It is not the survey that causes the problem. It is the time of year you can do it. Miss the window and your application stalls for months.
Bats are fully protected in the UK. That protection applies to permitted development just as it applies to full planning permission. If your building might support bats, you need a survey. That is not the part most people struggle with.
The part that catches people out is the timing. Bat surveys can only be carried out during a specific window in the year. Submit your application at the wrong point in the calendar and you will be asked for a survey you cannot commission for months.
An agricultural barn that has been standing for any length of time is exactly the kind of structure bats use. Roof spaces, gaps in cladding, structural voids. The ecologist will look at all of it.
If the preliminary assessment triggers the need for further surveys, and those surveys cannot be done until the season opens, your application is effectively paused. In some cases that pause runs to six months or more.
Disturbing a bat roost without the correct licence is a criminal offence. That is not a planning matter. It is a wildlife law matter. The consequences are serious and they apply to the landowner, not just the contractor.
Knowing when to commission the survey, what the survey needs to cover, and how to present the results as part of your application is the difference between a smooth process and one that stalls before it starts. The guide covers all of it.
A complete end-to-end guide for farmers and landowners converting an agricultural building under Class Q Permitted Development. Bat surveys, highways, open hay barns, eligibility, the 56-day rule, and everything in between. Based on direct experience. Three applications. Two locations. All granted.
Get the guide — £67