diff --git a/e2e/tsconfig.json b/e2e/tsconfig.json
index a4130cff60a6..53ea134f0699 100644
--- a/e2e/tsconfig.json
+++ b/e2e/tsconfig.json
@@ -1,3 +1,5 @@
+// TypeScript config that is used to build the e2e spec files. Protractor will use TS-Node to
+// compile the e2e/ folder at runtime.
 {
   "compilerOptions": {
     "declaration": true,
diff --git a/src/demo-app/tsconfig-aot.json b/src/demo-app/tsconfig-aot.json
index c2ad1d498dc4..eadf8e0b2520 100644
--- a/src/demo-app/tsconfig-aot.json
+++ b/src/demo-app/tsconfig-aot.json
@@ -1,6 +1,8 @@
-/* Config file for the Angular Compiler. Paths need to be relative to the dist folder. */
+// TypeScript config that extends the demo-app tsconfig file. This config compiles the 
+// "main-aot.ts" file and also enables templage code generation / AOT. All paths need
+// to be relative to the output directory.
 {
-  "extends": "./tsconfig",
+  "extends": "./tsconfig-build",
   "compilerOptions": {
     "experimentalDecorators": true,
     "paths": {
diff --git a/src/demo-app/tsconfig.json b/src/demo-app/tsconfig-build.json
similarity index 82%
rename from src/demo-app/tsconfig.json
rename to src/demo-app/tsconfig-build.json
index 7b70b0212017..224f8b102c13 100644
--- a/src/demo-app/tsconfig.json
+++ b/src/demo-app/tsconfig-build.json
@@ -1,3 +1,5 @@
+// TypeScript config file that is used to compile the demo-app. Target environment will be ES5,
+// since the demo-app will be served in the browser.
 {
   "compilerOptions": {
     "declaration": false,
diff --git a/src/e2e-app/tsconfig.json b/src/e2e-app/tsconfig-build.json
similarity index 79%
rename from src/e2e-app/tsconfig.json
rename to src/e2e-app/tsconfig-build.json
index 637f489bd75e..b640a7213c83 100644
--- a/src/e2e-app/tsconfig.json
+++ b/src/e2e-app/tsconfig-build.json
@@ -1,3 +1,5 @@
+// TypeScript config file that is used to compile the e2e-app. Protractor will run all specs
+// against the e2e-app in the browser and therefore the code needs to be ES5 compatible.
 {
   "compilerOptions": {
     "declaration": true,
diff --git a/src/lib/tsconfig.json b/src/lib/tsconfig-build.json
similarity index 80%
rename from src/lib/tsconfig.json
rename to src/lib/tsconfig-build.json
index 67ebfc7d9f85..4819e3972621 100644
--- a/src/lib/tsconfig.json
+++ b/src/lib/tsconfig-build.json
@@ -1,3 +1,5 @@
+// TypeScript config file that is used to compile the library. Target environment needs to be
+// ES2015 since the build process will create FESM bundles using rollup.
 {
   "compilerOptions": {
     "baseUrl": ".",
diff --git a/src/lib/tsconfig-specs.json b/src/lib/tsconfig-specs.json
index c0bfeb60ea43..c84a07778eaf 100644
--- a/src/lib/tsconfig-specs.json
+++ b/src/lib/tsconfig-specs.json
@@ -1,5 +1,8 @@
+// TypeScript config file that extends the default tsconfig file for the library. This config is 
+// used to compile the specs for Karma. Since the code will run inside of the browser, the target
+// needs to be ES5. The format needs to be CommonJS since Karma only supports that module format.
 {
-  "extends": "./tsconfig",
+  "extends": "./tsconfig-build",
   "compilerOptions": {
     "module": "commonjs",
     "target": "es5",
diff --git a/src/tsconfig.json b/src/tsconfig.json
new file mode 100644
index 000000000000..9f199f2cf4a7
--- /dev/null
+++ b/src/tsconfig.json
@@ -0,0 +1,15 @@
+// TypeScript config file that matches all source files in the project. This file is read by 
+// IDEs and ensures that `experimentalDecorator` warnings are not showing up.
+{
+  "compilerOptions": {
+    "experimentalDecorators": true,
+    "module": "es2015",
+    "moduleResolution": "node",
+    "outDir": "../../dist/packages/all",
+    "sourceMap": true,
+    "inlineSources": true,
+    "target": "es2015",
+    "lib": ["es2015", "dom"],
+    "types": ["jasmine"]
+  }
+}
diff --git a/tools/gulp/tasks/development.ts b/tools/gulp/tasks/development.ts
index fc4636f1a6f1..316905617bfc 100644
--- a/tools/gulp/tasks/development.ts
+++ b/tools/gulp/tasks/development.ts
@@ -16,7 +16,7 @@ task(':watch:devapp', () => {
 });
 
 /** Path to the demo-app tsconfig file. */
-const tsconfigPath = join(appDir, 'tsconfig.json');
+const tsconfigPath = join(appDir, 'tsconfig-build.json');
 
 task(':build:devapp:ts', tsBuildTask(tsconfigPath));
 task(':build:devapp:scss', sassBuildTask(outDir, appDir));
diff --git a/tools/gulp/tasks/e2e.ts b/tools/gulp/tasks/e2e.ts
index f84859244dd2..ea94fad90712 100644
--- a/tools/gulp/tasks/e2e.ts
+++ b/tools/gulp/tasks/e2e.ts
@@ -13,7 +13,7 @@ const appDir = path.join(SOURCE_ROOT, 'e2e-app');
 const outDir = DIST_E2EAPP;
 
 const PROTRACTOR_CONFIG_PATH = path.join(PROJECT_ROOT, 'test/protractor.conf.js');
-const tsconfigPath = path.join(appDir, 'tsconfig.json');
+const tsconfigPath = path.join(appDir, 'tsconfig-build.json');
 
 task(':watch:e2eapp', () => {
   watch(path.join(appDir, '**/*.ts'), [':build:e2eapp:ts']);
diff --git a/tools/gulp/tasks/library.ts b/tools/gulp/tasks/library.ts
index 2de4da5c29d4..e46f8d4d9e53 100644
--- a/tools/gulp/tasks/library.ts
+++ b/tools/gulp/tasks/library.ts
@@ -13,7 +13,7 @@ const inlineResources = require('../../../scripts/release/inline-resources');
 const uglify = require('uglify-js');
 
 const libraryRoot = join(SOURCE_ROOT, 'lib');
-const tsconfigPath = join(libraryRoot, 'tsconfig.json');
+const tsconfigPath = join(libraryRoot, 'tsconfig-build.json');
 
 // Paths to the different output directories.
 const materialDir = DIST_MATERIAL;
diff --git a/tools/gulp/tsconfig.json b/tools/gulp/tsconfig.json
index 50414a019e52..ab9b9a6c6023 100644
--- a/tools/gulp/tsconfig.json
+++ b/tools/gulp/tsconfig.json
@@ -1,3 +1,5 @@
+// TypeScript config file that will be used to compile the gulp tasks. The normal gulpfile will
+// use TS-Node to compile the gulp tasks at runtime.
 {
   "compilerOptions": {
     "experimentalDecorators": true,