What is EIA how why does it matter?
An EIA or Environment Impact Assessment is a process that accesses the proposed development project to see how it will affect the environment, both at the local level and on a much wider and global scale. EIA is required for certain types of development under the European legislature and the results of the EIA will have a huge effect on how the planning authority sees your application.
If you are unsure of how EIA will affect your project, it may be a good idea to first talk to someone at the planning authority so that you have a better insight and know how to plan your project. Of course, you can always amend your application and reapply as often as you are denied but if you can get it done right the first time, by all means do so.