How to replace a broken window glass?

How to replace a broken window glass

How to replace a broken window glass?

Did a glass in your window break? No problem; in this short guide, we will explain how to replace a broken window glass and how much the operation costs. Inconveniences are often just around the corner; in many cases, the glass doors and windows pay the price. Thanks to the proverbial fragility of this material, you usually have to replace cracked or broken glass inside a home.

The operation is often unfortunate because a minor distraction could cause cuts and injuries to the people involved. For this reason, it is good to carry out each step with care and attention. Are you also in a similar situation and wondering how to replace the window glass that has just broken? In this article, we explain how to carry out the operation and how much it costs if you decide to rely on a glazier instead.

How to replace broken window glass

If you have to deal with the glass of a broken window and have decided to replace it, here are the operations to carry out step by step.

Removing broken glass

Wear protective gloves and remove pieces or splinters in the frame that houses the broken glass.

With the help of a scraper, clean the frame well from the minor glass residues left on the surface.

Remove the frame that held the glass in place. For a wood frame, you’ll need pliers or pliers to remove the nails holding the window in place. In the case of an aluminum frame, on the other hand, a lever with a screwdriver to lift the structure and the underlying rubber gasket.

If there is any glue or grout residue, sand the surface to prepare it for installing the new window.

How to fit the new glass

Take the measurements of the frame to purchase the new glass plate. The advice is to remove at least a couple of mm so that the glass enters quickly.

As for the thickness, it could be helpful to take a fragment of the broken plate with you to the glazier so that he can provide you with a new one in all respects the same.

Please insert the new glass into the frame and secure it with putty, silicone, or nails.

Then put the fixture back in its place of origin, ensuring it is firmly in its position.

Wait at least 24 hours before removing any glue or grout residues and, if necessary, painting the frame.

How much does it cost to replace a broken window glass

If you want to avoid DIY as much as possible and go to a professional instead, know that replacing the broken glass is relatively inexpensive. The price depends on the size and type of slab requested (single or double).

In principle, however, to replace a 65 cm x 130 cm window glass in Italy, you will find yourself spending between 40 and 80 euros. On the other hand, the replacement of double glazing has a fixed cost of between 100 and 150 euros per square meter.

Replacing Windows Glass: the three limits you hadn’t considered

I make a minor premise; the information in this article is valid only if the replacement of the glass concerns particularly dated windows and is done for reasons of energy efficiency.

It is clear that if the change is justified by breakage or, in any case, by some functional defect, the replacement is the correct way (especially if the window is under warranty).

Let’s get to the main question

The new generation double glazing is characterized by much better insulating and energy performance than glass from 20 or 30 years ago. The improved performance results in greater thicknesses and weights on a structural level. And this is precisely the point: would the old frames adequately support the new glass plates?

New glass is heavier

The first problem lies in the difference in weight. The old windows were probably calibrated based on the importance of the original panes. Still, there is no certainty that, from a mechanical point of view, the existing structure could support a more significant weight because the excess stress to which the frame and hardware are subjected could cause time problems in the opening/closing mechanism.

New glasses are thicker

Then there is another problem: the old window was designed considering a specific thickness of the glass for reasons similar to the previous ones. The new generation windows, on the other hand, to perfectly accommodate the windows, are born with thicker frames… How to solve this thickness gap?

A viable way is to mount glasses with thinner channels (or spacers) to adapt the glass to the measurements of the old window. But given that the thickness of the glass affects the energy performance, reducing the thickness of the conduit penalizes the performance itself. As they say, “we’d be at the end of the day”… the insulating properties would not be up to par anyway.

Alternatively, the professional called upon to assemble the new panes could work the load-bearing structure of the frame to increase the space necessary to accommodate the new glass. Still, in this case, the labor cost would inevitably increase, nullifying the initial attempt to contain the expenses.

New glasses do not make up for any other defects

The last consideration concerns the other elements affecting energy efficiency, which cannot be improved by replacing the glass. Specifically, I am referring to a possible incorrect installation, to the possibility that the fixed and mobile parts of the window do not match perfectly or damaged (or even wholly absent) seals.

All these defects favor drafts, and the new glass can in no way remedy these situations.

Is it better to replace window glass or change windows directly?

In short, installing new glass on old frames is equivalent to “putting on a patch.” The final result would be unsatisfactory in the face of costs that are, in any case, negligible.

To improve your home’s energy performance, the best solution is to replace the windows, benefiting from the tax deductions made available by the state.


Thanks to qualified staff, any operation can be carried out, even in narrow spaces and heights. Also available is a vast fleet of trucks with cranes and numerous suction cups to assemble windows safely and quickly.


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