Going a little over budget or coming into slight delays is to be expected with any large-scale infrastructure project, but these overblown megaprojects take it to the next level. From the Olympic stadium that wasn’t ready in time for the Games, to the metro line extension which cost four times its original budget, read on to see the uber-delayed global megaprojects that broke the bank. All dollar values in US dollars.

The nicknamed ‘Big O’ stadium was rightly renamed the ‘Big Owe’ due to the building coming in at 13 times the original cost estimate. There was a manic scramble to get it finished in time for the Games on 17 July 1976, with 3,000 staff working 24 hours a day in the final months, and even then it wasn't quite finished in time. Reportedly, construction workers were blocking the way of the first athletes coming into the stadium for the opening parade.

During the build, architect Roger Taillibert and Montreal's mayor Jean Drapeau, who had commissioned the stadium, faced multiple major obstacles. There were several labour strikes that wiped 30% off the available work time, a tripling of the price of structural steel, as well as corruption among officials. Three decades later, CBC reported that the $1.5 billion debt from the 1976 Summer Games had finally been paid off.

In 1990 the legendary Hubble Space Telescope was launched into orbit, 353 miles above the Earth. At the time, the BBC reported how the Hubble would provoke “a drastic revision of the shapes, sizes and content of galaxies” – having already drastically revised its budget and deadline for launch.

The Hubble took 20 years to build – at least seven years longer than planned. Plus, it cost three times the original estimate coming in at $1.5 billion at the time, which is the equivalent of $2.9 billion (£2.4bn) in today's money. Despite the cost, technical problems persisted even after the launch, including the malfunctioning of the solar panels which powered the telescope and flaws in the mirrors which help produce images. 

Cost overruns for megaprojects are incredibly common: the McKinsey Global Institute estimates that global infrastructure spending will account for 4% of global GDP between 2013 and 2030, the bulk of which is funnelled into large-scale projects. The Channel Tunnel is a prime example, running 80% over budget at a cost of £4.65 billion, which would be $14.5 billion (£12bn) today. It wasn't until the year 2011 that the tunnel finally began making a profit, 17 years after it was opened.

Broadly speaking, the tunnel has been a success, providing an essential link for trade and passengers between the UK and mainland Europe. However, fires, faulty power lines and other engineering issues have all added to the financial woes of Eurotunnel, the company that built and opened the channel. Eurotunnel was slipping towards bankruptcy in 2007 before the company was restructured and shareholders exchanged their stock for shares in a new company, Groupe Eurotunnel.

When Denver’s new airport was finally complete, 16 months late, it was hailed as an economic catalyst by proponents and a legally dubious, colossal waste of money by critics. The New York Times reported that the project had cost $4.9 billion at completion, equivalent to $8.2 billion (£6.8bn) in today's money. This made it three times over budget – leading to the project's own financers filing suits. 

Huge overspends resulted from multiple setbacks to planning and construction. Perhaps the single most costly failure was, ironically, the airport’s key selling point – an ultra-modern, fully automated baggage system. It initially malfunctioned and shredded bags, costing more than $100 million to get into working order. Since then, the airport has been the subject of a host of conspiracy theories, from the theory that markings on the airport floor are satanic symbols, to the idea that its underground bunkers might be a secret lair.

Known as one of Denmark’s biggest ever construction projects, the Great Belt Fixed Link certainly had a great cost. It carried a hefty price tag of DKK 21.4 billion in 1988, which is equivalent to $5.9 billion (£4.9bn) today. The link consists of a suspension bridge and rail tunnel between Zealand and the island of Sprogø, and a second bridge between Sprogø and Funen.

The idea to build a connection between Denmark’s islands was suggested as early as the 1850s. Yet it wasn’t until 1986 that plans were officially approved, with building work starting two years after that. Despite the fact the project’s deadline was 1993, the East Tunnel opened five years late, largely due to flooding which damaged boring machines used in construction.

London Underground is the oldest underground metro system in the world, with parts of it operating since 1863. Yet it’s the newer sections which have caused controversy, due to the enormous costs they incurred: the Jubilee line extension, which began in 1989, cost more per mile to build than the Channel Tunnel. All told, the tube line extension was £3.3 billion in 1999, equivalent to $6.8 billion (£5.6bn) in today’s money.

The 10-mile extension, stretching from central London to Stratford, was originally meant to cost £900 million and open by 1996. However, signalling issues, poor management and technical delays put a hold on the project. What’s more, electricians working on the extension became increasingly annoyed by the delays and demanded higher pay, which only added to the problem of an ever-increasing budget. 

A project that’s been mired in controversy from the get-go, the idea for the Three Gorges Dam on the Yangtze River, China, was proposed in 1919 by politician Sun Yat-Sen. But it wasn’t until the mid-1950s that the idea was given serious attention, and due to the Chinese civil war, building work didn’t start until 1994. The largest hydroelectric power plant in the world, it was built by 40,000 workers over the course of 12 years. It was the subject of rumours on social media recently, with images circulating that showed the dam at risk of collapse, but officials denied the claims.

During its construction the project wasn’t short of critics either. Damaging ecosystems and displacing 1.2 million people, as well as submerging entire villages in order to be built, before and after pictures like these show the dramatic change in the landscape it has caused. Plus, the project cost more than four times the original budget of $8.35 billion: it was reported to have cost $37.23 billion in 2009, the equivalent of $44.5 billion (£36.8bn) in today’s money.

Built to be the pride of Scotland, this project came in three years late and 10 times over budget at a total cost of £414 million, which would be $681 million (£564m) in today's money. To add insult to injury, recent reports have suggested that the building may only have a remaining "estimated useful life" of 44.5 years, meaning that by 2060 it may need a massive refit.

Designed by Spanish architect Enric Miralles, the project wasn't without controversy. Lord Fraser of Carmyllie, a prominent Scottish politician, launched a public inquiry into the construction in 2004. His conclusions were that the handling of construction, by everyone from consultants to contractors and MSPs, ought to have been better managed in order to avoid the massive costs and delays. Despite criticisms, the unusual building has attracted critical acclaim, being awarded the 2005 Stirling Prize for the best building in the UK.

Widely known as the most expensive highway in US history, this megaproject ballooned from a budget of $2.8 billion to a total spend of $14.8 billion, although in July 2012 the Massachussetts Department of Transportation estimated that the actual cost was more than $24 billion (£19.9bn). What's more, it was finished eight years behind schedule, although many sections of the road had been in operation before the project was fully completed in December 2007.

Since opening, the development continues to receive mixed responses. On one hand, it's been mired by controversies, the most prominent of which was the leaking of seawater onto tracks during construction in 1991, causing a ceiling panel to fall onto a car and killing a passenger. On the other hand, the project is widely thought to have had a positive impact on the development of the city, turning it into a real estate and manufacturing hub.

America's most expensive megaprojects

During the early 2000s economic boom in Spain, Galicia’s former leader, Manuel Fraga, set out to build a sprawling complex of six buildings dedicated to showcasing Galician culture. He enlisted the help of American architect Peter Eisenman and set a budget of €129 million for the entire build. In 2011 when it was still only half-built, it was reported that the building had already cost four times more than planned, at €400 million ($448.6m/£371.4m).

Galicia's flagship cultural project now comprises four large empty buildings and two big holes in the ground. In 2013, Spanish newspaper El País estimated that the complex would set the taxpayer back at least another €170 million ($191m/£158m) – unaffordable in a time of austerity. With the upkeep and millions more dollars haemorrhaged on unpopular exhibitions, the Galician government decided to end work and so the project remains incomplete. 

Why did the Sochi Olympics cost 325% more than budgeted, setting Russia’s taxpayers back $51 billion (£42.2bn)? In a word, corruption. This was the most expensive – and controversial – Olympics in history due to corruption being endemic in the Russian construction industry. Two members of the opposition party, Leonid Martynyuk and Boris Nemtsov, claimed in a 2013 report that up to $30 billion (£24.8bn) of the budget had gone missing in "kickbacks and embezzlement" to Putin's close associates. 

Although the project was technically finished in time, it came at a high cost to the workers. Human Rights Watch reported that some 16,000 migrant workers were employed on the project, working 12-hour shifts, seven days a week under immense pressure to get it finished in time, often being paid as little as $1.80 (£1.50) an hour. What's more, some infrastructure remained unfinished at the start of the Games, including hotels without lobbies, working elevators or running water.

Costing twice its original budget, opening three years late and offering a far more limited network than originally planned, the tram system in Edinburgh, Scotland, wasn’t exactly a hit with the city's residents. Construction began in 2007, with the network supposed to encompass several lines including a route between Leith and Newhaven. 

Yet when the budget was blown on building the central line – which operates between the city centre and Edinburgh airport – other routes were scrapped. In June 2014, the tram system finally opened. Despite jubilant responses from many early passengers, members of the city’s council were keen to voice their reservations. Not least of which was the loss of trade to many local businesses, due to a 10-month closure of Princes Street during construction.

Three years before the opening game of the Brazil World Cup, the São Paulo arena set to host the match hadn't left the drawing board. Fast forward to 1 June 2014, 11 days before the World Cup's opening match was due to kick off, and the Arena Corinthians was reportedly only able to be filled to three-quarters of its capacity for the final test match, with two temporary seating areas unfinished.

From China's Great Wall to the US interstate highway: the most expensive megaprojects ever

Brazil spent $15 billion (£12.4bn) in total, including $3 billion (£2.5bn) on new and refurbished stadiums – three times the budget. Up to 90% of the money for the stadiums came from the public purse, despite former president Lula da Silva’s promise that all stadiums would be privately financed. While the stadiums were finished on time, only six of the 35 promised public transportation projects were completed on schedule. 

Built on the site of the former World Trade Center in New York, the Oculus transit hub was designed to replace the destroyed Port Authority Trans-Hudson (PATH) station, as well as serving as a memorial to the 3,000 people who lost their lives in the 9/11 attacks. While it’s been praised for its cutting-edge architectural design – with wing-like roof panels evoking a dove in flight – not everyone has been pleased with the project.

It was opened to the public in 2016, seven years behind schedule. Not only that, it came at a total cost of $4 billion, double the original estimate. Former New York Governor George Pataki had insisted on keeping the No. 1 subway line open during construction, which had added $355 million to the costs, plus the Port Authority in charge of the project had rejected around half a million dollars in potential savings.

It’s been dubbed the airport with half a million errors. Supposed to have been finished in 2012, Berlin’s Brandenburg airport finally opened in 2020. Among the problems that caused delays were a lack of shopping space, which meant a new floor had to be added on; chaotic electrical cabling, which had to be replaced; and the escalators being built too short.

The project was started in 2006, but there have been many issues with management and contractors hired on the project. It cost more almost three times as much as planned – €7 billion ($7.9bn/£6.5bn) – compared to the original budget of €2.4 billion. On top of all that, when it did finally open the COVID-19 pandemic meant very few people actually used it.

Unveiled in 2003, The World is an artificial archipelago of 300 islands off the coast of Dubai. The islands are arranged in the shape of the world map, with each one representing a certain country. The megaproject was developed by Nakheel Projects, the Dubai property developer behind popular tourist attractions such as Palm Island. But as the global financial crisis hit in 2008, The World came to a grinding halt, leading Guardian journalist Oliver Wainwright to describe it as "Dubai's ultimate folly."

Problems have plagued The World ever since. In 2009, it was suggested that some of the islands were sinking into the sea, while the owner of the island representing Great Britain was jailed for fraud. As of 2022, the majority of the islands remain untouched, though construction of the $5 billion (£4.1bn) Heart of Europe islands began in 2019 and was supposedly due to open in 2020. Only the Lebanon island is currently open for business, with restaurants, swimming pools, and a beach club some of the attractions on offer. It's also possible to hire the island for exclusive events such as weddings or private parties – though unsurprisingly this doesn't come cheap, at a cost of AED 50,000 ($13.6k/£10.2k) for 10 hours.

Budget-busting megaprojects that are coming soon – or are they?