How to Burglar-Proof Doors and Windows Cheaply

You do not need a big budget to make your home harder to break into. A lot of burglaries involve ordinary doors and windows that are unlocked, poorly fitted or have weak hardware. With a few hours, some basic tools and modest spending, you can burglar-proof doors and windows in ways that genuinely raise the effort required to get in. This guide goes through the weak points one at a time, starting with free fixes and working up to low-cost upgrades.

A quick note: prices change and products vary, so we do not quote costs. Check labels for recognised security standards, and if you rent, ask your landlord before making changes. Where your insurer sets requirements for locks, follow them. [VERIFY: your policy]

Step 1: Do the free things first

Before buying anything:

• Lock up every time, even when you are at home or in the garden.
• Take keys out of the lock and keep them out of sight and away from the letterbox.
• Close and latch windows, especially at the back and on upper floors that can be reached from a flat roof, porch or garage.
• Remove climbing aids, such as bins, ladders and garden furniture, from beneath windows.
• Trim hedges that hide the front door or windows from the street.

These cost nothing and fix the commonest weaknesses.

Step 2: Check what you already have

Walk around and test each door and window:

Item	What to check
Door frame	Is the wood solid or rotten, are there gaps around the door?
Hinges	Are screws tight, do they sit on the inside of the door?
Lock	Is it a quality lock that locks properly, or a simple latch?
Glass panels	Are there panels near the lock that a thief could break and reach through?
Windows	Do the locks work, is there a key available to you, are frames sound?

Rattle and push gently. If something moves a lot, it is a weak point.

Step 3: Strengthen external doors

Front and back doors

A door is only as strong as its weakest part. The cheapest, most effective upgrades include:

• Fit a better lock. On a wooden door, a five-lever mortice deadlock to BS 3621 is a commonly recommended standard, and many insurers specify it. Fitting one involves cutting a slot in the door; if you are not confident, ask a locksmith. For uPVC and composite doors, check whether the multi-point lock is of good quality. If it was fitted a long time ago, it may be vulnerable to “snapping” and could be worth replacing with a lock tested to resist this. Look for recognised approvals. [VERIFY: current standards]
• Add a door chain or door limiter so you can see who is outside before opening fully. Use a spy hole or video doorbell for the same reason.
• Reinforce the frame. A metal strike plate or reinforcement kit around the lock can stop the frame splitting if kicked. Fix with long screws that reach the solid wood behind the frame.
• Install hinge bolts on outward-opening doors and on any door where hinges are exposed, so the door cannot be lifted off even if hinges are removed.
• Fit a letterbox cage or restrictor to prevent tools or hands being used to reach in.
• Use a door security bar if you want extra protection while at home or away, noting that you must be able to open quickly in an emergency such as fire.

Back and side doors

These are often the most vulnerable because they are out of sight. Consider adding bolts top and bottom for use when at home, and always lock with a key when out. Keep side gates locked, with a lock on the inside if possible.

Garage doors

The internal door between a garage and your house should be as secure as an external door. Up-and-over garage doors can sometimes be forced; adding a floor-mounted lock or extra bolts might help.

Step 4: Strengthen windows

Window locks

Fit key-operated locks on all accessible windows, including side and rear. Many modern double-glazed windows come with locks, but people often do not use them or lose the keys. Make sure keys are kept somewhere safe but accessible to you in case of a fire, and not left on the window sill.

For older sash windows, sash stops or screw-in bolts can restrict opening while still allowing ventilation. Fit a lockable stay on casement windows you would like to leave ajar.

Glass

Laminated glass is harder to break and is more expensive than standard glass. If you cannot afford a full upgrade, consider applying security film to the most vulnerable panes (ground-floor windows, glazed doors). It will not make glass unbreakable, but it can slow entry and reduce shattering. Check the product’s claims before buying.

Louvre windows and skylights

Louvre windows are often easy to remove, so replace them or fit additional security. Skylights and roof lights that can be reached should have locks or bars.

Step 5: Patio and sliding doors

Patio doors can be a weak point. Basic fixes:

• Fit anti-lift devices that stop the door being raised off its track.
• Add extra locks at the top and bottom of the frame.
• Place a wooden or metal bar in the track when you are at home or out.
• Consider a lock tested to recognised standards if replacing.

Because glass is a large part of the door, ensure it is either laminated or protected by film, if possible.

Step 6: Improve visibility and deterrence

Hardware is only half the picture. Burglars generally want to avoid being seen.

• Install a dusk-to-dawn light at the front door and a motion-activated light at the back.
• Put up visible deterrents such as an alarm box or camera sign, but only if you actually have the equipment. Fake signs may have some effect, but they should not replace real measures.
• Keep front gardens open enough for passers-by to see doors and windows.
• Use timers on lights when away in the evening.

A budget-friendly priority list

1. Use your existing locks every time.
2. Reinforce the weakest door (often the back door).
3. Fit window locks on accessible windows.
4. Add hinge bolts and a letterbox cage.
5. Add security film or upgrade glass on vulnerable panes.
6. Improve lighting and trim vegetation.
7. Consider replacing a poor-quality door only if the other steps are not enough.

Rentals and leasehold

If you rent, you may not be permitted to change locks, but you can ask your landlord or letting agent to fix poor security. Landlords have legal responsibilities regarding the safety of their properties, and security upgrades may be appropriate. Portable devices like door wedge alarms or portable door locks may help temporarily, but check they do not breach your tenancy or fire safety rules. For leasehold flats, check with the managing agent before changing external doors, which may be the freeholder’s responsibility. [VERIFY: tenancy terms]

When to call a professional

Call a locksmith or glazier if you:

• Are replacing mortice locks or multi-point mechanisms.
• Suspect frame damage or rot.
• Have lost keys or inherited a property with unknown key holders.
• Need work to meet insurer requirements.

Choose a reputable local tradesperson with verifiable reviews or accreditation. Beware of cold callers offering “free security checks”.

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FAQs

What is the cheapest upgrade that makes a real difference?
Using the locks you already have and fitting window locks and hinge bolts. These are inexpensive and tackle common weaknesses.

Are uPVC doors secure?
Many are, but older ones can have weak locks. Check that the multi-point lock is of good quality and consider replacing a lock vulnerable to snapping.

Will security film stop a burglar?
It makes glass harder to break through quickly and can reduce the amount of noise-free entry, but it is not a guarantee. Use it alongside good locks and lighting.

Do I need to tell my insurer about changes?
It is worth checking your policy. Better security might reduce risk, and some policies require specific locks. Contact your insurer if unsure.

Conclusion

Burglar-proofing doors and windows works best as a sequence: lock up consistently, fix the weakest points, add low-cost hardware and keep your property visible. You might not need to spend much to make a meaningful difference. If in doubt, ask your local police crime prevention team or a reputable locksmith for advice tailored to your home.