I know, I know, the Duomo di Milano cathedral took something like 400 years :) I really hope Sagrada Familia will be completed one day, despite the lack of the original drawings. it' one of the most amazing buildings ever designed, so it has to be finished, but even if not.. stil beautiful :)
I spent several happy hours there in June and one of the reasons for the lack of drawings is that some were destroyed by the republican side in the civil war. Gaudi getting run over by a tram probably didn't help either. The amount of detail is just astounding.