Glass is a compromise you have already made. It is the reason the house is pleasant to live in and it is the easiest way into it, and no amount of hardware entirely resolves that.
What is available is delay and discouragement. Almost all opportunistic entry is quick, quiet and looking for an easy option, and most of the useful work here is about not being the easy option rather than about being impregnable.
What glass actually does
Most domestic double glazing is toughened, not laminated, and toughened glass is a safety product rather than a security one. It is designed to fail safely, which means when it fails it produces a completely clear opening in one go.
Laminated glass is the meaningful upgrade. It holds together on a plastic interlayer, so getting through it means cutting it or striking it many times, both of which take time and make a great deal of noise. That is the entire mechanism of glazing security and it is worth understanding before spending on anything else.
Applied security film is a cheaper approximation. A good thick film properly applied to a clean pane, ideally bonded into the frame rather than stopping at the glass edge, gives some of the benefit. A thin film applied over the visible glass only will peel out of the frame with the pane.
The free half of this page
Do this before buying anything, because it is worth more than most of what you could buy.
Walk outside after dark, with the lights on inside, and look in. From the pavement, from the side passage, from the back fence. Whatever you can see is what is being advertised.
- Car keys visible from a window or reachable through the letterbox is the single most common one, and stealing a car by fishing the keys through the door is a well-established method. Keys go somewhere out of sight and away from the door.
- Laptops, tablets, phones, cameras and tools left where they can be seen from outside.
- Packaging for anything expensive, left by the bin, is a note saying what is now inside.
- A ladder, wheelie bin, garden furniture or water butt left against the house is a way onto the flat roof and the first floor. Chain the ladder, move the bins.
Fix the sight lines. A high fence and dense planting at the front feel private and mostly provide cover for somebody working on a window. Low at the front, high at the back is the usual advice and it is sound. Fix the lighting: a light that comes on and stays on for a while beats a floodlight that dazzles, and a dark side passage is the most useful thing you can give an intruder.
Locks and stays
- Key-operated window locks on every ground floor opening light, and on anything on the first floor reachable from a flat roof, a porch or a bin store.
- Locking stays on casement windows, so the window can be left ajar for ventilation without being openable from outside. Genuinely useful in summer.
- Sash stops on sliding sashes, which allow a small ventilation gap and prevent the sash being raised further.
- Check the beading on uPVC windows. Externally beaded units, common on older installations, can have the beads removed and the sealed unit lifted out entirely without breaking anything. Security clips or a change to internal beading fixes it. If you can see the beading from outside, this applies to you.
- A window that has been painted shut is secure and is not an escape window. Know which of yours are which.
Upgrading the glass
You are unlikely to relaminate the whole house, and you do not need to.
Pick the two or three panes that matter:
- The one beside the front door, within reach of the latch or the thumbturn.
- The most concealed ground floor window, at the side or the back, out of sight of neighbours and the street.
- Any pane in a door itself.
Replacing the sealed unit in an existing frame with a laminated one is a modest job and much cheaper than a new window. It addresses the reach-through problem and it removes the quickest, quietest option.
Glazing beside a door is the priority because it converts a strong door into a formality. See reinforcing a door and its frame: a door with a good lock, long screws and a London bar, next to a pane you can put an elbow through and reach the handle, has not been secured.
Bars grilles and shutters
These work. They are also the point at which the house starts to feel like somewhere under siege, and they carry a real safety cost.
- Internal removable grilles are better than fixed external bars: less visible, less depressing, and removable.
- Shutters, internal or external, are the traditional answer and are effective, quiet and reversible.
- Fixed bars on a bedroom window are dangerous and in many cases unlawful, because they remove the escape route.
- Consider what the appearance says. A house that is visibly fortified in a street of houses that are not tells everyone that there is something in it worth fortifying against.
For most households the honest ranking is: nothing on view, then lighting and sight lines, then locks, then laminated glass, and bars a distant fifth reserved for a specific opening with a specific problem.
Escape comes first
Smoke alarms outrank everything on this page. One on every floor, tested monthly, and a plan everybody has actually walked through. See siting and testing alarms.
The places people forget
- The back and the side. Attention concentrates on the front, and entry concentrates on the quiet side.
- The downstairs loo window, small, obscured, often left on the latch, and frequently the only one without a lock.
- The kitchen window above the sink, left open for steam and forgotten.
- Patio and French doors, which are mostly glass and often have weak multipoint keeps.
- Conservatory doors, usually the weakest external door in the building, and connecting straight into the house.
- An integral garage, secured by an up-and-over door, with a hollow-core internal door into the house behind it.
- Flat roofs, porches, bin stores and outbuildings, all of which are a way to reach a first floor window nobody locks.
- The window somebody props open for a cat.