Double-Glazed Window Guide

How to Open a Double-Glazed Window Fully

The method of opening the double glazed window depends on the window opening system installed in the window frame.

Casement windows open outwardly, tilt-and-turn windows are capable of opening in two different modes, and sliding windows slide sideways on rails.

Please follow the instruction below for the correct identification of the window to avoid forced operation and damage.

Quick Answer

Start by Identifying How Your Window Opens

Casement Usually hinged at the side and opens outwards.
Tilt & Turn Tilts for ventilation or opens fully inwards.
Sliding Moves horizontally along a track.
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The Short Answer

Most Double-Glazed Windows Can Be Opened Further Once the Correct Mechanism Is Released

Unlock the window normally and determine what type of window you have; casement, tilt and turn, or sliding.

If the sash does not reach its intended point of operation, there may be a restrictor or obstruction preventing it from doing so, and should not be forced open.

Step One

Identify the Type of Double-Glazed Window

Consider the manner in which the sash is hung on the window frame and the direction in which it operates when you move the handle.

01
Opens Outwards

Casement Windows

Casement windows are usually hinged to the window frame and open outwardly.

Casement windows usually have a handle that is connected to a locking mechanism at the point where the sash opens.

How to open a casement window ↓
02
Two Opening Modes

Tilt-and-Turn Windows

The tilt-and-turn window is one that usually opens in two ways depending on how you use the window handle.

It may open inward from the top to allow ventilation or open inward from the side to get a bigger opening.

How to open a tilt-and-turn window ↓
03
Moves Sideways

Sliding Windows

The sliding window does not swing on hinges like the usual windows, but instead opens horizontally.

Usually, one sash slides in front of or behind the other part of the window.

How to open a sliding window ↓
Casement Windows

How to Fully Open a Casement Window

It is common to see casement windows in UK homes, and they usually open outward. It is important to follow the movement of the window naturally without putting much force on it when the sash gets stuck.

01
Unlock

Unlock the Handle

Unlock the window and move the handle to its normal open position.

The position of the handle may differ from one window system to another.

02
Open

Push the Window Outwards

Grasping the handle, carefully open the sash away from the frame.

Open the window until it opens to the required point or to the limit of its hinge or restrictor.

03
Check

Check the Friction Stays and Restrictors

Casement windows may have friction stays or opening restrictors that influence the distance of travel of the sash.

In case the window stops at the same point each time, see if there is an installed restrictor that is controlling the movement of the sash.

Tilt & Turn Windows

How to Fully Open a Tilt-and-Turn Window

The tilt and turn windows have the handle controlling two different opening mechanisms. Use the handle cautiously and ensure that the sash is completely closed when moving from one position to the other.

01
Handle

Select the Correct Handle Position

The tilt and turn windows use different positions of the handle for ventilation and opening.

In most cases, one position tilts the top part of the sash inwards whereas the other opens the entire sash inwards.

02
Clearance

Check the Space Around the Window

Ensure that there are no curtains, blinds, decorations or furniture in the opening area when you want to open the window completely.

03
Open

Open the Sash Inwards

Once you have the handle at the right position, open the sash gently by pulling it towards you.

Support larger opening sections when moving them and avoid forcing the handle or the sash if the mechanism is not working.

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Important for Tilt-and-Turn Windows

Do not keep changing the position of the handle while the sash is partially opened. If the mechanism seems not to be working, close the sash and support it instead of forcing the handle.

Sliding Windows

How to Fully Open a Sliding Window

Sliding windows slide open horizontally on a track rather than swing open away from the frame.

01
Unlock

Release the Window Lock

Ensure the lock is all the way out before trying to operate the sash.

02
Slide

Slide the Sash Along the Track

Grab hold of the proper handle or part of the sash and then slide the window horizontally along the track.

Do this until the window is open as far as it normally opens.

03
Check

Check Stops and Latches

Some sliding windows have stops or catches that prevent further motion.

If the sash suddenly stops while sliding, look at the track and any hardware attached to it, rather than force the lock.

Troubleshooting

Why Won't My Double-Glazed Window Open Fully?

If the window opens but fails to unlock, then there are various problems which may be preventing the window from operating.

01

Window Restrictor

There could be a restrictor installed in the window to ensure that the sash cannot open past a certain point.

The window may be operating exactly as intended.
02

Dirt or Debris

Grime on the hinges, track or the frame edge can hinder the operation of the window.

Check accessible areas for obvious obstructions.
03

Stiff or Damaged Handle

If the handle is very stiff, loose or spinning, it could mean that there is something wrong with the handle or locking mechanism.

Do not keep forcing a resistant handle.
04

Hinge or Friction Stay Problem

Hinges that are damaged or worn out will make it hard for the sash to operate or it may catch on the frame.

Look for dropping, rubbing or uneven movement.
05

Obstruction in a Sliding Track

Sliding windows may be hard to operate when there is dirt in the track and along the sliding sash.

Clean accessible tracks carefully.
06

Window Misalignment

The sash could have become misaligned and caught on the frame or failed to release the locking points.

Persistent catching may need professional attention.
Important

Don't Force a Window That Won't Open

However, if a double glazed window becomes hard to move, using more force is not usually the right thing to do.

Stop if Something Feels Wrong

This can cause more stress on the locking system, hinges, and even the frame itself.

First check if there is something clearly blocking the way, restrictors fitted, or if the sash is sticking in the frame.

Window Restrictors

A Restrictor May Be There for a Reason

Sometimes, restrictors are installed on windows intentionally. They can be adjusted to control the distance of the sash opening.

One should never remove the restrictor just to achieve a larger opening unless one knows why it has been installed.

Keep Things Moving

Tips for Smooth Window Operation

Such simple tests can assist in the early detection of any minor issues before the window gets harder and harder to operate.

01

Inspect Handles and Locks

Make sure to test periodically for loose, stiff, or otherwise unusual feeling handles.

02

Keep Tracks Clean

Clean out any dirt or debris found in the sliding mechanism and around the opening sections of the frame.

03

Check Hinges

Identify any apparent wear or looseness, or evidence that the opening sash is beginning to rub against the frame.

04

Use Suitable Lubrication

If lubrication is necessary, make sure to use the proper lubricant for the specific window hardware.

Still Having Problems?

When Should You Get Help With a Window?

A window which still cannot be opened even after checking for any obstruction could be facing issues with its hinges, handle, locking system, or alignment.

One should think about having the window inspected if there is any issue with the handle spinning or moving properly, the sash has fallen down, the window jams when closing or opening or the locking system does not unlock properly.

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Common Questions

Opening Double-Glazed Windows: FAQs

How do I open a double-glazed window fully?

First, determine the type of window being worked on, whether it is a casement, tilt-and-turn, or sliding window. Unlatch the window and operate it using the normal procedure for that specific window type. When the sash gets stuck, check whether there is a restrictor or obstruction instead of trying to force it open.

Why does my window only open a small amount?

It might be that there is a restrictor installed on the window. Restrictors are purposely designed to prevent the movement of the sash to a certain distance and are not necessarily faulty.

How do you fully open a tilt-and-turn window?

Tilt-and-turn windows have different handle positions when in ventilation mode and full opening mode. With the sash fully closed, insert the handle in the proper position for full opening and gently pull the sash inside. This will depend on the window system.

Why is my double-glazed window difficult to open?

This could be because of dirt or debris, worn-out hinges, a stiff locking system, damaged hardware, or misalignment of the sash. Do not try to force the window open if it is difficult to do so.

Can I remove a window restrictor to open the window further?

A restrictor could have been installed purposely to restrict the opening of the window. Do not remove or disable the restrictor until you understand its purpose and are sure it is necessary.

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