Kattolyhtyjen

Kattolyhtyjen are roof lanterns, a type of architectural feature consisting of a small tower or lantern that rises above the main roofline to light and ventilate the spaces beneath. The structure typically has glazed walls on multiple sides and a separate roof, and it is supported by the building’s framing. They differ from flush skylights in that kattolyhty on the roof projects above the roof surface and may include decorative elements.

Historically, kattolyhtyjen became a common feature in Finnish and Nordic architecture from the late 18th century onward, especially on farmhouses, manor houses, churches, and public buildings. They provided daylight to interior stairs, attics, or central halls and facilitated air exchange in climates with long winters. Variations range from simple square or rectangular lanterns to more elaborate cupola-like forms, sometimes with a balcony or viewing opening.

Construction and materials typically combine timber framing with glazing on the sides, a small pitched or hip roof, and flashing to prevent leaks. The lantern is integrated into the roof structure with attention to weatherproofing and insulation to maintain interior comfort.

Preservation and significance: Many surviving kattolyhtyjen are valued as architectural heritage and are the subject of restoration to maintain their historical appearance and structural integrity. In restored examples, the lanterns contribute to the character of both rural and urban landscapes and illustrate regional building traditions.

Note: kattolyhtyjen is the plural form of kattolyhty in Finnish, used when discussing multiple such structures.