Bats are a protected species and if their presence is anticipated in an existing building a survey has to be undertaken and the recommendations of the survey incorporated into the development. We are in the bat survey window (May to August) so it shouldn't hold things up for too long, unless there are roosting bats in the buildings.
Yes there is upcoming breaking news on a big money bat transfer The surveys have to take place in the roosting season
I know someone who bought a house and turned out they had bats in the loft. He had some bat enthusiasts camping outside his house for like a week monitoring the numbers. They had to have a short break in-between them coming back and doing another survey and he managed to get them out of his loft in the meantime. Depending on numbers they can insist you provide accommodation for them I believe with a set square footage. They had indicated to him that effectively he was going to have to build something the size of a granny annex in his back garden at his own expense.
There is nothing wrong with wheelie bins and paddling pools. The dimensions were perfect for my sports science team.