diff --git a/dev-infra/release/BUILD.bazel b/dev-infra/release/BUILD.bazel
index 24e5c87c45..8b9af3d913 100644
--- a/dev-infra/release/BUILD.bazel
+++ b/dev-infra/release/BUILD.bazel
@@ -8,6 +8,7 @@ ts_library(
     module_name = "@angular/dev-infra-private/release",
     visibility = ["//dev-infra:__subpackages__"],
     deps = [
+        "//dev-infra/release/build",
         "//dev-infra/utils",
         "@npm//@types/yargs",
         "@npm//yargs",
diff --git a/dev-infra/release/build/BUILD.bazel b/dev-infra/release/build/BUILD.bazel
new file mode 100644
index 0000000000..dfd353d3a8
--- /dev/null
+++ b/dev-infra/release/build/BUILD.bazel
@@ -0,0 +1,38 @@
+load("@npm_bazel_typescript//:index.bzl", "ts_library")
+load("//tools:defaults.bzl", "jasmine_node_test")
+
+ts_library(
+    name = "build",
+    srcs = glob(
+        [
+            "**/*.ts",
+        ],
+        exclude = ["*.spec.ts"],
+    ),
+    module_name = "@angular/dev-infra-private/release/build",
+    visibility = ["//dev-infra:__subpackages__"],
+    deps = [
+        "//dev-infra/release/config",
+        "//dev-infra/utils",
+        "@npm//@types/node",
+        "@npm//@types/yargs",
+    ],
+)
+
+ts_library(
+    name = "test_lib",
+    srcs = glob([
+        "*.spec.ts",
+    ]),
+    deps = [
+        ":build",
+        "//dev-infra/release/config",
+        "@npm//@types/jasmine",
+        "@npm//@types/node",
+    ],
+)
+
+jasmine_node_test(
+    name = "test",
+    deps = [":test_lib"],
+)
diff --git a/dev-infra/release/build/build-worker.ts b/dev-infra/release/build/build-worker.ts
new file mode 100644
index 0000000000..5cc090495e
--- /dev/null
+++ b/dev-infra/release/build/build-worker.ts
@@ -0,0 +1,32 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+/*
+ * This file will be spawned as a separate process when the `ng-dev release build` command is
+ * invoked. A separate process allows us to hide any superfluous stdout output from arbitrary
+ * build commands that we cannot control. This is necessary as the `ng-dev release build` command
+ * supports stdout JSON output that should be parsable and not polluted from other stdout messages.
+ */
+
+import {getReleaseConfig} from '../config/index';
+
+// Start the release package building.
+main();
+
+/** Main function for building the release packages. */
+async function main() {
+  if (process.send === undefined) {
+    throw Error('This script needs to be invoked as a NodeJS worker.');
+  }
+
+  const config = getReleaseConfig();
+  const builtPackages = await config.buildPackages();
+
+  // Transfer the built packages back to the parent process.
+  process.send(builtPackages);
+}
diff --git a/dev-infra/release/build/build.spec.ts b/dev-infra/release/build/build.spec.ts
new file mode 100644
index 0000000000..ac4df6938c
--- /dev/null
+++ b/dev-infra/release/build/build.spec.ts
@@ -0,0 +1,77 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import * as releaseConfig from '../config/index';
+import {ReleaseBuildCommandModule} from './cli';
+import * as index from './index';
+
+describe('ng-dev release build', () => {
+  let npmPackages: string[];
+  let buildPackages: jasmine.Spy;
+
+  beforeEach(() => {
+    npmPackages = ['@angular/pkg1', '@angular/pkg2'];
+    buildPackages = jasmine.createSpy('buildPackages').and.resolveTo([
+      {name: '@angular/pkg1', outputPath: 'dist/pkg1'},
+      {name: '@angular/pkg2', outputPath: 'dist/pkg2'},
+    ]);
+
+    // We cannot test the worker process, so we fake the worker function and
+    // directly call the package build function.
+    spyOn(index, 'buildReleaseOutput').and.callFake(() => buildPackages());
+    // We need to stub out the `process.exit` function during tests as the CLI
+    // handler calls those in case of failures.
+    spyOn(process, 'exit');
+  });
+
+  /** Invokes the build command handler. */
+  async function invokeBuild({json}: {json?: boolean} = {}) {
+    spyOn(releaseConfig, 'getReleaseConfig')
+        .and.returnValue({npmPackages, buildPackages, generateReleaseNotesForHead: async () => {}});
+    await ReleaseBuildCommandModule.handler({json: !!json, $0: '', _: []});
+  }
+
+  it('should invoke configured build packages function', async () => {
+    await invokeBuild();
+    expect(buildPackages).toHaveBeenCalledTimes(1);
+    expect(process.exit).toHaveBeenCalledTimes(0);
+  });
+
+  it('should print built packages as JSON if `--json` is specified', async () => {
+    const writeSpy = spyOn(process.stdout, 'write');
+    await invokeBuild({json: true});
+
+    expect(buildPackages).toHaveBeenCalledTimes(1);
+    expect(writeSpy).toHaveBeenCalledTimes(1);
+
+    const jsonText = writeSpy.calls.mostRecent().args[0] as string;
+    const parsed = JSON.parse(jsonText);
+
+    expect(parsed).toEqual([
+      {name: '@angular/pkg1', outputPath: 'dist/pkg1'},
+      {name: '@angular/pkg2', outputPath: 'dist/pkg2'}
+    ]);
+    expect(process.exit).toHaveBeenCalledTimes(0);
+  });
+
+  it('should error if package has not been built', async () => {
+    // Set up a NPM package that is not built.
+    npmPackages.push('@angular/non-existent');
+
+    spyOn(console, 'error');
+    await invokeBuild();
+
+    expect(console.error).toHaveBeenCalledTimes(2);
+    expect(console.error)
+        .toHaveBeenCalledWith(
+            jasmine.stringMatching(`Release output missing for the following packages`));
+    expect(console.error).toHaveBeenCalledWith(jasmine.stringMatching(`- @angular/non-existent`));
+    expect(process.exit).toHaveBeenCalledTimes(1);
+    expect(process.exit).toHaveBeenCalledWith(1);
+  });
+});
diff --git a/dev-infra/release/build/cli.ts b/dev-infra/release/build/cli.ts
new file mode 100644
index 0000000000..9898e5f74b
--- /dev/null
+++ b/dev-infra/release/build/cli.ts
@@ -0,0 +1,75 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {Arguments, Argv, CommandModule} from 'yargs';
+
+import {getConfig} from '../../utils/config';
+import {error, green, info, red, warn, yellow} from '../../utils/console';
+import {BuiltPackage, getReleaseConfig} from '../config/index';
+
+import {buildReleaseOutput} from './index';
+
+/** Command line options for building a release. */
+export interface ReleaseBuildOptions {
+  json: boolean;
+}
+
+/** Yargs command builder for configuring the `ng-dev release build` command. */
+function builder(argv: Argv): Argv<ReleaseBuildOptions> {
+  return argv.option('json', {
+    type: 'boolean',
+    description: 'Whether the built packages should be printed to stdout as JSON.',
+    default: false,
+  });
+}
+
+/** Yargs command handler for building a release. */
+async function handler(args: Arguments<ReleaseBuildOptions>) {
+  const {npmPackages} = getReleaseConfig();
+  let builtPackages = await buildReleaseOutput();
+
+  // If package building failed, print an error and exit with an error code.
+  if (builtPackages === null) {
+    error(red(`  ✘   Could not build release output. Please check output above.`));
+    process.exit(1);
+  }
+
+  // If no packages have been built, we assume that this is never correct
+  // and exit with an error code.
+  if (builtPackages.length === 0) {
+    error(red(`  ✘   No release packages have been built. Please ensure that the`));
+    error(red(`      build script is configured correctly in ".ng-dev".`));
+    process.exit(1);
+  }
+
+  const missingPackages =
+      npmPackages.filter(pkgName => !builtPackages!.find(b => b.name === pkgName));
+
+  // Check for configured release packages which have not been built. We want to
+  // error and exit if any configured package has not been built.
+  if (missingPackages.length > 0) {
+    error(red(`  ✘   Release output missing for the following packages:`));
+    missingPackages.forEach(pkgName => error(red(`      - ${pkgName}`)));
+    process.exit(1);
+  }
+
+  if (args.json) {
+    process.stdout.write(JSON.stringify(builtPackages, null, 2));
+  } else {
+    info(green('  ✓   Built release packages.'));
+    builtPackages.forEach(({name}) => info(green(`      - ${name}`)));
+  }
+}
+
+/** CLI command module for building release output. */
+export const ReleaseBuildCommandModule: CommandModule<{}, ReleaseBuildOptions> = {
+  builder,
+  handler,
+  command: 'build',
+  describe: 'Builds the release output for the current branch.',
+};
diff --git a/dev-infra/release/build/index.ts b/dev-infra/release/build/index.ts
new file mode 100644
index 0000000000..7a024490a4
--- /dev/null
+++ b/dev-infra/release/build/index.ts
@@ -0,0 +1,36 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {fork} from 'child_process';
+import {BuiltPackage} from '../config/index';
+
+/**
+ * Builds the release output without polluting the process stdout. Build scripts commonly
+ * print messages to stderr or stdout. This is fine in most cases, but sometimes other tooling
+ * reserves stdout for data transfer (e.g. when `ng release build --json` is invoked). To not
+ * pollute the stdout in such cases, we launch a child process for building the release packages
+ * and redirect all stdout output to the stderr channel (which can be read in the terminal).
+ */
+export async function buildReleaseOutput(): Promise<BuiltPackage[]|null> {
+  return new Promise(resolve => {
+    const buildProcess = fork(require.resolve('./build-worker'), [], {
+      // The stdio option is set to redirect any "stdout" output directly to the "stderr" file
+      // descriptor. An additional "ipc" file descriptor is created to support communication with
+      // the build process. https://nodejs.org/api/child_process.html#child_process_options_stdio.
+      stdio: ['inherit', 2, 2, 'ipc'],
+    });
+    let builtPackages: BuiltPackage[]|null = null;
+
+    // The child process will pass the `buildPackages()` output through the
+    // IPC channel. We keep track of it so that we can use it as resolve value.
+    buildProcess.on('message', buildResponse => builtPackages = buildResponse);
+
+    // On child process exit, resolve the promise with the received output.
+    buildProcess.on('exit', () => resolve(builtPackages));
+  });
+}
diff --git a/dev-infra/release/cli.ts b/dev-infra/release/cli.ts
index cc568af79a..ab3da00573 100644
--- a/dev-infra/release/cli.ts
+++ b/dev-infra/release/cli.ts
@@ -7,6 +7,7 @@
  */
 import * as yargs from 'yargs';
 
+import {ReleaseBuildCommandModule} from './build/cli';
 import {buildEnvStamp} from './stamping/env-stamp';
 
 /** Build the parser for the release commands. */
@@ -14,6 +15,7 @@ export function buildReleaseParser(localYargs: yargs.Argv) {
   return localYargs.help()
       .strict()
       .demandCommand()
+      .command(ReleaseBuildCommandModule)
       .command(
           'build-env-stamp', 'Build the environment stamping information', {},
           () => buildEnvStamp());