diff --git a/scripts/build.sh b/scripts/build.sh
new file mode 100755
index 0000000..d735a8b
--- /dev/null
+++ b/scripts/build.sh
@@ -0,0 +1,100 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SOURCE_ISO="${1:-}"
+
+REPO_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+BASE_DIR="$(cd "$REPO_DIR/.." && pwd)"
+BUILD_DIR="$BASE_DIR/build"
+WORK_DIR="$BUILD_DIR/work"
+OUTPUT_DIR="$BUILD_DIR/output"
+MOUNT_DIR="/mnt/fedora-iso"
+
+usage() {
+  echo "Usage: $0 /path/to/source.iso"
+}
+
+check_input() {
+  if [[ -z "$SOURCE_ISO" ]]; then
+    usage
+    exit 1
+  fi
+
+  if [[ ! -f "$SOURCE_ISO" ]]; then
+    echo "Error: ISO not found: $SOURCE_ISO"
+    exit 1
+  fi
+}
+
+check_dependencies() {
+  for cmd in rsync xorriso; do
+    if ! command -v "$cmd" >/dev/null 2>&1; then
+      echo "Error: missing dependency: $cmd"
+      exit 1
+    fi
+  done
+}
+
+prepare_dirs() {
+  mkdir -p "$BUILD_DIR" "$OUTPUT_DIR"
+  rm -rf "$WORK_DIR"
+  mkdir -p "$WORK_DIR"
+}
+
+mount_iso() {
+  sudo mkdir -p "$MOUNT_DIR"
+  sudo mount -o loop "$SOURCE_ISO" "$MOUNT_DIR"
+}
+
+unmount_iso() {
+  sudo umount "$MOUNT_DIR" || true
+}
+
+extract_iso() {
+  echo "Extracting ISO..."
+  mount_iso
+
+  trap unmount_iso EXIT
+
+  sudo rsync -a "$MOUNT_DIR"/ "$WORK_DIR"/
+  sudo chown -R "$(id -u):$(id -g)" "$WORK_DIR"
+
+  unmount_iso
+  trap - EXIT
+}
+
+patch_grub() {
+  echo "Installing Tuxflotte GRUB configuration..."
+
+  cp "$REPO_DIR/grub/EFI-BOOT-grub.cfg" \
+     "$WORK_DIR/EFI/BOOT/grub.cfg"
+
+  cp "$REPO_DIR/grub/boot-grub2-grub.cfg" \
+     "$WORK_DIR/boot/grub2/grub.cfg"
+}
+
+verify_workdir() {
+  echo "Verifying workdir..."
+
+  grep -q "Tuxflotte" "$WORK_DIR/EFI/BOOT/grub.cfg"
+  grep -q "Tuxflotte" "$WORK_DIR/boot/grub2/grub.cfg"
+
+  echo "GRUB verification passed."
+}
+
+main() {
+  check_input
+  check_dependencies
+  prepare_dirs
+  extract_iso
+  patch_grub
+  verify_workdir
+
+  echo
+  echo "Build preparation complete."
+  echo "Work dir: $WORK_DIR"
+  echo
+  echo "ISO creation will be added in the next step."
+}
+
+main "$@"