How long do bat surveys and reports remain valid?

Infographic - How long does a bat survey last?

How long do bat surveys and reports remain valid?

You’ve commissioned and received your bat report – will you need to update it before your project starts?

This can be a really important and tricky consideration.  It is always a good idea to understand constraints that bats might have on a project early on, but the surveys will need to be in date when you apply for your planning application and, if one is needed, a bat licence.

The Chartered Institute of Ecology and Environmental Management (CIEEM) provide an advice note on this[1], which is really helpful as it provides some clarity and an even approach across different planning authorities.

Does your bat survey need to be updated?

Obviously different sites can have different circumstances.  In general though, any report that is less than one year old should be considered valid.

Surveys and reports that are between twelve and eighteen months old are also generally considered to be valid unless, for example, site conditions have changed – e.g. there have been works on site, a building has become disused, trees felled etc.

Between eighteen months and three years , an update is required. Often a repeat site walkover survey could cover this for a preliminary roost assessment.

After three years, it will be safest to start from scratch with surveys and get an updated baseline for your project.

[1] CIEEM, 2019. Advice Note on the Lifespan of Ecological Reports and Surveys.