Paneled windows that will withstand the scrutiny of preservationists and maintain the historical character of buildings

High-quality replicas of old double-sashed windows are gaining increasing popularity among architects who strive to respect and restore the original appearance of historical and monument-protected buildings. Their use can achieve a perfect harmony between aesthetics and functionality, thanks to an impeccable imitation of the original appearance, the use of traditional materials, and appropriate craftsmanship. In this article, we will take a closer look at modern double-sashed windows and their ability to meet the demands of preservationists while also fulfilling contemporary requirements for living comfort.


When replacing windows in monuments, in heritage zones, and monument reserves, it is necessary to obtain a binding opinion from the heritage conservation department. The heritage conservation department evaluates and examines the drawing documentation of the existing and proposed state of the windows, the expert assessment of the existing openings, including color sampling, the reason for replacing the windows with a description of the exact quantity of replaced elements. In such cases, the heritage authorities usually insist on replacing the windows with precise replicas of the original wooden windows. Often, these are double-sashed windows, where it is necessary to preserve their original historical appearance, including all decorative elements.

In protected zones (which includes a large part of Prague), the requirement for obtaining a binding opinion does not apply. This often leads to the mistaken belief that the choice of windows for buildings in this area does not matter at all. However, as stated in the European Charter of Architectural Heritage: "Monuments can lose a large part of their character if their environment changes." Therefore, it is at least advisable to approach the replacement of windows individually and sensitively concerning the overall architectural, urban, and historical context of the surrounding buildings and the visual integration of the structure into the views of heritage zones and reserves.

Historic Double-Sashed Windows from Creative Windows and Doors

Our Historic double-sashed windows are based on the requirements of customers and preservationists. Their design allows for the installation of not only standard single glass but also insulating double glazing. Wooden double-sashed windows can be complemented by various window handles, sills, and decorative elements such as latches, capitals, bases, and flaps, etc. The production of double-sashed windows takes place on modern carpentry machines, enabling the production of precise replicas or copies of old windows. Thus, the new double-sashed windows can replace the original historical windows.

At Creative Windows and Doors, we have extensive experience in dealing with preservationists and we ensure the preparation of the project including drawing documentation in order to obtain a binding opinion for the replacement of windows in buildings under heritage protection. Our success rate in obtaining a positive opinion is 100%.

Specifications and Technical Parameters of Historic Windows

• As a standard, the windows are glazed with insulating double glazing in the outer sash and single glazing in the inner sash.
• The heat transfer coefficient whole window is Uw = 0.98 W/(m²K) with double glazing 4/12/4 in the outer sash and 4 mm glass in the inner sash.
• Air sound insulation is Rw = 46 dB.
• With their appearance, divisions, and proportions between glass and wooden parts, these windows closely resemble original handcrafted historical windows, thus meeting the strict requirements of preservationists.
• The windows have no visible joints on the frames and sashes.
• Same visible width for the inner and outer sashes.
• The inner sash is without a glazing bead from the interior.
• The possibility of several types of profiles for sashes and frames based on original historical windows.
• No euro profiles for sashes, frames, glazing beads, mullions with a large amount of silicone around the glass, which is typical for euro imitations of double-sashed windows.

Today's models of double-sashed windows thus not only preserve the historical style of buildings but also save costs for heating and overall improve living comfort, as they achieve excellent thermal insulation properties.

Example of Execution by Creative Windows and Doors

The exceptional project Residence Helenika offers beautiful views of the city and Prague Castle. The developer Aston Group decided to preserve the original character of the First Republic villa as designed by the prominent architect Max Spielmann in 1924. The reconstruction focused on maximizing the use of original elements, which were complemented by the latest technological and functional features and luxury standards of execution.

Similarly high standards were understandably placed on the windows and balcony doors. For the Residence Helenika project, double-sashed windows and Historic balcony doors were chosen. Our company provided the manufacturing and installation of a total of 83 replicas of historical windows and balcony doors.

The final appearance of the double-sashed windows and balcony doors was very carefully consulted with preservationists. This mainly involved maintaining the exact profiling, divisions, decorative elements, fitting of frames and sashes, and, last but not least, the selection of brass fittings and ornate hinges.

Even in the preparatory phase, we can create a sample window for similar projects, which will serve for assessment by preservationists.

Sample double-sashed window made for assessment by preservationists

You can view more photos from other realizations here >

Visit us at our showroom in Prague 8

Come and touch the windows in person. We would be happy to welcome you to our showroom at: Sokolovská 551/131, Prague 8. It is open from Monday to Friday between 08:00 and 16:30 (by prior arrangement also later). Here you can view our offer, which, in addition to double-sashed windows, also includes aluminium, wooden, wood-aluminium, and possibly even plastic windows. We will be happy to advise you on selecting windows that reflect the style of your house, meet insulation requirements, and other current customer demands. You can also contact us by phone or via email.

(+420) 777 874 899
info@oknacreative.cz
https://oknacreative.cz/

Ing. Josef Liška
owner of Creative Windows and Doors