diff --git a/packages/angular/build/src/builders/application/tests/options/assets_spec.ts b/packages/angular/build/src/builders/application/tests/options/assets_spec.ts
index 96ae3c0d943e..573711afe3b2 100644
--- a/packages/angular/build/src/builders/application/tests/options/assets_spec.ts
+++ b/packages/angular/build/src/builders/application/tests/options/assets_spec.ts
@@ -107,19 +107,19 @@ describeBuilder(buildApplication, APPLICATION_BUILDER_INFO, (harness) => {
         harness.expectFile('dist/browser/test.svg').toNotExist();
       });
 
-      it('fail if asset path is not within project source root', async () => {
-        await harness.writeFile('test.svg', '<svg></svg>');
+      it('copies an asset from project root (outside source root)', async () => {
+        await harness.writeFile('extra.txt', 'extra');
 
         harness.useTarget('build', {
           ...BASE_OPTIONS,
-          assets: ['test.svg'],
+          assets: ['extra.txt'],
         });
 
-        const { error } = await harness.executeOnce({ outputLogsOnException: false });
+        const { result } = await harness.executeOnce();
 
-        expect(error?.message).toMatch('path must start with the project source root');
+        expect(result?.success).toBe(true);
 
-        harness.expectFile('dist/browser/test.svg').toNotExist();
+        harness.expectFile('dist/browser/extra.txt').content.toBe('extra');
       });
     });
 
@@ -359,6 +359,17 @@ describeBuilder(buildApplication, APPLICATION_BUILDER_INFO, (harness) => {
         harness.expectFile('dist/browser/subdirectory/test.svg').content.toBe('<svg></svg>');
       });
 
+      it('fails if asset path is outside workspace root', async () => {
+        harness.useTarget('build', {
+          ...BASE_OPTIONS,
+          assets: ['../outside.txt'],
+        });
+
+        const { error } = await harness.executeOnce({ outputLogsOnException: false });
+
+        expect(error?.message).toMatch('asset path must be within the workspace root');
+      });
+
       it('fails if output option is not within project output path', async () => {
         await harness.writeFile('test.svg', '<svg></svg>');
 
diff --git a/packages/angular/build/src/utils/normalize-asset-patterns.ts b/packages/angular/build/src/utils/normalize-asset-patterns.ts
index 8a8b2c2cbf1f..929e88fff506 100644
--- a/packages/angular/build/src/utils/normalize-asset-patterns.ts
+++ b/packages/angular/build/src/utils/normalize-asset-patterns.ts
@@ -11,12 +11,6 @@ import { statSync } from 'node:fs';
 import * as path from 'node:path';
 import { AssetPattern, AssetPatternClass } from '../builders/application/schema';
 
-export class MissingAssetSourceRootException extends Error {
-  constructor(path: string) {
-    super(`The ${path} asset path must start with the project source root.`);
-  }
-}
-
 export function normalizeAssetPatterns(
   assetPatterns: AssetPattern[],
   workspaceRoot: string,
@@ -30,16 +24,24 @@ export function normalizeAssetPatterns(
   // When sourceRoot is not available, we default to ${projectRoot}/src.
   const sourceRoot = projectSourceRoot || path.join(projectRoot, 'src');
   const resolvedSourceRoot = path.resolve(workspaceRoot, sourceRoot);
+  const resolvedProjectRoot = path.resolve(workspaceRoot, projectRoot);
 
   return assetPatterns.map((assetPattern) => {
     // Normalize string asset patterns to objects.
     if (typeof assetPattern === 'string') {
       const assetPath = path.normalize(assetPattern);
       const resolvedAssetPath = path.resolve(workspaceRoot, assetPath);
+      let root: string;
 
       // Check if the string asset is within sourceRoot.
-      if (!resolvedAssetPath.startsWith(resolvedSourceRoot)) {
-        throw new MissingAssetSourceRootException(assetPattern);
+      if (resolvedAssetPath.startsWith(resolvedSourceRoot)) {
+        root = resolvedSourceRoot;
+      } else if (resolvedAssetPath.startsWith(resolvedProjectRoot)) {
+        root = resolvedProjectRoot;
+      } else if (resolvedAssetPath.startsWith(workspaceRoot)) {
+        root = workspaceRoot;
+      } else {
+        throw new Error(`The ${assetPattern} asset path must be within the workspace root.`);
       }
 
       let glob: string, input: string;
@@ -63,8 +65,8 @@ export function normalizeAssetPatterns(
         input = path.dirname(assetPath);
       }
 
-      // Output directory for both is the relative path from source root to input.
-      const output = path.relative(resolvedSourceRoot, path.resolve(workspaceRoot, input));
+      // Output directory for both is the relative path from the root to input.
+      const output = path.relative(root, path.resolve(workspaceRoot, input));
 
       assetPattern = { glob, input, output };
     } else {
diff --git a/packages/angular_devkit/build_angular/src/builders/browser-esbuild/tests/options/assets_spec.ts b/packages/angular_devkit/build_angular/src/builders/browser-esbuild/tests/options/assets_spec.ts
index 740612d19478..1493b55172a8 100644
--- a/packages/angular_devkit/build_angular/src/builders/browser-esbuild/tests/options/assets_spec.ts
+++ b/packages/angular_devkit/build_angular/src/builders/browser-esbuild/tests/options/assets_spec.ts
@@ -106,21 +106,6 @@ describeBuilder(buildEsbuildBrowser, BROWSER_BUILDER_INFO, (harness) => {
 
         harness.expectFile('dist/test.svg').toNotExist();
       });
-
-      it('fail if asset path is not within project source root', async () => {
-        await harness.writeFile('test.svg', '<svg></svg>');
-
-        harness.useTarget('build', {
-          ...BASE_OPTIONS,
-          assets: ['test.svg'],
-        });
-
-        const { error } = await harness.executeOnce({ outputLogsOnException: false });
-
-        expect(error?.message).toMatch('path must start with the project source root');
-
-        harness.expectFile('dist/test.svg').toNotExist();
-      });
     });
 
     describe('longhand syntax', () => {