diff --git a/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/index-html-webpack-plugin.ts b/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/index-html-webpack-plugin.ts
index a8805ef8f068..be4c1497cd73 100644
--- a/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/index-html-webpack-plugin.ts
+++ b/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/index-html-webpack-plugin.ts
@@ -7,7 +7,7 @@
  */
 import { createHash } from 'crypto';
 import { Compiler, compilation } from 'webpack';
-import { RawSource } from 'webpack-sources';
+import { RawSource, ReplaceSource } from 'webpack-sources';
 
 const parse5 = require('parse5');
 
@@ -95,71 +95,94 @@ export class IndexHtmlWebpackPlugin {
 
       // Find the head and body elements
       const treeAdapter = parse5.treeAdapters.default;
-      const document = parse5.parse(inputContent, { treeAdapter });
+      const document = parse5.parse(inputContent, { treeAdapter, locationInfo: true });
       let headElement;
       let bodyElement;
-      for (const topNode of document.childNodes) {
-        if (topNode.tagName === 'html') {
-          for (const htmlNode of topNode.childNodes) {
-            if (htmlNode.tagName === 'head') {
-              headElement = htmlNode;
+      for (const docChild of document.childNodes) {
+        if (docChild.tagName === 'html') {
+          for (const htmlChild of docChild.childNodes) {
+            if (htmlChild.tagName === 'head') {
+              headElement = htmlChild;
             }
-            if (htmlNode.tagName === 'body') {
-              bodyElement = htmlNode;
+            if (htmlChild.tagName === 'body') {
+              bodyElement = htmlChild;
             }
           }
         }
       }
 
-      // Inject into the html
-
       if (!headElement || !bodyElement) {
         throw new Error('Missing head and/or body elements');
       }
 
+      // Determine script insertion point
+      let scriptInsertionPoint;
+      if (bodyElement.__location && bodyElement.__location.endTag) {
+        scriptInsertionPoint = bodyElement.__location.endTag.startOffset;
+      } else {
+        // Less accurate fallback
+        // parse5 4.x does not provide locations if malformed html is present
+        scriptInsertionPoint = inputContent.indexOf('</body>');
+      }
+
+      let styleInsertionPoint;
+      if (headElement.__location && headElement.__location.endTag) {
+        styleInsertionPoint = headElement.__location.endTag.startOffset;
+      } else {
+        // Less accurate fallback
+        // parse5 4.x does not provide locations if malformed html is present
+        styleInsertionPoint = inputContent.indexOf('</head>');
+      }
+
+      // Inject into the html
+      const indexSource = new ReplaceSource(new RawSource(inputContent), this._options.input);
+
+      const scriptElements = treeAdapter.createDocumentFragment();
       for (const script of scripts) {
         const attrs = [
           { name: 'type', value: 'text/javascript' },
           { name: 'src', value: (this._options.deployUrl || '') + script },
         ];
+
         if (this._options.sri) {
-          const algo = 'sha384';
-          const hash = createHash(algo)
-            .update(compilation.assets[script].source(), 'utf8')
-            .digest('base64');
-          attrs.push(
-            { name: 'integrity', value: `${algo}-${hash}` },
-            { name: 'crossorigin', value: 'anonymous' },
-          );
+          const content = compilation.assets[script].source();
+          attrs.push(...this._generateSriAttributes(content));
         }
 
-        const element = treeAdapter.createElement(
-          'script',
-          undefined,
-          attrs,
-        );
-        treeAdapter.appendChild(bodyElement, element);
+        const element = treeAdapter.createElement('script', undefined, attrs);
+        treeAdapter.appendChild(scriptElements, element);
       }
 
+      indexSource.insert(
+        scriptInsertionPoint,
+        parse5.serialize(scriptElements, { treeAdapter }),
+      );
+
       // Adjust base href if specified
-      if (this._options.baseHref != undefined) {
+      if (typeof this._options.baseHref == 'string') {
         let baseElement;
-        for (const node of headElement.childNodes) {
-          if (node.tagName === 'base') {
-            baseElement = node;
-            break;
+        for (const headChild of headElement.childNodes) {
+          if (headChild.tagName === 'base') {
+            baseElement = headChild;
           }
         }
 
+        const baseFragment = treeAdapter.createDocumentFragment();
+
         if (!baseElement) {
-          const element = treeAdapter.createElement(
+          baseElement = treeAdapter.createElement(
             'base',
             undefined,
             [
               { name: 'href', value: this._options.baseHref },
             ],
           );
-          treeAdapter.appendChild(headElement, element);
+
+          treeAdapter.appendChild(baseFragment, baseElement);
+          indexSource.insert(
+            headElement.__location.startTag.endOffset + 1,
+            parse5.serialize(baseFragment, { treeAdapter }),
+          );
         } else {
           let hrefAttribute;
           for (const attribute of baseElement.attrs) {
@@ -172,24 +195,51 @@ export class IndexHtmlWebpackPlugin {
           } else {
             baseElement.attrs.push({ name: 'href', value: this._options.baseHref });
           }
+
+          treeAdapter.appendChild(baseFragment, baseElement);
+          indexSource.replace(
+            baseElement.__location.startOffset,
+            baseElement.__location.endOffset,
+            parse5.serialize(baseFragment, { treeAdapter }),
+          );
         }
       }
 
+      const styleElements = treeAdapter.createDocumentFragment();
       for (const stylesheet of stylesheets) {
-        const element = treeAdapter.createElement(
-          'link',
-          undefined,
-          [
-            { name: 'rel', value: 'stylesheet' },
-            { name: 'href', value: (this._options.deployUrl || '') + stylesheet },
-          ],
-        );
-        treeAdapter.appendChild(headElement, element);
+        const attrs = [
+          { name: 'rel', value: 'stylesheet' },
+          { name: 'href', value: (this._options.deployUrl || '') + stylesheet },
+        ];
+
+        if (this._options.sri) {
+          const content = compilation.assets[stylesheet].source();
+          attrs.push(...this._generateSriAttributes(content));
+        }
+
+        const element = treeAdapter.createElement('link', undefined, attrs);
+        treeAdapter.appendChild(styleElements, element);
       }
 
+      indexSource.insert(
+        styleInsertionPoint,
+        parse5.serialize(styleElements, { treeAdapter }),
+      );
+
       // Add to compilation assets
-      const outputContent = parse5.serialize(document, { treeAdapter });
-      compilation.assets[this._options.output] = new RawSource(outputContent);
+      compilation.assets[this._options.output] = indexSource;
     });
   }
+
+  private _generateSriAttributes(content: string) {
+    const algo = 'sha384';
+    const hash = createHash(algo)
+      .update(content, 'utf8')
+      .digest('base64');
+
+    return [
+      { name: 'integrity', value: `${algo}-${hash}` },
+      { name: 'crossorigin', value: 'anonymous' },
+    ];
+  }
 }
diff --git a/packages/angular_devkit/build_angular/test/browser/index-bom_spec_large.ts b/packages/angular_devkit/build_angular/test/browser/index_spec_large.ts
similarity index 54%
rename from packages/angular_devkit/build_angular/test/browser/index-bom_spec_large.ts
rename to packages/angular_devkit/build_angular/test/browser/index_spec_large.ts
index 6164ce1c1596..78377fb53303 100644
--- a/packages/angular_devkit/build_angular/test/browser/index-bom_spec_large.ts
+++ b/packages/angular_devkit/build_angular/test/browser/index_spec_large.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import { join, normalize, virtualFs } from '@angular-devkit/core';
+import { join, normalize, tags, virtualFs } from '@angular-devkit/core';
 import { tap } from 'rxjs/operators';
 import { Timeout, browserTargetSpec, host, runTargetSpec } from '../utils';
 
@@ -52,4 +52,42 @@ describe('Browser Builder works with BOM index.html', () => {
       }),
     ).subscribe(undefined, done.fail, done);
   }, Timeout.Basic);
+
+  it('keeps escaped charaters', (done) => {
+    host.writeMultipleFiles({
+      'src/index.html': tags.oneLine`
+        <html><head><title>&iacute;</title><base href="/"></head>
+        <body><app-root></app-root></body></html>
+      `,
+    });
+
+    runTargetSpec(host, browserTargetSpec).pipe(
+      tap((buildEvent) => expect(buildEvent.success).toBe(true)),
+      tap(() => {
+        const fileName = join(outputPath, 'index.html');
+        const content = virtualFs.fileBufferToString(host.scopedSync().read(normalize(fileName)));
+        // tslint:disable-next-line:max-line-length
+        expect(content).toBe(`<html><head><title>&iacute;</title><base href="/"></head> <body><app-root></app-root><script type="text/javascript" src="runtime.js"></script><script type="text/javascript" src="polyfills.js"></script><script type="text/javascript" src="styles.js"></script><script type="text/javascript" src="vendor.js"></script><script type="text/javascript" src="main.js"></script></body></html>`);
+      }),
+    ).subscribe(undefined, done.fail, done);
+  }, Timeout.Basic);
+
+  it('keeps custom template charaters', (done) => {
+    host.writeMultipleFiles({
+      'src/index.html': tags.oneLine`
+        <html><head><base href="/"><%= csrf_meta_tags %></head>
+        <body><app-root></app-root></body></html>
+      `,
+    });
+
+    runTargetSpec(host, browserTargetSpec).pipe(
+      tap((buildEvent) => expect(buildEvent.success).toBe(true)),
+      tap(() => {
+        const fileName = join(outputPath, 'index.html');
+        const content = virtualFs.fileBufferToString(host.scopedSync().read(normalize(fileName)));
+        // tslint:disable-next-line:max-line-length
+        expect(content).toBe(`<html><head><base href="/"><%= csrf_meta_tags %></head> <body><app-root></app-root><script type="text/javascript" src="runtime.js"></script><script type="text/javascript" src="polyfills.js"></script><script type="text/javascript" src="styles.js"></script><script type="text/javascript" src="vendor.js"></script><script type="text/javascript" src="main.js"></script></body></html>`);
+      }),
+    ).subscribe(undefined, done.fail, done);
+  }, Timeout.Basic);
 });
diff --git a/packages/angular_devkit/build_angular/test/browser/service-worker_spec_large.ts b/packages/angular_devkit/build_angular/test/browser/service-worker_spec_large.ts
index 081faac7ee39..a14764cdd5ba 100644
--- a/packages/angular_devkit/build_angular/test/browser/service-worker_spec_large.ts
+++ b/packages/angular_devkit/build_angular/test/browser/service-worker_spec_large.ts
@@ -98,7 +98,7 @@ describe('Browser Builder', () => {
           hashTable: {
             '/favicon.ico': '84161b857f5c547e3699ddfbffc6d8d737542e01',
             '/assets/folder-asset.txt': '617f202968a6a81050aa617c2e28e1dca11ce8d4',
-            '/index.html': '3e659d6e536916b7d178d02a2e6e5492f868bf68',
+            '/index.html': '843c96f0aeadc8f093b1b2203c08891ecd8f7425',
           },
         });
       }),
@@ -153,7 +153,7 @@ describe('Browser Builder', () => {
           hashTable: {
             '/foo/bar/favicon.ico': '84161b857f5c547e3699ddfbffc6d8d737542e01',
             '/foo/bar/assets/folder-asset.txt': '617f202968a6a81050aa617c2e28e1dca11ce8d4',
-            '/foo/bar/index.html': '5b53fa9e07e4111b8ef84613fb989a56fee502b0',
+            '/foo/bar/index.html': '9ef50361678004b3b197c12cbc74962e5a15b844',
           },
         });
       }),