diff --git a/c/build.sh b/c/build.sh
index 68c76e7..848d866 100755
--- a/c/build.sh
+++ b/c/build.sh
@@ -2,7 +2,7 @@
 set -eu
 
 cd $(dirname $0)
-BUILDDIR=build/release/$(uname)-$(uname -m)
+BUILDDIR=${BUILD_ROOT:-build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)
 cmake -DCMAKE_BUILD_TYPE=Release -B $BUILDDIR .
 cmake --build $BUILDDIR -j
 cp $BUILDDIR/rosettaboy-c ./rosettaboy-release
diff --git a/c/build_debug.sh b/c/build_debug.sh
index ba77e97..4961f98 100755
--- a/c/build_debug.sh
+++ b/c/build_debug.sh
@@ -2,7 +2,7 @@
 set -eu
 
 cd $(dirname $0)
-BUILDDIR=build/debug/$(uname)-$(uname -m)
+BUILDDIR=${BUILD_ROOT:-build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)
 cmake -DCMAKE_BUILD_TYPE=Debug -B $BUILDDIR .
 cmake --build $BUILDDIR -j
 cp $BUILDDIR/rosettaboy-c ./rosettaboy-debug
diff --git a/c/build_lto.sh b/c/build_lto.sh
index a4cb355..6114bb2 100755
--- a/c/build_lto.sh
+++ b/c/build_lto.sh
@@ -2,7 +2,7 @@
 set -eu
 
 cd $(dirname $0)
-BUILDDIR=build/lto/$(uname)-$(uname -m)
+BUILDDIR=${BUILD_ROOT:-build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)
 cmake -DCMAKE_BUILD_TYPE=Release -DENABLE_LTO=On -B $BUILDDIR .
 cmake --build $BUILDDIR -j
 cp $BUILDDIR/rosettaboy-c ./rosettaboy-lto
diff --git a/cpp/build.sh b/cpp/build.sh
index 3cdce10..7c51929 100755
--- a/cpp/build.sh
+++ b/cpp/build.sh
@@ -2,7 +2,7 @@
 set -eu
 
 cd $(dirname $0)
-BUILDDIR=build/release/$(uname)-$(uname -m)
+BUILDDIR=${BUILD_ROOT:-build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)
 cmake -DCMAKE_BUILD_TYPE=Release -B $BUILDDIR .
 cmake --build $BUILDDIR -j
 cp $BUILDDIR/rosettaboy-cpp ./rosettaboy-release
diff --git a/cpp/build_debug.sh b/cpp/build_debug.sh
index 1913f3e..9d87171 100755
--- a/cpp/build_debug.sh
+++ b/cpp/build_debug.sh
@@ -2,7 +2,7 @@
 set -eu
 
 cd $(dirname $0)
-BUILDDIR=build/debug/$(uname)-$(uname -m)
+BUILDDIR=${BUILD_ROOT:-build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)
 cmake -DCMAKE_BUILD_TYPE=Debug -B $BUILDDIR .
 cmake --build $BUILDDIR -j
 cp $BUILDDIR/rosettaboy-cpp ./rosettaboy-debug
diff --git a/cpp/build_lto.sh b/cpp/build_lto.sh
index 848aacf..f5bcfa3 100755
--- a/cpp/build_lto.sh
+++ b/cpp/build_lto.sh
@@ -2,7 +2,7 @@
 set -eu
 
 cd $(dirname $0)
-BUILDDIR=build/lto/$(uname)-$(uname -m)
+BUILDDIR=${BUILD_ROOT:-build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)
 cmake -DCMAKE_BUILD_TYPE=Release -DENABLE_LTO=On -B $BUILDDIR .
 cmake --build $BUILDDIR -j
 cp $BUILDDIR/rosettaboy-cpp ./rosettaboy-lto
diff --git a/pxd/build.sh b/pxd/build.sh
index 417bd7f..70dafa9 100755
--- a/pxd/build.sh
+++ b/pxd/build.sh
@@ -5,7 +5,7 @@ cd $(dirname $0)
 
 source py_env.sh
 
-BUILD_DIR=build
+BUILDDIR=${BUILD_ROOT:-build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)-build
 CORES=$(python3 -c 'import os; print(os.cpu_count() or 0)')
 
 if [ -t "$CORES" ]; then
@@ -15,12 +15,18 @@ else
 	echo "Found $CORES cores." 1>&2
 fi
 
-python3 setup.py build "$@" --build-base "$BUILD_DIR" --build-purelib "$BUILD_DIR" --build-lib "$BUILD_DIR" --build-scripts "$BUILD_DIR" --build-temp build_temp --parallel $CORES
+python3 setup.py build "$@" \
+	--build-base "$BUILDDIR/base" \
+	--build-purelib "$BUILDDIR/purelib" \
+	--build-lib "$BUILDDIR/lib" \
+	--build-scripts "$BUILDDIR/scripts" \
+	--build-temp "$BUILDDIR/temp" \
+	--parallel $CORES
 
 cat >rosettaboy-release <<EOD
 #!/usr/bin/env bash
 set -eu
 source "\$(dirname \$0)/py_env.sh"
-PYTHONPATH="\$(dirname \$0)/build/" exec python3 "\$(dirname \$0)/build/main.py" \$*
+PYTHONPATH="$BUILDDIR/" exec python3 "$BUILDDIR/main.py" \$*
 EOD
-chmod +x rosettaboy-release
\ No newline at end of file
+chmod +x rosettaboy-release
diff --git a/pxd/py_env.sh b/pxd/py_env.sh
index 4c23441..14a08dc 100644
--- a/pxd/py_env.sh
+++ b/pxd/py_env.sh
@@ -1,6 +1,6 @@
 # Instead of being run, this gets `source`d by `build.sh` and `format.sh`.
 
-BUILDDIR=venv/$(uname)-$(uname -m)
+BUILDDIR=${BUILD_ROOT:-build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)-venv
 PYIMPORT_EXIT=$(python3 -c 'import sdl2, black, mypy, cython' 1>&2; echo $?) # Use existing libraries (E.G. from system, or from Nix) if found.
 if [ $PYIMPORT_EXIT -eq 0 ] ; then
 	echo "Python packages found:"
diff --git a/py/py_env.sh b/py/py_env.sh
index dc82790..7dc3b45 100644
--- a/py/py_env.sh
+++ b/py/py_env.sh
@@ -1,6 +1,6 @@
 # Instead of being run, this gets `source`d by `build.sh` and `format.sh`.
 
-BUILDDIR=$(dirname $0)/venv/$(uname)-$(uname -m)
+BUILDDIR=${BUILD_ROOT:-build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)-venv
 
 # Use existing libraries (E.G. from system, or from Nix) if found.
 if python3 -c 'import sdl2, black, mypy' 2>/dev/null ; then
diff --git a/rs/build.sh b/rs/build.sh
index 9151b65..dd85520 100755
--- a/rs/build.sh
+++ b/rs/build.sh
@@ -2,5 +2,7 @@
 set -eu
 
 cd $(dirname $0)
+BUILDDIR=${BUILD_ROOT:-target}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)
+export CARGO_TARGET_DIR=$BUILDDIR
 cargo build --release
-cp ./target/release/rosettaboy-rs ./rosettaboy-release
\ No newline at end of file
+cp $BUILDDIR/release/rosettaboy-rs ./rosettaboy-release
\ No newline at end of file
diff --git a/rs/build_debug.sh b/rs/build_debug.sh
index 079aafa..cc55163 100755
--- a/rs/build_debug.sh
+++ b/rs/build_debug.sh
@@ -2,5 +2,7 @@
 set -eu
 
 cd $(dirname $0)
+BUILDDIR=${BUILD_ROOT:-target}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)
+export CARGO_TARGET_DIR=$BUILDDIR
 cargo build
-cp ./target/debug/rosettaboy-rs ./rosettaboy-debug
\ No newline at end of file
+cp $BUILDDIR/debug/rosettaboy-rs ./rosettaboy-debug
\ No newline at end of file
diff --git a/rs/build_lto.sh b/rs/build_lto.sh
index 50d2497..826484b 100755
--- a/rs/build_lto.sh
+++ b/rs/build_lto.sh
@@ -2,5 +2,7 @@
 set -eu
 
 cd $(dirname $0)
+BUILDDIR=${BUILD_ROOT:-target}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)
+export CARGO_TARGET_DIR=$BUILDDIR
 cargo build --profile release-lto
-cp ./target/release-lto/rosettaboy-rs ./rosettaboy-lto
\ No newline at end of file
+cp $BUILDDIR/release-lto/rosettaboy-rs ./rosettaboy-lto
\ No newline at end of file