In 1883, when Villar resigned,[5] Gaudí took over as chief architect, transforming the project with his architectural and engineering style, combining Gothic and curvilinear Art Nouveau forms.

[9] Relying solely on private donations, Sagrada Família's construction progressed slowly and was interrupted by the Spanish Civil War.

[10] In 1939, Francesc de Paula Quintana took over site management, which was able to go on with the material that was saved from Gaudí's workshop and that was reconstructed from published plans and photographs.

Advancements in technologies such as computer-aided design and computerised numerical control (CNC) have since enabled faster progress and construction passed the midpoint in 2010.

[13] In March 2024, an updated forecast reconfirmed a likely completion of the building in 2026, though the announcement stated that work on sculptures, decorative details and a controversial proposed stairway leading to what will eventually be the main entrance is expected to continue until 2034.

[9][20] After Gaudí's death, work continued under the direction of his main disciple Domènec Sugrañes i Gras until interrupted by the Spanish Civil War in 1936.

[21] As of 2006[update], work concentrated on the crossing and supporting structure for the main steeple of Jesus Christ as well as the southern enclosure of the central nave, which will become the Glory façade.

[citation needed] In October 2010, the tunnel boring machine reached the church underground under the location of the building's principal façade.

Chief architect Jordi Faulí announced in October 2015 that construction was 70 percent complete and had entered its final phase of raising six immense steeples.

[37] Starting on 9 July 2017, an international mass is celebrated at the basilica every Sunday and holy day of obligation, at 9 a.m., and is open to the public (until the church is full).

[45] Local residents have concerns about plans to build a large stairway leading up to the basilica's main entrance, unfinished at the time, which could require the demolition of three city blocks: the homes to 1,000 people as well as some businesses.

In common with Catalan and many other European Gothic cathedrals, Sagrada Família is short in comparison to its width, and has a great complexity of parts, which include double aisles, an ambulatory with a chevet of seven apsidal chapels, a multitude of steeples and three portals, each widely different in structure as well as ornament.

[citation needed] Where it is common for cathedrals in Spain to be surrounded by numerous chapels and ecclesiastical buildings, the layout of Sagrada Família has an unusual feature: a covered passage or cloister which forms a rectangle enclosing the church and passing through the narthex of each of its three portals.

With this peculiarity aside, the plan, influenced by Villar's crypt, barely hints at the complexity of Gaudí's design or its deviations from traditional church architecture.

[48][49] Gaudí's original design calls for a total of eighteen spires, representing in ascending order of height the Twelve Apostles,[b] the four Evangelists, the Virgin Mary, and, tallest of all, Jesus Christ.

The central spire of Jesus Christ is to be surmounted by a giant cross; its total height (172.5 metres (565.9 ft)) will be less than that of Montjuïc hill in Barcelona,[52] as Gaudí believed that his creation should not surpass God's.

[citation needed] Plans call for tubular bells to be placed within the spires, driven by the force of the wind, and driving sound down into the interior of the church.

[60] For instance, the three porticos are separated by two large columns, and at the base of each lies a turtle or a tortoise (one to represent the land and the other the sea; each are symbols of time as something set in stone and unchangeable).

The steeples were completed in 1976, and in 1987 a team of sculptors, headed by Josep Maria Subirachs, began work sculpting the various scenes and details of the façade.

He wanted to "break" arcs and "cut" columns, and to use the effect of chiaroscuro (dark angular shadows contrasted by harsh rigid light) to further show the severity and brutality of Christ's sacrifice.

Facing the setting sun, indicative and symbolic of the death of Christ, the Passion Façade is supported by six large and inclined columns, designed to resemble strained muscles.

Each of the four steeples is dedicated to an apostle (James, Thomas, Philip, and Bartholomew) and, like the Nativity Façade, there are three porticos, each representing the theological virtues, though in a much different light.

[needs update][69] To reach the Glory Portico, the large staircase will lead over the underground passage built over Carrer de Mallorca with the decoration representing Hell and vice.

The handles of the door are the letters "A" and "G," forming the initials of Antoni Gaudí, within the phrase no permeteu que caiguem en la temptació ("lead us not into temptation").

Essentially none of the interior surfaces are flat; the ornamentation is comprehensive and rich, consisting in large part of abstract shapes which combine smooth curves and jagged points.

To overcome the unique acoustical challenges posed by the church's architecture and vast size, several additional organs will be installed at various points within the building.

The steeples are decorated with words such as "Hosanna", "Excelsis", and "Sanctus"; the great doors of the Passion façade reproduce excerpts of the Passion of Jesus from the New Testament in various languages, mainly Catalan; and the Glory façade is to be decorated with the words from the Apostles' Creed, while its main door reproduces the entire Lord's Prayer in Catalan, surrounded by multiple variations of "Give us this day our daily bread" in other languages.

Assessments by Gaudí's fellow architects were generally positive; Louis Sullivan greatly admired it, describing Sagrada Família as the "greatest piece of creative architecture in the last twenty-five years.

[5] In 2005, UNESCO extended the inscription for Works of Antoni Gaudí – No 320 bis to include four additional buildings in Barcelona, with item 320-005 listed as two specific sections of Sagrada Família: the Crypt and the Nativity façade.

[29] In October 2018, Sagrada Família trustees agreed to pay city authorities €36 million for a building permit, after 136 years of unlicensed construction.