Security Grilles
A grille has to keep people out without ever trapping anyone in
Everything else we fit is a lock. A grille is a barrier, and that changes the first question completely. A lock only ever has to resist someone on the outside. A grille sits across an opening that people may one day need to get through in a hurry, in the dark, possibly in smoke, and quite possibly not the person who owns the key. Get that wrong and you have made a property less safe rather than more, however strong the steel is.
So the conversation always starts with the opening rather than the product. Is this a window nobody climbs through, or a window that is somebody's only way out of a basement flat? Is it a shopfront that locks up empty at night, or a unit with a flat above it? Those answers decide whether a grille is fixed or retractable, whether it is locked with a key or released from inside without one, and in some cases whether it should go on that opening at all.
The rest is straightforward and, honestly, unglamorous. Steel, sizes, fixings into sound masonry rather than render, and a mechanism that will still run in five winters. Most of the grille work we are called out to repair failed for dull reasons: fixings into crumbling brick, tracks never cleaned, or a lock at the bottom of a shutter that has taken road grit every day since it went in.
How a Grille Installation Actually Runs
Before the steel, the sizes or the price, we need to know what the opening is for. A window somebody might one day climb out of is a different job to a window nobody ever touches.
Retractable Grilles That Fold Away
Concertina grilles run on a top track and fold back into a stack against the reveal, so the opening is clear during the day and barred at night. They suit shopfronts, basement flats and ground-floor windows where a permanent cage would be unbearable to live behind. The things that matter are the track being dead level, the stack having somewhere sensible to sit, and the whole run being fixed into structural masonry rather than into render or a timber lining.
Fitting Locks and HardwareEscape Routes Come First
Any grille across a window or door that forms part of an escape route needs to open from the inside without a key, using a thumbturn or a quick-release catch. This matters most in basement and lower-ground flats, where the barred window is often the only alternative to the front door. We will ask about escape routes before quoting, and where a room's only exit is involved we will tell you to confirm the arrangement with your local building control or fire officer rather than take our word for it.
After a Break-InFixed Bars, Window Grilles and Basements
Where an opening is never used for access or escape — a light well, a store, a rear window behind a boiler — a fixed grille is simpler, cheaper and stronger than anything that moves. The security is entirely in the fixings: bolts into solid brick or concrete, resin anchors where the substrate is doubtful, and heads that cannot be attacked from outside. A beautifully made grille screwed into soft mortar is decorative rather than protective.
Upgrade the Locks TooWhy Escape Comes Before Security
- Escape routes established before anything is quoted — internal release where people need to get out, and we will say when an opening should not be barred at all.
- Fixed into structure, not into render — the fixings are the security. Resin anchors where the brick is doubtful, and heads that cannot be attacked from outside.
- Consent flagged before we start — conservation areas, listed buildings and leaseholds all affect what can go on a front elevation, and it is better to know first.
- 180-day warranty on locks, lifetime on keys — on the grille locks we supply and fit, with the parts named on the invoice.
Our Process - What Happens When You Call
- Tell us what the opening is. Shopfront, basement window, light well, rear door or communal entrance. What it is used for shapes the answer more than its size does.
- Say whether anyone could need to get out through it. Bedrooms, basements and any room where the window is the second way out change the specification immediately.
- Measured on site, not from a photograph. Grilles are made to the opening. We measure the reveal, check the substrate for the fixings and agree where a folding stack will sit.
- Fitted, tested and shown to you. Locked and unlocked from both sides in front of you, including any internal release, so everyone in the building knows how it works.
Why Choose N1 Locksmiths?
You speak to the person doing the job
The engineer who surveys the opening is the one who fits the grille, so nothing is lost between the measurement and the installation.
Priced after a survey, not over the phone
Grilles are made to size. We will give you the basis of the cost on the call and a firm figure once the opening has been measured.
Fire safety raised by us, not by you
We ask about escape routes as a matter of course, and point you to building control where a room's only exit is involved.
180-day warranty on locks, lifetime on keys
Grille locks and any keys we cut are guaranteed, with the products named on the invoice for your insurer.
Existing grilles repaired, not just replaced
Seized shutter locks, worn tracks and failed catches are usually fixable, and we quote that before quoting a new installation.
15–30 minutes across N and NW
Worked from Holloway Road, so a shutter lock that has seized before opening time is not a lost trading day.

Start with the opening, not the product
Tell us what the opening is, roughly how wide it is, and whether anybody could ever need to get out through it. Those three answers decide almost everything: retractable or fixed, internal or external, key-locked or quick-release. From them we can give you the basis of a cost on the phone and book a survey to measure properly, because grilles are made to size and nothing useful comes from guessing. Surveys across the N and NW postcodes are usually within a day or two, and an engineer can reach you within 15–30 minutes for a seized shutter lock or an existing grille that has failed.
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Physical barriers work best alongside the rest of the security on a building. These are the services most often specified with grilles — cameras covering the openings that are now barred, door entry on a communal entrance, and the locks on the doors themselves brought up to the same standard.
Areas We Cover Across London
We survey and fit security grilles across N1 to N22 and NW1 to NW11 from 37 Holloway Road in N7, and the work divides neatly between shops and basements. The high streets through Camden Town, Kentish Town, Holloway, Caledonian Road and Angel are almost all retractable shopfront grilles, where the constraints are planning consent and keeping the window visible at night rather than the steel itself. The other half is residential and mostly below street level — the lower-ground flats and light wells that run through the Victorian terraces of Barnsbury, Highbury, Canonbury and Islington, where a sunken area gives cover to work unseen and where escape routes matter more than anywhere else we fit.
FAQs – Security Grilles
Do I need permission to fit a security grille?
Often, and it is worth checking before you order anything. Conservation areas and listed buildings restrict what can be added to a front elevation, external shutters on shopfronts frequently need planning consent, and if you are a leaseholder your lease may require the freeholder's agreement. Internal grilles are generally far less contentious than external ones, which is one reason we suggest them first.
Will a grille make my flat feel like a prison?
It is the commonest worry and a fair one. Retractable grilles fold back into a stack against the reveal so the window is clear all day, which is quite different to living behind fixed bars. Powder coating in a colour that matches the frame helps enormously. For most homes we would fit retractable and only use fixed bars where an opening genuinely is never used.
Can a grille be opened from inside in a fire?
It must be, wherever the opening forms part of an escape route, and that means a thumbturn or quick-release catch rather than a key. This is most critical in basement and lower-ground flats. We specify internal release as standard on habitable rooms, and where a window is a room's only alternative exit we will ask you to confirm the arrangement with building control or your fire officer, because we are locksmiths rather than fire safety assessors.
What is the difference between a grille and a roller shutter?
A grille is an open barrier you can see through, which keeps a shopfront visible at night and lets light into a flat. A shutter is a solid or perforated curtain that closes the opening completely, giving more privacy and weather protection but a blank frontage. Many high streets prefer or require open grilles for exactly that reason, so it is worth checking locally before choosing.
Will fitting grilles reduce my insurance premium?
It can, particularly on ground-floor and basement properties and on commercial units, but no insurer commits to that in advance and we cannot promise it. What we can do is give you an itemised invoice naming what was fitted and where, which is what an insurer asks for. Where a policy already specifies grilles as a condition, tell us the wording and we will fit to it.
My shop shutter lock has seized. Can you repair rather than replace it?
Usually. Shutter and grille locks sit at ground level taking road grit, rain and salt every day, so they seize far sooner than a door lock does. Cleaning, freeing and relubricating fixes a good proportion of them, and where the lock has genuinely gone the barrel or the whole lock can be changed without touching the shutter itself.
Can grilles be fitted inside rather than outside?
Yes, and internally is often the better answer. An internal grille avoids planning and conservation issues almost entirely, is protected from weather so it lasts longer and runs more smoothly, and cannot be attacked from the street. The trade-off is that it sits inside your window reveal, so it is more visible from within the room.
What about the communal door or the bin store in my block?
Those belong to the freeholder or the managing agent rather than to you, so they have to authorise the work. We are happy to survey, explain what would suit and put it in writing for you to pass on, which usually moves the conversation along faster than a resident describing it second-hand at an AGM.
Do you fit grilles to light wells and basement areas?
Regularly, and they are among the most worthwhile places to have them, because a light well gives someone cover to work in unseen. The two things that decide the job are the state of the brickwork for fixings and whether the basement has a window that must stay usable as an exit. Both are established on the survey.
How long does an installation take?
A survey takes half an hour or so. Fabrication to size means a gap of a week or two before fitting, depending on the specification. The installation itself is usually a half day for a single opening and a full day for a shopfront, with more where fixings need resin anchors into poor masonry.
How much do security grilles cost?
They are made to size, so an accurate figure needs the opening measured. We will give you the basis of the cost on the phone once we know the type of opening, roughly how wide it is and whether you want retractable or fixed, then confirm it in writing after the survey. Nothing is ordered until you have that figure.