The construction of Notre Dame began in 1160, at a time when architecture was changing from an older Romanesque style, so called because it borrowed heavily from the designs of ancient structures of the Roman and Byzantine empires. Sanctuaries were a simple rectangle design, with a the nave (the place where the worshipers congregated) stretching out from a rounded apse that stood at the eastern end of the room. Over the 300 years or so of the Romanesque period, churches began to add wider cross-sections just west of the apse, making the sanctuary into the shape of a cross. These portions of the sanctuary, extending to the north and south, were known as transepts. Gothic churches would continue this basic layout of the building, but they would sometimes extend the transepts out even wider than the floor plan shown here:
|Gothic cathedral floor plan. From wikipedia.org.|
Romanesque churches were also noted for the arches and columns that supported their high ceilings. In the 12th century, however, architects discovered that pointed arches (rather than rounded or semi-circular ones) could support even higher buildings. These new arches allowed for Gothic churches to be taller, creating a more vertical perspective to the overall worship space.
|Rounded arches of the Romanesque style. From wikipedia.org|
|Gothic pointed arches in Notre Dame. From wikipedia.org.|
In order to keep these stratospheric Gothic walls from falling over, designers came up with another innovation: the flying buttresses. These exterior supports were first used at Notre Dame, and they transferred a significant amount of stress from the walls themselves, allowing them to be thinner.
|Drawing of a flying buttress at Notre Dame. From wikipedia.org.|
|14th-century flying buttresses at Notre Dame. From wikipedia.org.|
The higher and thinner walls allowed for more windows, which let in more light to the church building. Gothic churches, therefore, were able to experiment with new techniques in stained glass. One of the most striking designs is the rose window, which is a characteristic of the Gothic style.
|Rose Window at Notre Dame. From wikipedia.org.|
Higher ceilings, thinner walls, and more light meant that Gothic churches took advantage of the worshipers' visual capacities more than their auditory ones. Christian worship would mirror the adaptations to the designs of the buildings, changing into an event that is seen more than heard. Priests would say the mass, but parishioners who gathered many yards away would not be able to hear what was said. They instead watched intently for the moment when the consecrated host was lifted up to be gazed at. Just like today, when churches are designed to be more functional than beautiful, Christian worship has always adjusted itself to match the values that are reflected in its buildings.