diff --git a/docs/development/plugin-triggers.md b/docs/development/plugin-triggers.md
index 81a14ae57..a001ab3fa 100644
--- a/docs/development/plugin-triggers.md
+++ b/docs/development/plugin-triggers.md
@@ -173,6 +173,21 @@ set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 # TODO
 ```
 
+### `builder-create-dokku-image`
+
+- Description: Allows modification of the configured dokku-image
+- Invoked by: `dokku deploy`
+- Arguments: `$BUILDER_TYPE` `$APP` `$SOURCECODE_WORK_DIR` `$DOKKU_IMAGE`
+- Example:
+
+```shell
+#!/usr/bin/env bash
+
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+
+# TODO
+```
+
 ### `builder-detect`
 
 - Description: Allows overriding the auto-detected `herokuish` builder in favor of a custom one. Dockerfile gets lowest builder precedence.
@@ -191,9 +206,9 @@ if [[ -f "$SOURCECODE_WORK_DIR/project.toml" ]]; then
 fi
 ```
 
-### `builder-create-dokku-image`
+### `builder-dokku-image`
 
-- Description: Allows modification of the configured dokku-image
+- Description: Allows modification of the used dokku-image.
 - Invoked by: `dokku deploy`
 - Arguments: `$BUILDER_TYPE` `$APP` `$SOURCECODE_WORK_DIR` `$DOKKU_IMAGE`
 - Example:
@@ -206,11 +221,26 @@ set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 # TODO
 ```
 
-### `builder-dokku-image`
+### `builder-image-is-cnb`
 
-- Description: Allows modification of the used dokku-image.
-- Invoked by: `dokku deploy`
-- Arguments: `$BUILDER_TYPE` `$APP` `$SOURCECODE_WORK_DIR` `$DOKKU_IMAGE`
+- Description: Checks if an image is cnb-based
+- Invoked by: unit tests
+- Arguments: `$APP` `$IMAGE_TAG`
+- Example:
+
+```shell
+#!/usr/bin/env bash
+
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+
+# TODO
+```
+
+### `builder-image-is-herokuish`
+
+- Description: Checks if an image is herokuish-based
+- Invoked by: unit tests
+- Arguments: `$APP` `$IMAGE_TAG`
 - Example:
 
 ```shell
diff --git a/plugins/20_events/builder-image-is-cnb b/plugins/20_events/builder-image-is-cnb
new file mode 120000
index 000000000..5178a749f
--- /dev/null
+++ b/plugins/20_events/builder-image-is-cnb
@@ -0,0 +1 @@
+hook
\ No newline at end of file
diff --git a/plugins/20_events/builder-image-is-herokuish b/plugins/20_events/builder-image-is-herokuish
new file mode 120000
index 000000000..5178a749f
--- /dev/null
+++ b/plugins/20_events/builder-image-is-herokuish
@@ -0,0 +1 @@
+hook
\ No newline at end of file
diff --git a/plugins/builder/.gitignore b/plugins/builder/.gitignore
index 6f788ece8..1dd54d973 100644
--- a/plugins/builder/.gitignore
+++ b/plugins/builder/.gitignore
@@ -7,4 +7,4 @@
 /install
 /post-*
 /report
-/builder-detect
+/builder-*
diff --git a/plugins/builder/Makefile b/plugins/builder/Makefile
index b8a598628..2b9139e04 100644
--- a/plugins/builder/Makefile
+++ b/plugins/builder/Makefile
@@ -1,5 +1,5 @@
 SUBCOMMANDS = subcommands/report subcommands/set
-TRIGGERS = triggers/builder-detect triggers/core-post-extract triggers/install triggers/post-app-clone-setup triggers/post-app-rename-setup triggers/post-delete triggers/report
+TRIGGERS = triggers/builder-detect triggers/builder-image-is-cnb triggers/builder-image-is-herokuish triggers/core-post-extract triggers/install triggers/post-app-clone-setup triggers/post-app-rename-setup triggers/post-delete triggers/report
 BUILD = commands subcommands triggers
 PLUGIN_NAME = builder
 
diff --git a/plugins/builder/src/triggers/triggers.go b/plugins/builder/src/triggers/triggers.go
index 56c623a05..25fba8921 100644
--- a/plugins/builder/src/triggers/triggers.go
+++ b/plugins/builder/src/triggers/triggers.go
@@ -21,6 +21,14 @@ func main() {
 	case "builder-detect":
 		appName := flag.Arg(0)
 		err = builder.TriggerBuilderDetect(appName)
+	case "builder-image-is-cnb":
+		appName := flag.Arg(0)
+		image := flag.Arg(1)
+		err = builder.TriggerBuilderImageIsCNB(appName, image)
+	case "builder-image-is-herokuish":
+		appName := flag.Arg(0)
+		image := flag.Arg(1)
+		err = builder.TriggerBuilderImageIsHerokuish(appName, image)
 	case "core-post-extract":
 		appName := flag.Arg(0)
 		sourceWorkDir := flag.Arg(1)
diff --git a/plugins/builder/triggers.go b/plugins/builder/triggers.go
index 8a0b7f5af..0ce1e6454 100644
--- a/plugins/builder/triggers.go
+++ b/plugins/builder/triggers.go
@@ -26,6 +26,28 @@ func TriggerBuilderDetect(appName string) error {
 	return nil
 }
 
+// TriggerBuilderImageIsCNB prints true if an image is cnb based, false otherwise
+func TriggerBuilderImageIsCNB(appName string, image string) error {
+	if common.IsImageCnbBased(image) {
+		fmt.Println("true")
+	} else {
+		fmt.Println("false")
+	}
+
+	return nil
+}
+
+// TriggerBuilderImageIsHerokuish prints true if an image is herokuish based, false otherwise
+func TriggerBuilderImageIsHerokuish(appName string, image string) error {
+	if common.IsImageHerokuishBased(image, appName) {
+		fmt.Println("true")
+	} else {
+		fmt.Println("false")
+	}
+
+	return nil
+}
+
 // TriggerCorePostExtract moves a configured build-dir to be in the app root dir
 func TriggerCorePostExtract(appName string, sourceWorkDir string) error {
 	buildDir := strings.Trim(reportComputedBuildDir(appName), "/")
diff --git a/plugins/common/functions b/plugins/common/functions
index a7ef0324d..3e0b6daf0 100755
--- a/plugins/common/functions
+++ b/plugins/common/functions
@@ -357,41 +357,19 @@ is_image_cnb_based() {
   declare desc="returns true if app image is based on cnb"
   declare IMAGE="$1"
 
-  if [[ -z "$IMAGE" ]]; then
+
+  if [[ "$("$PLUGIN_CORE_AVAILABLE_PATH/common/common" --quiet image-is-cnb-based "$IMAGE")" != "true" ]]; then
     return 1
   fi
-
-  CNB_STACK_ID="$("$DOCKER_BIN" image inspect --format '{{ index .Config.Labels "io.buildpacks.stack.id" }}' "$IMAGE")"
-  if [[ -n "$CNB_STACK_ID" ]]; then
-    return 0
-  fi
-
-  return 1
 }
 
 is_image_herokuish_based() {
   declare desc="returns true if app image is based on herokuish or a buildpack-like env"
   declare IMAGE="$1" APP="$2"
-  local DOKKU_APP_USER
-  local USER_VALUE
 
-  if [[ -z "$IMAGE" ]]; then
+  if [[ "$("$PLUGIN_CORE_AVAILABLE_PATH/common/common" --quiet image-is-herokuish-based "$IMAGE" "$APP")" != "true" ]]; then
     return 1
   fi
-
-  if is_image_cnb_based "$IMAGE"; then
-    return 0
-  fi
-
-  if [[ -n "$APP" ]]; then
-    DOKKU_APP_USER=$(plugn trigger config-get "$APP" DOKKU_APP_USER || true)
-  fi
-  DOKKU_APP_USER=${DOKKU_APP_USER:="herokuishuser"}
-
-  # due to how the build process works, all herokuish images have the Environment variable USER=$DOKKU_APP_USER
-  USER_VALUE="$("$DOCKER_BIN" image inspect --format '{{range .Config.Env}}{{if eq . "USER='"$DOKKU_APP_USER"'"}}{{println .}}{{end}}{{end}}' "$IMAGE")"
-  [[ "$USER_VALUE" == "" ]] && return 1
-  return 0
 }
 
 get_docker_version() {
diff --git a/plugins/common/src/common/common.go b/plugins/common/src/common/common.go
index 4b4c078dc..25095fde1 100644
--- a/plugins/common/src/common/common.go
+++ b/plugins/common/src/common/common.go
@@ -32,6 +32,21 @@ func main() {
 		if !common.IsDeployed(appName) {
 			err = fmt.Errorf("App %v not deployed", appName)
 		}
+	case "image-is-cnb-based":
+		image := flag.Arg(1)
+		if common.IsImageCnbBased(image) {
+			fmt.Print("true")
+		} else {
+			fmt.Print("false")
+		}
+	case "image-is-herokuish-based":
+		image := flag.Arg(1)
+		appName := flag.Arg(2)
+		if common.IsImageHerokuishBased(image, appName) {
+			fmt.Print("true")
+		} else {
+			fmt.Print("false")
+		}
 	case "scheduler-detect":
 		appName := flag.Arg(1)
 		if *global {
diff --git a/tests/unit/core_1.bats b/tests/unit/core_1.bats
index 9939e3fc6..9d2413484 100644
--- a/tests/unit/core_1.bats
+++ b/tests/unit/core_1.bats
@@ -70,40 +70,43 @@ EOF
 }
 
 @test "(core) image type detection (herokuish default user)" {
-  export DOKKU_ROOT
-  deploy_app
-  source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
-  source "$PLUGIN_CORE_AVAILABLE_PATH/config/functions"
-
-  run is_image_herokuish_based "dokku/$TEST_APP" "$TEST_APP"
+  run deploy_app
   echo "output: $output"
   echo "status: $status"
   assert_success
+
+  run /bin/bash -c "dokku plugin:trigger builder-image-is-herokuish $TEST_APP dokku/$TEST_APP"
+  echo "output: $output"
+  echo "status: $status"
+  assert_output "true"
 }
 
 @test "(core) image type detection (herokuish custom user)" {
-  export DOKKU_ROOT
-  deploy_app
+  run deploy_app
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+
   CID=$(<"$DOKKU_ROOT/$TEST_APP/CONTAINER.web.1")
   docker commit --change "ENV USER postgres" "$CID" "dokku/${TEST_APP}:latest"
   dokku config:set --no-restart "$TEST_APP" DOKKU_APP_USER=postgres
   source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
   source "$PLUGIN_CORE_AVAILABLE_PATH/config/functions"
 
-  run is_image_herokuish_based "dokku/$TEST_APP" "$TEST_APP"
+  run /bin/bash -c "dokku plugin:trigger builder-image-is-herokuish $TEST_APP dokku/$TEST_APP"
   echo "output: $output"
   echo "status: $status"
-  assert_success
+  assert_output "true"
 }
 
 @test "(core) image type detection (dockerfile)" {
-  export DOKKU_ROOT
-  deploy_app dockerfile
-  source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
-  source "$PLUGIN_CORE_AVAILABLE_PATH/config/functions"
-
-  run is_image_herokuish_based "dokku/$TEST_APP" "$TEST_APP"
+  run deploy_app dockerfile
   echo "output: $output"
   echo "status: $status"
-  assert_failure
+  assert_success
+
+  run /bin/bash -c "dokku plugin:trigger builder-image-is-herokuish $TEST_APP dokku/$TEST_APP"
+  echo "output: $output"
+  echo "status: $status"
+  assert_output "false"
 }