Ground-floor windows are the entry a locked door redirects people to
Securing a door reliably shifts the attempt to the windows beside it, starting with the ground floor. The products differ mostly by what frame they can be fixed to: timber takes a screwed lock anywhere, vinyl has a reinforcement that must be found, and thermally broken aluminum often should not be drilled at all. This hub covers bolts screwed to hinged windows, keyed or push-button, on the handle side or on the hinge side, the one almost nobody reinforces; clamp locks that grip the track of a sliding window, some of which hold it in a ventilated position; and a telescopic bar that clamps in the reveal without drilling. We compare frame compatibility, keyed and keyless operation, fitting side and fitting method.
Bolt lock, inward-opening windows · 4-pin cylinder · keyed alike · ABUS level 5 · key to open only
A bolt-action window lock for inward-opening windows and French windows. ABUS states a four-pin cylinder, keyed-alike operation, and a mechanism that locks by pushing — the key is needed only to open it.
Best for: Ground-floor windows that get locked every night, where hunting for a key each time would end the habit.
≈ $60
A named hardware reference — U 9819 — from a US window-hardware house, with a line drawing published for the rail dimension · thumb turn screw, keyless, no tools · rails up to 1/8 in · natural aluminum · secures the window closed OR in a ventilated position · four locks for five dollars forty · no permanent modification
The cheapest way onto this shelf, from the only maker here that publishes a line drawing to check the fit against.
Best for: Four sliding windows, checked against the drawing first, with nothing permanent done to the frame
≈ $5
Hinge-side lock · bolt rated to one metric ton of pressure · ABUS level 10 · 123 × 42 × 86 mm (4.84 × 1.65 × 3.39 in)
A hinge-side security bolt for inward-opening windows — the side almost nobody reinforces. ABUS states the bolt protects up to one metric ton of pressure and rates it at security level 10 on its own scale.
Best for: The half of the window that every other lock in this hub ignores.
≈ $68
Three window locks · push-button locking, no key · M5×50 self-tapping screws supplied · white
Three window security bolts operated by push button rather than by key, which BASI states lock by hand and release quickly. Each comes with four M5 × 50 mm (0.20 × 1.97 in) self-tapping screws.
Best for: Doing every ground-floor window at once, without a key for each.
Zinc die-cast body · lockable · fits top, bottom or handle side · 2 keys · retrofit
A lockable window security bolt in a zinc die-cast housing, which BURG-WÄCHTER states can be fitted on the top, bottom or handle side of a window or balcony door with a few holes.
Best for: A window where the best fixing point is not the handle side — a tall casement, or a balcony door.
≈ $69
TIGHTENED WITH A KEY, not a thumbscrew — the only lock here that cannot be loosened by hand · rails up to 1/8 in (3.2 mm) · rust-resistant aluminum alloy · about 83 cents a lock, by far the cheapest here · offered in aluminum, black or white and in 8, 10, 12, 15 and 30 packs · the reference reads DD04-10 on a 12-pack
The only window lock on this shelf that needs a tool to release — which is both its security and the fire risk the hub warns about.
Best for: A ground-floor window or a child's room, where nobody inside should be able to loosen it by hand
≈ $10
Telescopic security bar · 101–175 cm (39.8 to 68.9 in) · orange, visible from outside · rubberized pads · no drilling
A telescopic bar clamped into the window reveal rather than screwed to the frame — vertically, horizontally or diagonally. SCHMIDT states 101 to 175 cm (39.8 to 68.9 in) of adjustment, rubberized pressure pads, and a deliberately visible orange finish.
Best for: A rented apartment, a vacation rental, or any window where nothing may be drilled.
TWO track widths from one lock: up to 3/16 in with the detachable rubber insert, or 3/8 in without it · a vinyl lining that stops the frame being scratched and adds grip · heavy-duty aluminum · no-drill thumb screw · for horizontal AND vertical sliding windows, patio doors and window air conditioners · 10 locks
The only window lock here that fits two track widths, and the only one with a lining between the metal and your frame.
Best for: A house with sliding windows of more than one track width, or a window air conditioner that must stay put
≈ $16
Five window locks · push-button, no key · M5×50 screws supplied · white
The five-unit box of BASI's keyless window bolt, for a house with more accessible windows than a three-pack covers. Same push-button mechanism and same 50 mm (1.97 in) screws.
Best for: A house with five or more reachable windows — usually a front, a back and a side.
A home has more windows than you think. A multipack covers them all for a low unit cost.
A window accessible at ground level is often the simplest way in. A lock there changes the cost-to-effort ratio of an attempt.
PRIME-LINE U 9819 sliding window security lock, 1/8 in rail, 4-pack
Drilling a thermally broken aluminum profile can void the window's warranty, and in a rental you drill nothing. A sliding-window clamp lock grips the track and a telescopic bar clamps in the reveal: neither needs a hole.
Yes, if it is the only escape route from the room, especially upstairs in a fire. The key has to stay immediately to hand and known to all the occupants; BASI's push-button locks release by hand, with no key.
Yes, if the screws bite the steel reinforcement in the profile and not just the PVC, which holds little on its own: find the reinforcement before drilling. ABUS states its FTS3003 and FAS101 hold on PVC only with the matching fixing kit; BASI supplies M5 × 50 mm screws, long enough to reach it.
A window reachable from a roof, a balcony or a downpipe is as exposed as a ground-floor one. Accessibility comes before height.
No: it prevents opening, not breaking. Security film and laminated glazing answer that other question.
Yes. On a sliding window, a clamp lock tightens on the track with a thumbscrew or, on the NUK3Y, a key. On a hinged window, a telescopic bar like the SCHMIDT 123837, adjustable from 39.8 to 68.9 in, clamps in the reveal. Both hold by pressure, so less than a screwed bolt.
A window left ajar in the daytime on a ground floor is a simple way in. On a sliding window, a clamp lock set on the track holds it partly open; the hinged-window bolts in this hub only hold a closed sash.
They stop the handle being turned from outside through a hole in the glass or a hole drilled in the frame. Against levering the sash, the commonest method on a window, they are not enough alone: it takes a lock on the frame. This hub does not cover them.
A window is sometimes the only escape route: the key stays to hand and known to everyone. A lock prevents opening, not breaking — and since windows are mostly levered open, a lock on the frame counts for more than a keyed handle alone.
There is no table here, and the reason is in the listings. The figure published most often across these 9 products is operation, given by 7 of them — short of the four in five a column needs to compare rather than to display gaps. Each product page says what its own maker published.
$5 – $10
2 models
PRIME-LINE U 9819 sliding window security lock, 1/8 in rail, 4-pack, NUK3Y PRODUCTS K3 DD04-10 sliding window security locks, aluminum, 12-pack
$16 – $60
2 models
Shop Square LLTR10 adjustable aluminum window stoppers, 10-pack, ABUS FTS3003
Specifications: manufacturer sheets for home security products and the matching Amazon product pages. Prices and availability: Keepa.
Most recent revision in this category: October 8, 2026.
Prices quoted in these summaries are dated readings. The live price is shown next to each product.
