of entry wasn't the front door.
Window security gets discussed less than door security in the locksmith trade, partly because there's less margin in it. A window restrictor at £20 doesn't generate the same conversation as a Ultion cylinder at £80. That's a commercial reality. But if a ground-floor window is the weakest point on a property, fitting an anti-snap cylinder on the front door is a reasonable thing that doesn't fix the problem.
Look at the whole envelope. Doors, yes. Windows too.
The Practical Check to Do Today
Walk the ground floor. Note every window that opens. For each one, ask: if I left this open on the first notch and went out for three hours, could someone reach in and release the handle, or push it wide enough to enter? If yes, that's a window that needs a restrictor or a key-lockable handle.
Do the same for any first-floor window accessible from a flat roof, a garage roof, a side-return or a fence line. These come up regularly on the estates in Maidenbower, Pound Hill and Tilgate where rear extensions and garages create step-up access that wasn't there on the original build.
The job isn't big. It's just one that most people put off until something happens nearby, and then do in a hurry. The Chichester warning is 'something happening nearby'. Take the prompt.
If you'd rather have someone check the windows properly and fit the right hardware in one visit, Rapid Response covers Crawley and the surrounding RH postcodes, and we're usually on site in under 30 minutes. Call ahead, tell us what you've got, and we'll give you an honest price before we come out.
Source: Summer burglary warning issued after thieves enter two West Sussex homes through open windows
Katie Lambert, Security and standards specialist
Katie is the one who reads the test reports, and handles the survey work, the insurance questions and anything where the British Standard actually matters. Will happily explain why the number on the box is not the number that counts.
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