1 Portland Row, Dublin

Historic sash windows are an integral part of Ireland’s architectural heritage. They were the predominant window style from the 1720s and are found in protected structures across the country. They not only exhibit exquisite craftsmanship but also provide a glimpse into the past.

The Significance of Sash Windows in Ireland’s Protected Structures

Sash windows have been an architectural feature in Ireland for centuries. They were hugely popular during the Georgian and Victorian eras, in particular, reflecting the fashion for classical architecture of the time. These windows exhibit a unique design, incorporating vertically sliding panels that allow for controlled ventilation and the maximum glazing for natural light. Indeed, they provide the perfect balance between illumination and ventilation. They came to Ireland via Great Britain and the earliest sash windows in Ireland are in Kilkenny castle dating to 1680. Before this time there was no glass making on the island of Ireland. The original architects and builders designed with these windows in mind, the number, size and proportions as well as colours and placement.  They are inherent to the facade of the building and in some cases, the streetscape. To alter these now would be to change the building. For this reason, the windows are protected by legislation under the Planning and Development Act Part IV since the year 2000.

Legislation and Protection

This aforementioned Planning and Development Act legislation in Ireland plays a crucial role in safeguarding protected structures, including the preservation of historic sash windows. Under this legislation, owners and architects are obligated to protect and maintain the original features of these structures, including their windows. Failure to comply with the legislation can result in penalties and legal consequences.

Restoration Techniques for sash windows in Ireland’s protected structures

Restoring historic sash windows requires a delicate balance between preserving their originality and ensuring their functionality and continued longevity. Windows should be looked at on a case-by-case basis and as part of the building as a whole. There is no ‘one size fits all’ solution when it comes to conservation.

1. Repairing or replacing damaged timber components: Over time, sash windows may suffer from rot or decay. Our skilled craftsmen carefully assess the condition of the timber and determine what repairs or replacements are necessary. The use of ethically sourced and compatible timber is essential. If we are replacing a whole piece we would typically use utile moahogany, whereas splice repairs are carried out using Accoya. The original windows are most commonly made of a slow grown pitch pine which has incredible longevity. Accoya is also a softwood, but it has been treated by a process of acetylation which gives it great durability and less movement when
2. Reglazing and preserving original glass: Historic sash windows often still contain the original glass. This would have been either crown or cylinder mouth blown glass which has beautiful imperfections that cast a soft, dappled light on the interiors of the building as well as safeguarding the handcraft of our previous generations. It is our duty to safeguard this history for the future. However, with an ever increasing emphasis on energy efficiency in buildings, windows are one of the most vulnerable elements to change, despite only 10-15% of heat loss occuring through them.
3. Upgrading for energy efficiency: While preserving the historical integrity of sash windows is crucial, it is also important to address energy efficiency concerns. Restoration projects often include the installation of secondary glazing or draught-proofing measures to enhance insulation without compromising the original design. The Irish government also recently produced new guidelines for energy efficiency in traditional buildings which includes an excellent chart of other simple U-value improvements that don’t need the glass replaced. However, in some situations, if the original glass is not present or if it is broken, the conservation officer may advise that slim double glazing or vacuum glazing can be used to replace it. This will be decided on a window by window basis and may require planning permission.

Maintenance and Care

Once restored, it is essential to implement regular maintenance and care practices to ensure the longevity of historic sash windows. Some key considerations include:

1. Routine cleaning: Regular cleaning helps prevent the accumulation of dirt and grime, which can lead to deterioration over time. Care should be taken to use mild cleaning solutions and avoid abrasive materials that may damage the window surfaces. We recommend simply wiping over with a damp cloth.
2. Periodic inspections: Regular inspections allow for the early identification of any maintenance issues. We recommend to annually check for signs of rot, decay, damaged paint, defective ironmongery. putty damage, damaged draught seals, worn cords or loose components. Prompt action can prevent further damage and costly repairs down the track.

Preserving the originality of sash windows while ensuring their functionality requires a careful balance between historical authenticity and modern practicality. Owners and architects can achieve this balance by considering the following approaches:

Restoring and maintaining historic sash windows in Ireland’s protected structures is a responsibility that falls upon the custodians. By adhering to the Planning and Development Act legislation and implementing appropriate restoration techniques, we can preserve the architectural charm and cultural significance of these windows. With regular maintenance and care, these windows will continue to grace our protected structures for generations to come, serving as a testament to Ireland’s rich architectural heritage.

If you have a protected structure and would like to find out more about the windows, contact us for information on [email protected] or 046-9023323. We work across the island of Ireland and our quality workmanship is recognised by architects, contractors and homeowners alike.