<P> Computer - aided design technology has been used to accelerate construction of the building . Current technology allows stone to be shaped off - site by a CNC milling machine, whereas in the 20th century the stone was carved by hand . </P> <P> In 2008, some renowned Catalan architects advocated halting construction, to respect Gaudí's original designs, which although they were not exhaustive and were partially destroyed, have been partially reconstructed in recent years . </P> <P> Since 2013, AVE high - speed trains have passed near the Sagrada Família through an underground tunnel that runs beneath the centre of Barcelona . </P> <P> The tunnel's construction, which began on 26 March 2010, was controversial . The Ministry of Public Works of Spain (Ministerio de Fomento) claimed the project posed no risk to the church . Sagrada Família engineers and architects disagreed, saying there was no guarantee that the tunnel would not affect the stability of the building . The Board of the Sagrada Família (Patronat de la Sagrada Família) and the neighborhood association AVE pel Litoral (AVE by the Coast) had led a campaign against this route for the AVE, without success . </P>

How much did it cost to build the sagrada familia