Sash windows can be secure when the fittings work and the sashes close properly. For example, we provide catches as part of every overhaul and draught proof. We also fit locking restrictors on request, and some insurers ask for them. We quote free after a visit.
Why old sash windows feel insecure
Firstly, a loose sash is easy to lift. Worn catches, shrunken timber and gaps at the meeting rail all make this worse. So the first step is often to make the window fit its frame properly.
That is why security and repair go together. A sash that rattles in its frame is rarely secure. Our guide to why sash windows rattle explains how gaps appear, because that shows how we close them.
Meanwhile, a painted-shut window may look secure but is a problem in an emergency. A good lock should let you open the window easily when you want to.
Catches
In short, the catch pulls the two sashes tight together at the meeting rail. A working catch stops the window rattling, and as a result it is harder to force. We provide new catches as part of our comprehensive overhaul and draught proof.
That service costs £188 per window. However, the price covers a lot, because it includes taking the sashes out, installing a draught seal system, new sash cords and new hardware. Our sash window overhaul page lists everything it covers.
Locking restrictors
In practice, a restrictor lets the window open a little for ventilation but stops it opening wide. With a key or a thumb-turn, it locks the sash in place. As a result, you can leave a window ajar without leaving it open to anyone.
Some insurers ask for a locking restrictor. However, policies differ, so check your wording first. If you are unsure, send us the wording and we will tell you what we can fit.
We fit restrictors on request, either with other work or on their own. Because the fitting must suit your frame, we check the timber and the sash fit before we start.
Fixing the window first
However, a lock is only as good as the timber it screws into. For example, a rotten sill or a split stile will not hold a fitting. In that case, we repair the timber first. Our sash window repairs page explains how.
However, a broken cord leaves a sash hanging loose. Sash cord replacement from £120 per window restores smooth, balanced movement. Then the catch and restrictor can do their job.
Regular care helps too. For example, our maintenance guide shows how to check catches, cords and paint each year, so small faults do not grow.
What a security visit covers
First, we look at every sash in the house, not only the ones you have noticed. We test each catch, check how far the sashes open, and look at the condition of the timber around each fitting. Then we list what each window needs, because no two windows wear alike.
Because we see the whole picture, we can price the work sensibly. You may find that a few catches and restrictors are enough. Alternatively, a full overhaul may suit older windows better.
French doors and other openings
Doors need security as well, because they are often the weakest opening. We repair, restore and draught proof French doors, and we fit locking sets on request. Our French door repairs page covers that service.
Security and draught proofing together
In addition, a tight window is quieter, warmer and harder to force. So we often combine the two jobs. Draught proofing seals the sashes in their frames. Then the new catch pulls them tight.
Our five-year guarantee covers our labour and the draught-proofing system. Since fitting hardware is part of our labour, that work is covered too.
Listed and conservation homes
On a listed home, fittings need care because the building has special status. We choose hardware that suits the building, and we handle listed work case by case. See listed building sash windows for more.
Insurance and your policy
First, read the security clause in your home insurance policy. Insurers word these clauses differently, and some ask for specific lock types. Then tell us what the wording says, so we can match the fittings to it.
In addition, keep the quote and the invoice we give you. They show what we fitted and when, which helps because your insurer may ask later.
Price
However, security fittings vary in cost with the type and the number of windows. So we quote in writing after a free visit. Our standard rates are on the costs page.
Get a free quote
We visit, check each window and tell you what is needed. Although there is no charge, you are under no obligation to go ahead.
To start, get in touch and mention if your insurer has asked for locks. We cover all Greater London postcodes. We are open Monday to Friday, 08:00 to 18:00.