The cost of a “bat shed” to protect a species in woodland along the new HS2 high-speed line has risen to more than £100m, HS2’s chair has revealed. The 1km-long mesh structure will be built where the London-Birmingham high-speed line emerges from a tunnel in Buckinghamshire, to protect a colony of Bechstein’s bats. Describing it as a “blot on the landscape” built with “no evidence” that bats were at risk from the trains, Sir Jon Thompson said: “This shed, you’re not going to believe this, cost more than £100m.” Thompson, questioned at an industry conference about the huge costs of building HS2, said the railway’s budget was driven partly by legal constraints and the demands of conflicting agencies, as well as government indecision, with more than 8,000 different permits needed along the route. He gave the example of the Sheephouse Wood bat protection structure, adding: “We call it a shed.” Thompson told the Rail Industry Association conference in London: “To build a railway between Euston and Curzon Street in Birmingham, I need 8,276 consents from other public bodies, planning, transport, the Environment Agency or Natural England. They don’t care whether parliament did or didn’t approve building a railway.” He said the “bat shed” was his favourite example of the problems caused. The Bechstein’s bat was “generally pretty available in most of northern Europe, western Europe”, he said. “But nevertheless, under the Wildlife Act, 1981, it’s deemed to be a protected species in the UK, this bat, even though there’s lots of them.” The bat is rare in the UK and deemed to be “vulnerable” in Europe, according to the IUCN conservation network’s red list. Thompson added: “No evidence, by the way, that high-speed trains interfere with bats, but leave it on one side.” HS2 had to obtain a licence from Natural England, which approved the bat mitigation structure, before asking planning permission from Buckinghamshire county council, he said. “So when we go to [the] council and say: ‘Would you like to give us planning permission for this blot on the landscape that costs £100m’, of course, the answer to that is, you’ve got to be joking, right? Why would [they] like this eyesore? “So now I’ve got two different bodies. One says I have to do it. The other one says: ‘No chance’. So what do you do? I reach for the lawyers and the environmental specialists and hydrologists and so on and so forth. It stretches out the time. I spend hundreds of thousands of pounds trying to do something, and then in the end, I win the planning commission by going over [the county council’s] head.” Thompson said there were “loads of those examples”, concluding: “People have this simplistic way of saying: ‘Oh, you’ve gone over the budget. Oh, yeah. OK. But do people think about the bat?’” Natural England’s chief operating officer Oliver Harmar said: “Natural England has not required HS2 to adopt this structure, nor advised on the design or cost. Our input has been to comment on whether the proposed mitigations will work. That is our duty under the Habitats Regulation. “HS2 Ltd is required by legislation to avoid harm to the environment and it is for them to make choices, consider risks and factor in costs when deciding how to do this, whether by avoiding species and sites protected for nature or by investing in mitigation to limit harm where the route passes through sensitive sites.” According to HS2, more than 20 alternative proposals were considered but discounted as even more costly or failing to protect the bats and therefore illegal. A Treasury-commissioned review in 2021 undertaken by DfT, Defra and Arup concluded the “bat shed” remained the most viable solution. The HS2 chair said that, to reduce costs, “the government needs to be a better client and make quicker decisions … They can take six months to make a decision most of us would make across the boardroom on a Friday. There are problems across the system.” Ministers last month said that the scale of HS2’s budget overspend to build the line from London to Birmingham was still unclear. Louise Haigh, the transport secretary, said the cost overrun could be between £10bn and £20bn. HS2 Ltd gave the government an upper projection of £74bn last September for the first phase. The chancellor, Rachel Reeves, has nonetheless committed to funding the tunnels into Euston, after the project was trimmed and mired in uncertainty last year by Rishi Sunak.