+Before you start the import, you should create a project directory for your
+new database installation. This directory receives all data that is related
+to a single Nominatim setup: configuration, extra data, etc. Create a project
+directory apart from the Nominatim software and change into the directory:
+
+```
+mkdir ~/nominatim-planet
+cd ~/nominatim-planet
+```
+
+In the following, we refer to the project directory as `$PROJECT_DIR`. To be
+able to copy&paste instructions, you can export the appropriate variable:
+
+```
+export PROJECT_DIR=~/nominatim-planet
+```
+
+The Nominatim tool assumes per default that the current working directory is
+the project directory but you may explicitly state a different directory using
+the `--project-dir` parameter. The following instructions assume that you run
+all commands from the project directory.
+
+!!! tip "Migration Tip"
+
+ Nominatim used to be run directly from the build directory until version 3.6.
+ Essentially, the build directory functioned as the project directory
+ for the database installation. This setup still works and can be useful for
+ development purposes. It is not recommended anymore for production setups.
+ Create a project directory that is separate from the Nominatim software.
+
+### Configuration setup in `.env`
+
+The Nominatim server can be customized via an `.env` configuration file in the
+project directory. This is a file in [dotenv](https://github.com/theskumar/python-dotenv)
+format which looks the same as variable settings in a standard shell environment.