Case Study
Timber window energy upgrade
The existing timber window was fitted with thinner glazing that did not provide the level of energy efficiency required for the upgrade.
We specified an A-rated double-glazed unit with a minimum overall thickness of 24 mm. Fitting that unit meant carefully renovating the glazing area of the existing timber frame rather than carrying out a simple like-for-like glass replacement.
Project video
A verified transcript of the spoken commentary has not yet been prepared. This local review draft uses the video only for the work that can be verified visually and the technical facts supplied directly by the owner.
Case summary
The existing thinner glass was not energy efficient enough for the intended upgrade. Replacing it with another thin unit would not have achieved the required improvement.
The upgrade called for an A-rated double-glazed unit with a minimum overall thickness of 24 mm, but the original timber glazing rebate had been formed for thinner glass and did not provide enough space.
A standard like-for-like replacement would have left the original limitation unchanged. The more energy-efficient double-glazed unit required greater glazing depth than the existing timber frame provided.
The frame therefore had to be renovated and adapted before the specified unit could be installed correctly.
The glazing rebate — the part of the timber sash that supports and surrounds the glass — was widened and deepened in a controlled way to create the space required for the minimum 24 mm unit.
The aim was to remove only the timber needed for the new glazing specification while retaining the existing frame.
This work required careful assessment of the timber construction and close control of the width, depth and position of each cut. Removing too little material would prevent the double-glazed unit from fitting; removing too much could unnecessarily damage or weaken the sash.
The close-up footage shows the cutting, measuring and repeated checks used during the renovation.
The video shows the timber sash prepared for access to the glazing area, followed by controlled powered cutting along the rebate. Measurements are taken during the work, and the rebate is progressively adjusted around the sash.
Once the required glazing space has been prepared, the double-glazed unit is positioned in the renovated sash. The final part of the footage shows the visible glazing components being fitted and the glass being cleaned.
The existing timber window was upgraded to accept an A-rated double-glazed unit meeting the specified minimum 24 mm overall thickness. The footage shows the new unit seated in the renovated sash and the visible finishing work completed.
This approach retained the existing timber frame while addressing the glazing-space limitation that had prevented the energy-efficiency upgrade. No unrecorded U-value or wider performance figure is claimed.
The video presents the full visible sequence, from enlarging and measuring the timber rebate through to fitting the double-glazed unit. Audio has been retained with the original work footage.
Where the existing timber is suitable, a carefully planned glazing upgrade can improve the window without automatically replacing the complete frame. Windows Repair Galway can inspect the construction, assess the available glazing space and advise whether this type of renovation is appropriate for the particular window.
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