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Notre-Dame de Paris
Bags 1-9: The Chancel and Chevet of Notre-Dame
Chevet
A semi-circular extension at the eastern end of Gothic cathedrals, housing the apse, ambulatory, and radiating chapels.
Chancel
The sacred area around the altar, within the apse, reserved for clergy, and used for liturgical ceremonies.
We begin our exploration of Notre-Dame de Paris by constructing its chevet, the eastern end of the cathedral that includes the chancel. Work on this section began in 1163, beginning a project that would span nearly two centuries.
The chevet of Notre-Dame exemplifies Gothic architecture, characterized by soaring heights, expansive windows, and intricate stone structures. This complex eastern end comprises the chancel (or choir), the apse, an ambulatory, and radiating chapels. The chancel serves as the liturgical heart of the church, housing the high altar and providing space for clergy and choir members.
The chevet features tall pointed arches and slender columns that draw the eye upward, symbolizing spiritual ascension. Large stained glass windows, supported by ribbed vaults and flying buttresses, allow abundant light and enhance acoustics.
The Chevet of Notre-Dame de Paris
Instructions 1-12: Foundations of the Chevet
Notre-Dame Foundations
Laid in 1163 on Île de la Cité in central Paris.
Engineering Innovations
Advanced deep-pile foundation techniques were developed to secure Notre-Dame on the marshy Seine riverbank.
In these instructions, we begin construction of Notre-Dame de Paris by laying the foundation for its eastern section, the chevet. This iconic Gothic cathedral commenced construction in 1163 under the direction of Bishop Maurice de Sully. The cathedral's foundations were intricately laid on the small Île de la Cité in Paris, presenting a significant engineering challenge due to the marshy ground of the Seine riverbank.
To overcome this obstacle, workers excavated nearly 30 feet (9 meters) into the earth, well below the island's waterline. They constructed massive stone footings to support the immense weight of the planned structure. This process spurred the development of advanced deep-pile foundation techniques, which anchored the massive cathedral securely to the ground.
Watch a short discussion of Notre-Dame's central location on the Île de la Cité
Instructions 13-16: Eastern Courtyard Paving
Cathedral Construction
In 12th century Paris, limestone paving around the chancel prepared the site for Notre-Dame's construction and public use.
Medieval Paris Development
Narrow streets and small buildings were cleared for cathedral expansion, creating the parvis, a key public space.
We now focus on paving the exterior area around the chancel. This space, which would later become part of the cathedral's parvis (forecourt), was central to the life of medieval Paris.
In the 12th century, this area was densely populated with narrow streets and small buildings, many of which were cleared to make way for the cathedral. The paving provided a stable surface for construction activities and helped manage drainage, essential due to the cathedral's proximity to the Seine River.
The original paving likely consisted of limestone slabs, durable enough to withstand heavy foot traffic. As construction progressed, this paved area evolved into a significant public space for gatherings, markets, and civic events. While the current parvis is larger and dates from later periods, the initial paving around the chancel laid the groundwork for connecting the cathedral with the vibrant life of the city.
Instructions 17-20: Black and White Tiling
Chancel Floor Tiling
Installed from 1771-1773, the floor’s pattern overlays medieval tombs, merging symbolism and preservation
Checkerboard Design
The chancel’s black and white tiles symbolize light and darkness.
The distinctive black and white tiled floor of Notre-Dame's chancel was not part of the original 12th-century design but was added during significant renovations in the 18th century.
Between 1771 and 1773, the cathedral's floor was repaved with alternating black and white marble tiles, creating a dramatic checkerboard pattern. This renovation covered most of the existing medieval tombs, effectively preserving them beneath the new flooring.
Symbolically, the contrasting colors represented the duality of light and darkness, a common theme in Christian iconography, often reflecting the interplay of divine illumination and worldly shadow.
The chancel of Notre-Dame de Paris
Instruction 21: High Altar
Notre-Dame High Altar
Positioned at the choir's eastern end, the altar blends modern design with Gothic architecture, emphasizing its liturgical significance.
Historical Transformations
Evolving from medieval to Baroque, the altar was redesigned in the 19th century and modernized in 1989.
In this section, we construct the high altar area of Notre-Dame. The altar is located at the eastern end of the choir, where it meets the apse, underscoring its spiritual and architectural importance. Crafted from marble, it serves as the focal point for liturgical ceremonies and the celebration of the Eucharist. The altar's design has transformed over centuries—from its medieval origins to a Baroque redesign in the 18th century, a 19th-century renovation by Eugène Viollet-le-Duc, and its current modern form installed in 1989.
The High Altar of Notre-Dame de Paris
Instructions 22-37: Base of the Apse Wall
Construction of Notre-Dame Apse
Building the outer wall of the apse, focusing on support for flying buttresses and chapels.
French Gothic Architecture
The apse's design permits taller walls and wide windows, embodying key Gothic elements.
Here we being constructing the outer wall of the apse. The apse, located at the eastern end of the cathedral, is a semicircular or polygonal structure that houses the altar and choir.
Notre-Dame's apse is notable for its harmonious blend of form and function. Its curved shape creates a focal point for worship and symbolizes the embrace of the divine. The outer wall we're building will support a series of radiating chapels, a distinctive feature of French Gothic architecture.
The apse's outer wall also serves as the foundation for the flying buttresses that will support the structure's weight, allowing for taller, thinner walls and larger windows. This innovative architectural feature is key to achieving the soaring heights and luminous interiors characteristic of Gothic cathedrals.
Instructions 38-39: Apse Ambulatory
Notre-Dame Ambulatory
Covered walkway encircling the apse and choir, allows unrestricted movement and connects to radiating chapels.
Architectural Features
Ambulatory designed with arched openings and slender columns, enhancing light and space interaction.
In this section, we build the ambulatory that encircles the apse of Notre-Dame. Later we will extend it around the choir.
The ambulatory is a covered walkway that forms a complete circuit around the choir and apse. It serves as a passage for clergy and pilgrims, allowing movement behind the high altar without disturbing services. This feature is characteristic of larger Gothic churches and cathedrals, facilitating the flow of people and enhancing the building's functionality.
Construction of the ambulatory involves creating a series of arched openings supported by slender columns. These arches form the inner wall of the ambulatory, while the outer wall connects to radiating chapels. This design creates a harmonious blend of spaces, allowing light to filter through and providing access to various areas of the cathedral's eastern end.
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Ambulatory and Chapels of the Chevet of Notre-Dame de Paris
Instructions 38-39: Apse Windows
Rayonnant Gothic Windows
Large clerestory windows added between 1235 and 1270 highlight Rayonnant Gothic style, emphasizing light and height in Notre-Dame's apse.
Structural and Artistic Design
The windows' extensive glasswork and tracery enhance natural lighting and spiritual ambiance, featuring biblical scenes.
The apse features large clerestory windows, added between 1235 and 1270. These windows are a key element of the Rayonnant Gothic style, characterized by an emphasis on light and vertical lines. The design allows for larger openings, flooding the interior with natural light and enhancing the spiritual atmosphere.
The windows are supported by flying buttresses, which provide structural stability while enabling the expansive glasswork. The intricate tracery within the windows forms beautiful patterns that frame the stained glass, depicting biblical scenes and saints. This combination of light and artistry not only illuminates the apse but also serves to inspire worshippers, creating a transcendent experience within the cathedral.
Windows of Notre-Dame's Apse
Instruction 46: Chancel Pillars Construction
Notre-Dame's Gothic Pillars
Supporting the vaulted ceilings, these pillars typify Gothic style with vertical designs and space for luminous windows.
Historical Architecture Impact
Built by Pierre de Chelles in the 13th century, these pillars integrate flying buttresses for increased interior light.
In this section, we build the interior pillars of Notre-Dame's chancel and choir.
These limestone pillars, standing among the black and white tiled floor, are crucial to the cathedral's structure. They support the weight of the vaulted ceilings, transferring the load to the foundation. The pillars' design reflects the Gothic style's emphasis on verticality and light.
Master Pierre de Chelles, who directed the structural work in the late 13th century, ensured systematic stone carving for these columns. Their capitals feature classicized designs. The use of flying buttresses outside allowed for these slender interior pillars, creating more space for windows and enhancing the interior's luminosity. This architectural innovation contributes to the soaring, ethereal atmosphere that defines Notre-Dame's chancel.
Watch an explanation of Notre-Dame's vertical architecture
Instructions 47-57: Walls of the Choir
Rayonnant Gothic Walls
Early 13th-century side walls with large clerestory windows and slender mullions, characteristic of the Rayonnant Gothic style.
Triforium Gallery Details
A narrow passageway below the clerestory, featuring smaller arched openings that enhance depth and provide access.
In this section, we build the side walls and windows of the choir, focusing on the rectangular portion of the chancel.
The choir's side walls, constructed in the early 13th century, exemplify the Rayonnant Gothic style. These walls feature large clerestory windows that allow abundant light into the interior. The windows are divided by slender stone mullions and tracery, forming intricate patterns that support the glass panels.
Below the clerestory, a triforium gallery runs along the length of the choir. This narrow passageway, with its own series of smaller arched openings, adds depth to the wall structure and provides access for maintenance. The combination of clerestory windows and triforium creates a visually striking elevation, emphasizing the vertical lines characteristic of Gothic architecture and enhancing the sense of height within the cathedral.
Chœur de Notre-Dame de Paris (1669)
Instructions 58-73: Chancel Roof Supports
Chancel Roof Structure
"La Forêt" is a 13th-century timber frame with trusses, purlins, and king posts supporting the roof and vaulting.
Restoration Techniques
Post-2019 fire, traditional carpentry methods are crucial for preserving the structural integrity of the roof.
The chancel roof is supported by an intricate timber frame structure known as "la Forêt" (the forest). This network of wooden trusses, dating back to the 13th century, distributes the roof's weight and protects the stone vaulting below.
Key components of the roof support include principal rafters, which form the basic triangular shape; purlins that run horizontally for added support; collar ties connecting opposite rafters to prevent spreading; and king posts extending from the apex to provide stability.
This wooden framework, while hidden from view, is essential for maintaining the structural integrity of the chancel. Following the 2019 fire, traditional carpentry techniques have been used to carefully preserve and reconstruct this vital element.
Charpentes (timber frames) of Notre-Dame
Instructions 74-83: Upper Apse and Choir Construction
Triforium Window Design
Builds include the intricate triforium windows, emphasizing Gothic layering and visual depth between lower arches and clerestory.
Architectural Techniques
Focus on vaulted ceilings and supportive frameworks typical of Gothic cathedrals, enhancing rainwater drainage and light influx.
In this section, we begin building the upper levels of the apse and choir.
We start with the roof over the ambulatory, which forms the lowest level of the apse's exterior. This sloping roof allows rainwater to drain away from the building's core.
Above this, we construct the triforium windows, located between the lower level and the clerestory. These windows are smaller and more decorative, adding a sense of depth and layering to the cathedral's interior while maintaining the Gothic aesthetic.
Interior of Notre-Dame's Choir, South View
Instructions 84-100: Choir Roof and Buttress Foundations
Gothic Architecture Features
Features steep-pitched choir roof, flying buttresses for support, enabling larger windows and taller walls.
Structural Elements
Addition of arches provides weight distribution and sets the base for Notre-Dame's iconic vertical silhouette.
Now we construct the exterior roof over the choir and continue building upwards.
The choir roof, typically made of lead-covered timber, protects the vaulted ceiling below. Its steep pitch, characteristic of Gothic architecture, efficiently sheds rain and snow. We also complete the second level of roofing, which extends from the apse.
We begin constructing the flying buttresses, a key feature of Gothic engineering. These arched exterior supports transfer the outward thrust of the vaulted ceiling to the outer walls, allowing for taller, thinner walls and larger windows.
Additionally, we add more arches that will support the third level. These arches, part of the building's skeletal framework, distribute weight and create the soaring vertical lines typical of Gothic cathedrals. This stage sets the foundation for the upper levels of Notre-Dame's iconic silhouette.
Notre-Dame de Paris from the east, circa 1860s
Instructions 101-103 Clerestory Windows and Walkway
Clerestory Windows
Sits above the triforium, critical for interior illumination and a key part in maintaining the Gothic ideal.
The third level of windows, known as the clerestory, sits above the triforium gallery. These large windows are essential for illuminating the interior, embodying the Gothic ideal of a light-filled space.
The feature that resembles a balcony is actually a clerestory walkway. While not a true balcony for public access, it allows maintenance and cleaning of the upper windows.
Notre-Dame de Paris from the east at night
Instructions 104-116: Clerestory Roof
Notre-Dame Roof Structure
Lead-covered timber frame constructed with medieval techniques shields and supports the cathedral's structural integrity.
Materials Used in Reconstruction
Approximately 1,000 oak trees from French forests are used to recreate the dense network of trusses known as "la Forêt."
This phase involves constructing the top roof of the chancel, which covers the clerestory level and is essential to Notre-Dame's iconic silhouette.
The roof features a steep, lead-covered timber frame that protects the stone vaulting below. This structure, known as "la Forêt" (the forest) due to its dense network of wooden trusses, is being recreated after the fire of 2019 using traditional medieval techniques.
Approximately 1,000 oak trees, carefully selected from French forests, are utilized for this reconstruction. The timber frame consists of main trusses and secondary supports, all designed to evenly distribute the roof's weight.
Notre-Dame de Paris from the east, showing the chancel roof
Instructions 117-119: Chancel Flying Buttresses
Notre-Dame Flying Buttresses
Essential for counteracting vaulted ceilings' outward thrust, buttresses stabilize walls, supporting larger windows and taller structures.
This section focuses on the construction of the flying buttresses supporting the chancel of Notre-Dame.
Flying buttresses are essential structural elements that counteract the outward thrust generated by the cathedral's vaulted ceilings. At Notre-Dame, these buttresses were among the earliest examples of their kind, introduced in the 12th century to stabilize the walls and allow for taller structures and larger windows.
The construction involves creating arched structures that extend from the upper portions of the walls to massive piers. Each buttress is designed to absorb and redirect lateral forces downward, ensuring the stability of the chancel. The intricate design not only serves a functional purpose but also enhances the aesthetic appeal of the cathedral’s exterior.
Flying buttresses of the chancel at Notre-Dame de Paris