Diocletian Window [patched] < RECOMMENDED • CHECKLIST >

While the style originated in antiquity, it was largely forgotten until the Italian Renaissance. In the 1560s, repurposed the ruins of the Baths of Diocletian’s frigidarium (cold room) into the Basilica of Santa Maria degli Angeli, preserving the original massive windows.

★★★★☆ (4/5) Deducting one star only for its limited domestic applicability and potential energy performance issues without modern glazing. diocletian window

The , also commonly known as a thermal window , is a classic architectural element defined by its large, semicircular shape divided into three lights (compartments) by two thick vertical mullions. Typically, the central light is wider than the two flanking it, creating a balanced, monumental appearance that has graced everything from ancient bathhouses to modern train stations. Historical Origins: The Baths of Rome While the style originated in antiquity, it was