Timber-framed house in Schnersheim

The Building

Building pre-intervention

Building post-intervention

The house is located in a dense village, at the edge of one of the major national road leading to Strasbourg. It is surrounded by other typical farms, built at the same time between the 17th and the 18th century. As the building is not located in a conservation area, the validation of the works by the Alsatian architectural review board was not required by regulation. Besides the house is not listed : it is a simple farmer house, as thousands of others all across the Alsace Region. But they are all being threatened with destruction.

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The Solution

Solution post-intervention

What is the Solution?

Thanks to the pictures from the beginning of the 20th century, it was possible to restore the windows and the outside shutters as they were originally and with the approval of the Alsatian architectural review board, which was in charge for validating these works not because of regulation but because of a grant application from the owner. Technically, all the original single-glazed wooden windows were replaced by double-glazed ones and the windows frames are all in oak and some are arched. Besides, those windows are made of four casements that can be opened independently.

Why Does it work?

Since the windows before rehabilitation were not the original ones, had no significant heritage value and lack thermal performance, replacing them was considered the best option The windows were all replaced, but the new ones are identical to the original ones (based on historical study of the building) except the glass, which is a double-glazing dedicated to heritage buildings. The new windows had to maintain the original proportions of the windows, therefore not be too thick while supporting the weight and size of a double-glazing.

PROS

The material is local wood
This solution was an opportunity to work with a local carpenter and this measure led to the development of a prototype that was approved by the Alsatian architectural review board
Improved aesthetic Preservation: The Uw was downsized by 50% while maintaining the heritage aesthetic and architectural value of the building

CONS

These windows have a Uw of 2.14 W/m².K, which is a low performance compared to the double glazing installed in other parts pf the building like the cellar and the attic (Uw = 1.3 W/m².K).
The windows required custom-made work

Window Type before retrofit

Casement Window

Window glass type

Double-glazing

Window frame material

Oak

Window position

In the middle

Shading

Type: plain panel shutters Position: exterior Material: wood Size: shutters of the same shape as the window openings

Health issue

information not available

Installation Method

The first window was a prototype, in order to prove to the Alsatian architectural review board than thin double glazing will not alter heritage significance of the building. The windows were then all manufactured in the carpenter's workshop.

Moisture Management and Technical Compatibility

Double glazing, care taken to installation (especially concerning airtightness between the frame and the wall) and efficient and well-maintained dual-flow ventilation ensure that no moisture problem will occur.

Airtightness

Care was taken concerning airtightness between the frame and the wall when installing the windows. Joints were also placed between sash and frame, as a common practice when manufacturing new windows.