they started building the church in 1882 and they used neon gothic for the designs. at the age 31 he was lead achitect, he used neon for his trademark modernist style that was based on forms found in nature. he died in 1926 Gaudí was constantly improvising and changing the design while construction was going on, he left few designs and models. And most of these were destroyed during the civil war in 1936. when they finished building the church it should fit up to 13,000 people in the church, amagine how big the church is. And also sagrada famiia was originally concevied by the catalon publisher Josep bocabella as a work of expections for the city's increasing revolutionary. one of the points of them building the church was La Sagrada Familia is a striking example of Gaudi's unique Art Nouveau architecture and is filled with religious symbolism and meaning.