Posted: 22/04/2017 at 20:30
Bats fly around everywhere, what is the nature of your overgrowth? Bats don't roost at ground level (except in caves etc) you won't find them in residence in the nettle patch or an unpruned shrub.
I have a Pipistrelle nursery roost in the house roof most years. If we wanted to re-roof we wouldn't do it while they were there and we'd leave access for them to come back for the next breeding season. You wouldn't be expected to live in a leaking house. There are ways around it all. Bats aren't pests, they're part of our rapidly diminishing native wildlife.
I wonder if the owners have left a wild area because they are interested in wildlife. It's a good way to go.