Preliminary Bat Roost Inspections

What do I need to know about Preliminary Roost Inspections (PRIs)?

A PRI is undertaken as part of the Initial Ecological Assessment when there are buildings (or mature trees) on site that may be impacted by the proposed development works. It is an initial inspection of the building/tree to assess the suitability for it to contain bats, which are both a European and locally protected species. It is a day-time scoping survey that can be undertaken at any time of year.

Bat surveys can be a complicated subject. Contact us to arrange a no obligation site meeting to discuss your requirements and help you understand the process, or download our PDF below for more information.

Why do I need a Preliminary Roost Assessment?

Bat populations have declined drastically throughout Europe (and the world), and as such they are now a protected species in many countries. In Jersey, bats and their roosts are protected under the Conservation of Wildlife (Jersey) Law 2000. Any development which may impact a protected species needs to have ecological consultancy to ensure correct mitigation. 

What does a Prelimenary Roost Inspection involve?

What about costs?

Exact costs will depend on the size of your property, plus the scope and complexity of the proposed works. An inital site meeting will allow us to fully discuss your project and ensure the best value approach. 
Costs from £375* 

*There may also be a charges from Jersey Biodiversity Records Centre and for DNA analysis of droppings 


Further information about bat surveys


The States of Jersey Department of the Environment require all bat surveys to follow the Bat Conservation Trust Best Practice Guidelines (Collins 2016) when undertaking surveys for bats. These guidelines can be found here, but we have produced a summarised version you can download below. 

Bat Surveys and Planning Applications Summary;

Download here

When can this type of survey be undertaken?

This survey can be undertaken at ANY TIME OF YEAR and may be required as part of your Planning Application

What happens next?

If the PRI shows no evidence or suitability for a building (or mature tree) to contain bats, then a simple report is written which may include some precautionary mitigation measures. It will prove that a scientifically robust survey has been undertaken to show that use of the structure/tree by bats is unlikely, in line with best practice guidelines for survey effort. 

If evidence of bats is found or the buildings show ‘suitability’ for these species, then further surveys may be required – see Protected Species Surveys. Further surveys are typically restricted to certain times of the year so it is important to determine if they are needed as early as possible to prevent unnecessary delays to your project.


Whilst having any Planning Condition imposed on one’s proposed development plan can be a source of frustration, Nurture Ecology helped us to navigate the best way to meet the requirements of the Department of the Environment. This was achieved in a timely and pragmatic way, and I have no hesitation in recommending them to either assist with ecological planning conditions or more general requirements

Peter Mossop, Homestead, St Ouen

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