The Times newspaper reports, in an article by Nicola Woolcock, that the chapel at Lancing College will be completed over 150 years after it was begun:
A stunning and distinctive place of worship towering over the landscape has remained unfinished for more than a century amid wrangles over cost and design, but now the end is in sight. Not the Sagrada Familia in Barcelona but the chapel at Lancing College, a leading private school on the edge of the South Downs, that has Evelyn Waugh, Sir Tim Rice and Sir David Hare among its alumni.
Work began on the neo-gothic structure — the tallest and arguably most imposing school chapel in the world — in 1868, some 20 years after the college was founded by Nathaniel Woodard, the parish priest. It is said that he gazed out across the River Adur one day after a service and, with its clear views across the West Sussex valley, he immediately realised he had found the spot. […]
The chapel was eventually dedicated in 1911, despite one side being finished with a sheet of corrugated metal. That was replaced with a wall featuring a vast stained glass rose window in 1978, dedicated by the Archbishop of Canterbury in a ceremony attended by the Prince of Wales. The west wall remained incomplete, however, with temporary doors and filled in arches and, until recently, it appeared that plans to finish the 27 metre (90ft) high building were a lifetime away.
Although not quoted, Waugh describes his impression of the chapel when he was taken to enroll in the school in 1917. This is from A Little Learning, his autobiography:
…We had been sent some photographs of the buildings, but they failed to prepare us for the dramatic dominance of the chapel which filled the scene before us. Mr Woodard had paid dear for his choice of site. The foundations, it was said, lay deeper below ground than the chalk groining above. He intended all his buildings to be a reaffirmation of the Anglican Faith, and Lancing Chapel was to be the culminating monument of his design, proclaiming his purpose in the clearest tones. The great building was unfinished, but the east end, which confronted us gave no evidence of the ruinlike, temporarily abandoned areas which lay behind. The glass seen from outside was greenish as though enclosing an aquarium. Visiting preachers often compared the apse to the prow of a ship. I know no more spectacular post-Reformation ecclesiastical building in the kingdom. (CWEW, v. 19, p. 80).
According to The Times, the building schedule ambitiously calls for completion in 2020:
The west wall remained incomplete, […] with temporary doors and filled in arches and, until recently, it appeared that plans to finish the 27 metre (90ft) high building were a lifetime away. Now an ambitious £3.5 million plan to attach the chapel to the independent boarding school has been scaled down with a different vision — a £1.2 million project to create a new porch offering a more fitting entrance. Only £350,000 is left to raise, thanks to donations and legacies, and the building is due to be completed at the end of 2020 and rededicated in early 2021. […] The chapel is made from Horsham stone, a local sandstone susceptible to erosion, especially given its lofty position only miles from the sea. […] The new porch will be built in Somerset stone, which is more durable.
To make donations to the completion fund and see renderings of the new west end of the chapel, go to this link.
The other incomplete ecclesiastical structure mentioned prominently in the article is the Church of Sagrada Familia in Barcelona. Waugh also wrote a detailed description of that project in his early travel book Labels (Chapter VII). Although not mentioned, another notable example of an unfinished church is the Cathedral of St John the Divine on Morningside Heights in New York City. It was begun in 1888 (20 years after Lancing Chapel) and several portions remain unfininshed, the most noticeable being the north tower of the west front. And as for musical examples, how could they have overlooked Schubert’s Symphony No. 8, nearly always referred to as the Unvollendete (“Unfinished”)?