Fit Window Stops Without Blocking Escape

Before you start

• Walk the house and write down which windows are in rooms people sleep in. Those are escape openings and they get different treatment from everything else.
• Open every window you plan to fit a stop to. A window that is painted shut or seized is already failing before anybody adds hardware, and that is the job to do first.
• Check the track material. Soft vinyl and thin aluminum mark under a clamping stop, which matters if the windows are not yours.
• If you rent, adhesive and clamp-on fittings usually come off cleanly, but ask before fitting anything that bears on a frame.

The job

1. Sort every window into one of two listsList one is escape openings: bedrooms, and any room somebody sleeps in even occasionally, including a converted den and a basement room with a bed in it. List two is everything else — bathrooms, utility rooms, kitchens with another exit, landings. Only list two is eligible for a keyed or permanent stop.
2. Choose the release type from the list, not from the priceOn list one, the stop has to release from inside with hands alone, immediately, by somebody who has never been shown how. On list two you can use a keyed stop, and the key lives somewhere sensible rather than in the lock. This is the only decision on this page that cannot be undone by unscrewing something.
3. Set the opening to a width that still ventilatesA stop set so tight that the room gets no air is a stop that gets removed in July and never goes back. Open the window to the narrowest position that still moves air through the room, and set the stop there. A window that stays limited all year beats one that spends the summer wide open.
4. Fit the stop where the sash actually stopsSlide the sash to the position you chose and mark the track at the trailing edge. Clamp the stop at the mark rather than forcing it into position with the window shut, which is how tracks get bent. Tighten until firm, then check the sash cannot push past it with a shove.
5. Test the release with the people who use that roomOn any window on list one, have the person who sleeps in that room open it fully from the limited position, without instruction. If they hesitate, the device is wrong for that window regardless of what the listing says. Children old enough to open their own window should be shown how, and told it is for getting out.
6. Check them again after a seasonClamps slide, screws loosen, and tracks collect grit. Push each sash against its stop once a season and confirm it still holds and still releases. A stop that has quietly slid is doing nothing at all, and you will not notice unless you check.

Stop and call somebody if

• The window is in a sleeping room and the only stop you have needs a key. Do not fit it there, buy the right kind instead.
• The window will not open at all. That is a joinery problem and it is more urgent than any security fitting.
• The room has fixed bars or a grille with no interior release and somebody sleeps in it. That needs a locksmith or glazier, and it is worth the call.
• A small child sleeps in the room and there is furniture under the window. Move the furniture before thinking about hardware.

What goes wrong

• Treating an insect screen as if it holds anything in or out. It does neither, and children lean on them.
• Fitting stops to every window in the house on a Saturday without sorting them into escape openings first.
• Setting the gap so narrow the room is stuffy, which guarantees the stop is removed and forgotten by the second warm week.

Where this applies

• Ground-Floor Windows — Habit: the overwhelming majority of ground-floor window entries are through a window that was left open or unlatched, not one that was forced.
• A Rented Apartment Door — The key list: in a rented apartment you have no idea how many keys were cut before you arrived, and no lock upgrade you can make changes that.
• The Back Door — Privacy: a back door is usually the only approach to the house where somebody can work unobserved for as long as they like.

Hardware this job may need

• Window Locks & Stops — limiting how far a window opens without trapping anyone

Sources

• U.S. Consumer Product Safety Commission — window safety and fall prevention
• National Fire Protection Association — home fire safety and escape planning
• International Code Council — model building codes and adoption