Building techniques and structure
The constructions of Notre Dame started 1163 with the choir between 1163 until around 1177 and the new high altar was consecrated in 1182. By finishing the eastern end of the church first a temporary wall could be erected allowing the chapter to use it while the rest of the building took shape. They built the façade of the church in three levels, which was the old Romanesque style, but with pointed arches in the new gothic style. This gave the front a more horizontal. Notre Dame was completed in 1272.
For Notre Dames structure, 21 hectares of oak was used, the roof was made using 1.320 lead plates weighing over 210,000 kg. The wheelbarrow was invented to make it easier to carry equipment around. Cranes, winches and steeple jacks (a type of human hamster wheel) was also used to raise materials for construction.
Several different people worked on the project, Bishop Maurice de Sully made the decision to build in gothic style encouraged by the King Louis VII. The entire population participated in the project, offering money, labor or knowledge. The masons, carpenters and the glassworkers supervised laborers, chore men, apprentices, specialist workers and volunteers.
To support the heavy roof and the immense windows (that let light into the building) the walls head to be built very high and strong. The builders made all the construction weight supported by pillars instead of the wall, which now featured tall wide windows. To distribute weight from the stone and the roof the oval vaults inside and the flying buttresses outside was used.
The stone arches helped support the walls and pushing back in against the weight of the six-part groin vault of the roof pushing out. Big heavy column capitals were used so that your eyes would be drawn upwards to Heaven.
When the Notre Dame was finished the builders replaced the windows with bigger ones, except for the walls right next to the crossing, where the...