diff --git a/sdbuild/packages/python_packages_focal/post.sh b/sdbuild/packages/python_packages_focal/post.sh
new file mode 100644
index 0000000000..df9f1e70cf
--- /dev/null
+++ b/sdbuild/packages/python_packages_focal/post.sh
@@ -0,0 +1,11 @@
+#!/bin/bash
+
+set -x
+set -e
+
+target=$1
+target_dir=root/.cache/pip
+script_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+sudo mkdir -p $script_dir/pre-built/$target_dir
+sudo cp -rf $target/$target_dir/wheels $script_dir/pre-built/$target_dir
diff --git a/sdbuild/packages/python_packages_focal/pre-built/README.md b/sdbuild/packages/python_packages_focal/pre-built/README.md
new file mode 100644
index 0000000000..34b22296b5
--- /dev/null
+++ b/sdbuild/packages/python_packages_focal/pre-built/README.md
@@ -0,0 +1,3 @@
+folder gets populated with wheels built from Python source inside a chroot (e.g. numpy for armhf)
+
+See pre.sh and post.sh in the package folder to see how files are copied to/from the sdcard image
diff --git a/sdbuild/packages/python_packages_focal/pre.sh b/sdbuild/packages/python_packages_focal/pre.sh
new file mode 100644
index 0000000000..7cd6c15cbb
--- /dev/null
+++ b/sdbuild/packages/python_packages_focal/pre.sh
@@ -0,0 +1,11 @@
+#!/bin/bash
+
+set -x
+set -e
+
+target=$1
+target_dir=root/.cache/pip
+script_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+sudo mkdir -p $target/$target_dir
+sudo cp -rf $script_dir/pre-built/$target_dir/* $target/$target_dir