diff --git a/babel.js b/babel.js
index 88817fc616c8b..1bbe4f360f180 100644
--- a/babel.js
+++ b/babel.js
@@ -1 +1 @@
-module.exports = require('./dist/server/build/babel/preset')
+module.exports = require('./dist/build/babel/preset')
diff --git a/bin/next-build b/bin/next-build
index eb60720e6ab36..7d518777565bf 100755
--- a/bin/next-build
+++ b/bin/next-build
@@ -2,7 +2,7 @@
 import { resolve, join } from 'path'
 import { existsSync } from 'fs'
 import parseArgs from 'minimist'
-import build from '../server/build'
+import build from '../build'
 import { printAndExit } from '../lib/utils'
 
 const argv = parseArgs(process.argv.slice(2), {
diff --git a/server/build/babel/plugins/handle-import.js b/build/babel/plugins/handle-import.js
similarity index 100%
rename from server/build/babel/plugins/handle-import.js
rename to build/babel/plugins/handle-import.js
diff --git a/server/build/babel/preset.js b/build/babel/preset.js
similarity index 100%
rename from server/build/babel/preset.js
rename to build/babel/preset.js
diff --git a/server/build/index.js b/build/index.js
similarity index 93%
rename from server/build/index.js
rename to build/index.js
index 809240b6aa4b3..2e0a7dd55f3c1 100644
--- a/server/build/index.js
+++ b/build/index.js
@@ -2,8 +2,8 @@ import { join } from 'path'
 import promisify from '../lib/promisify'
 import fs from 'fs'
 import webpack from 'webpack'
-import loadConfig from '../config'
-import { PHASE_PRODUCTION_BUILD, BUILD_ID_FILE } from '../../lib/constants'
+import loadConfig from '../server/config'
+import { PHASE_PRODUCTION_BUILD, BUILD_ID_FILE } from '../lib/constants'
 import getBaseWebpackConfig from './webpack'
 
 const access = promisify(fs.access)
diff --git a/server/build/loaders/emit-file-loader.js b/build/loaders/emit-file-loader.js
similarity index 100%
rename from server/build/loaders/emit-file-loader.js
rename to build/loaders/emit-file-loader.js
diff --git a/server/build/loaders/hot-self-accept-loader.js b/build/loaders/hot-self-accept-loader.js
similarity index 64%
rename from server/build/loaders/hot-self-accept-loader.js
rename to build/loaders/hot-self-accept-loader.js
index 76a658650afb0..db095819d9fac 100644
--- a/server/build/loaders/hot-self-accept-loader.js
+++ b/build/loaders/hot-self-accept-loader.js
@@ -1,11 +1,17 @@
-import { resolve, relative } from 'path'
+// @flow
+import { relative } from 'path'
 import loaderUtils from 'loader-utils'
 
-module.exports = function (content, sourceMap) {
+type Options = {|
+  extensions: RegExp,
+  include: Array<string>
+|}
+
+module.exports = function (content: string, sourceMap: any) {
   this.cacheable()
 
-  const options = loaderUtils.getOptions(this)
-  const route = getRoute(this, options)
+  const options: Options = loaderUtils.getOptions(this)
+  const route = getRoute(this.resourcePath, options)
 
   // Webpack has a built in system to prevent default from colliding, giving it a random letter per export.
   // We can safely check if Component is undefined since all other pages imported into the entrypoint don't have __webpack_exports__.default
@@ -30,18 +36,21 @@ module.exports = function (content, sourceMap) {
   `, sourceMap)
 }
 
-const nextPagesDir = resolve(__dirname, '..', '..', '..', 'pages')
-
-function getRoute (loaderContext, options) {
-  const pagesDir = resolve(loaderContext.options.context, 'pages')
-  const { resourcePath } = loaderContext
-  const dir = [pagesDir, nextPagesDir]
-    .find((d) => resourcePath.indexOf(d) === 0)
-
+function getRoute (resourcePath: string, options: Options) {
   if (!options.extensions) {
     throw new Error('extensions is not provided to hot-self-accept-loader. Please upgrade all next-plugins to the latest version.')
   }
 
+  if (!options.include) {
+    throw new Error('include option is not provided to hot-self-accept-loader. Please upgrade all next-plugins to the latest version.')
+  }
+
+  const dir = options.include.find((d) => resourcePath.indexOf(d) === 0)
+
+  if (!dir) {
+    throw new Error(`'hot-self-accept-loader' was called on a file that isn't a page.`)
+  }
+
   const path = relative(dir, resourcePath).replace(options.extensions, '.js')
   return '/' + path.replace(/((^|\/)index)?\.js$/, '')
 }
diff --git a/server/build/loaders/next-babel-loader.js b/build/loaders/next-babel-loader.js
similarity index 100%
rename from server/build/loaders/next-babel-loader.js
rename to build/loaders/next-babel-loader.js
diff --git a/server/build/plugins/build-manifest-plugin.js b/build/plugins/build-manifest-plugin.js
similarity index 95%
rename from server/build/plugins/build-manifest-plugin.js
rename to build/plugins/build-manifest-plugin.js
index be2e5fee26ff7..3336eb3d6a66f 100644
--- a/server/build/plugins/build-manifest-plugin.js
+++ b/build/plugins/build-manifest-plugin.js
@@ -1,6 +1,6 @@
 // @flow
 import { RawSource } from 'webpack-sources'
-import {BUILD_MANIFEST} from '../../../lib/constants'
+import {BUILD_MANIFEST} from '../../lib/constants'
 
 // This plugin creates a build-manifest.json for all assets that are being output
 // It has a mapping of "entry" filename to real filename. Because the real filename can be hashed in production
diff --git a/server/build/plugins/dynamic-chunks-plugin.js b/build/plugins/dynamic-chunks-plugin.js
similarity index 100%
rename from server/build/plugins/dynamic-chunks-plugin.js
rename to build/plugins/dynamic-chunks-plugin.js
diff --git a/server/build/plugins/nextjs-ssr-import.js b/build/plugins/nextjs-ssr-import.js
similarity index 100%
rename from server/build/plugins/nextjs-ssr-import.js
rename to build/plugins/nextjs-ssr-import.js
diff --git a/server/build/plugins/pages-manifest-plugin.js b/build/plugins/pages-manifest-plugin.js
similarity index 85%
rename from server/build/plugins/pages-manifest-plugin.js
rename to build/plugins/pages-manifest-plugin.js
index 8f9e265b4d063..0304f6704c52e 100644
--- a/server/build/plugins/pages-manifest-plugin.js
+++ b/build/plugins/pages-manifest-plugin.js
@@ -1,7 +1,6 @@
 // @flow
 import { RawSource } from 'webpack-sources'
-import { MATCH_ROUTE_NAME } from '../../utils'
-import {PAGES_MANIFEST} from '../../../lib/constants'
+import {PAGES_MANIFEST, ROUTE_NAME_REGEX} from '../../lib/constants'
 
 // This plugin creates a pages-manifest.json from page entrypoints.
 // This is used for mapping paths like `/` to `.next/dist/bundles/pages/index.js` when doing SSR
@@ -13,7 +12,7 @@ export default class PagesManifestPlugin {
       const pages = {}
 
       for (const entry of entries) {
-        const result = MATCH_ROUTE_NAME.exec(entry.name)
+        const result = ROUTE_NAME_REGEX.exec(entry.name)
         if (!result) {
           continue
         }
diff --git a/server/build/plugins/pages-plugin.js b/build/plugins/pages-plugin.js
similarity index 86%
rename from server/build/plugins/pages-plugin.js
rename to build/plugins/pages-plugin.js
index c838df2a3d192..f645341a9fffc 100644
--- a/server/build/plugins/pages-plugin.js
+++ b/build/plugins/pages-plugin.js
@@ -1,17 +1,17 @@
 import { ConcatSource } from 'webpack-sources'
 import {
-  IS_BUNDLED_PAGE,
-  MATCH_ROUTE_NAME
-} from '../../utils'
+  IS_BUNDLED_PAGE_REGEX,
+  ROUTE_NAME_REGEX
+} from '../../lib/constants'
 
 class PageChunkTemplatePlugin {
   apply (chunkTemplate) {
     chunkTemplate.plugin('render', function (modules, chunk) {
-      if (!IS_BUNDLED_PAGE.test(chunk.name)) {
+      if (!IS_BUNDLED_PAGE_REGEX.test(chunk.name)) {
         return modules
       }
 
-      let routeName = MATCH_ROUTE_NAME.exec(chunk.name)[1]
+      let routeName = ROUTE_NAME_REGEX.exec(chunk.name)[1]
 
       // We need to convert \ into / when we are in windows
       // to get the proper route name
diff --git a/server/build/plugins/unlink-file-plugin.js b/build/plugins/unlink-file-plugin.js
similarity index 83%
rename from server/build/plugins/unlink-file-plugin.js
rename to build/plugins/unlink-file-plugin.js
index 096bda98a8bea..475e448d5e097 100644
--- a/server/build/plugins/unlink-file-plugin.js
+++ b/build/plugins/unlink-file-plugin.js
@@ -1,7 +1,7 @@
 import { join } from 'path'
 import promisify from '../../lib/promisify'
 import fs from 'fs'
-import { IS_BUNDLED_PAGE } from '../../utils'
+import { IS_BUNDLED_PAGE_REGEX } from '../../lib/constants'
 
 const unlink = promisify(fs.unlink)
 
@@ -13,7 +13,7 @@ export default class UnlinkFilePlugin {
   apply (compiler) {
     compiler.plugin('after-emit', (compilation, callback) => {
       const removed = Object.keys(this.prevAssets)
-        .filter((a) => IS_BUNDLED_PAGE.test(a) && !compilation.assets[a])
+        .filter((a) => IS_BUNDLED_PAGE_REGEX.test(a) && !compilation.assets[a])
 
       this.prevAssets = compilation.assets
 
diff --git a/server/build/webpack.js b/build/webpack.js
similarity index 88%
rename from server/build/webpack.js
rename to build/webpack.js
index 40c34bc2a7445..5e188cea33ac2 100644
--- a/server/build/webpack.js
+++ b/build/webpack.js
@@ -12,11 +12,7 @@ import DynamicChunksPlugin from './plugins/dynamic-chunks-plugin'
 import UnlinkFilePlugin from './plugins/unlink-file-plugin'
 import PagesManifestPlugin from './plugins/pages-manifest-plugin'
 import BuildManifestPlugin from './plugins/build-manifest-plugin'
-import {SERVER_DIRECTORY} from '../../lib/constants'
-
-const nextDir = path.join(__dirname, '..', '..', '..')
-const nextNodeModulesDir = path.join(nextDir, 'node_modules')
-const nextPagesDir = path.join(nextDir, 'pages')
+import {SERVER_DIRECTORY, NEXT_PROJECT_ROOT, NEXT_PROJECT_ROOT_NODE_MODULES, NEXT_PROJECT_ROOT_DIST, DEFAULT_PAGES_DIR} from '../lib/constants'
 
 function externalsConfig (dir, isServer) {
   const externals = []
@@ -57,6 +53,15 @@ export default async function getBaseWebpackConfig (dir, {dev = false, isServer
     babel: {
       loader: 'next-babel-loader',
       options: {dev, isServer}
+    },
+    hotSelfAccept: {
+      loader: 'hot-self-accept-loader',
+      options: {
+        include: [
+          path.join(dir, 'pages')
+        ],
+        extensions: /\.(js|jsx)$/
+      }
     }
   }
 
@@ -65,13 +70,13 @@ export default async function getBaseWebpackConfig (dir, {dev = false, isServer
     .split(process.platform === 'win32' ? ';' : ':')
     .filter((p) => !!p)
 
-  const pagesEntries = await getPages(dir, {dev, isServer, pageExtensions: config.pageExtensions.join('|')})
+  const pagesEntries = await getPages(dir, {nextPagesDir: DEFAULT_PAGES_DIR, dev, isServer, pageExtensions: config.pageExtensions.join('|')})
   const totalPages = Object.keys(pagesEntries).length
   const clientEntries = !isServer ? {
     'main.js': [
-      dev && !isServer && path.join(__dirname, '..', '..', 'client', 'webpack-hot-middleware-client'),
-      dev && !isServer && path.join(__dirname, '..', '..', 'client', 'on-demand-entries-client'),
-      require.resolve(`../../client/next${dev ? '-dev' : ''}`)
+      dev && !isServer && path.join(NEXT_PROJECT_ROOT_DIST, 'client', 'webpack-hot-middleware-client'),
+      dev && !isServer && path.join(NEXT_PROJECT_ROOT_DIST, 'client', 'on-demand-entries-client'),
+      path.join(NEXT_PROJECT_ROOT_DIST, 'client', (dev ? `next-dev` : 'next'))
     ].filter(Boolean)
   } : {}
 
@@ -102,17 +107,17 @@ export default async function getBaseWebpackConfig (dir, {dev = false, isServer
     resolve: {
       extensions: ['.js', '.jsx', '.json'],
       modules: [
-        nextNodeModulesDir,
+        NEXT_PROJECT_ROOT_NODE_MODULES,
         'node_modules',
         ...nodePathList // Support for NODE_PATH environment variable
       ],
       alias: {
-        next: nextDir
+        next: NEXT_PROJECT_ROOT
       }
     },
     resolveLoader: {
       modules: [
-        nextNodeModulesDir,
+        NEXT_PROJECT_ROOT_NODE_MODULES,
         'node_modules',
         path.join(__dirname, 'loaders'),
         ...nodePathList // Support for NODE_PATH environment variable
@@ -122,14 +127,8 @@ export default async function getBaseWebpackConfig (dir, {dev = false, isServer
       rules: [
         dev && !isServer && {
           test: /\.(js|jsx)$/,
-          loader: 'hot-self-accept-loader',
-          include: [
-            path.join(dir, 'pages'),
-            nextPagesDir
-          ],
-          options: {
-            extensions: /\.(js|jsx)$/
-          }
+          include: defaultLoaders.hotSelfAccept.options.include,
+          use: defaultLoaders.hotSelfAccept
         },
         {
           test: /\.(js|jsx)$/,
@@ -206,7 +205,6 @@ export default async function getBaseWebpackConfig (dir, {dev = false, isServer
             return true
           }
 
-          // commons
           // If there are one or two pages, only move modules to common if they are
           // used in all of the pages. Otherwise, move modules used in at-least
           // 1/2 of the total pages into commons.
@@ -214,7 +212,6 @@ export default async function getBaseWebpackConfig (dir, {dev = false, isServer
             return count >= totalPages
           }
           return count >= totalPages * 0.5
-          // commons end
         }
       }),
       // We use a manifest file in development to speed up HMR
diff --git a/server/build/webpack/utils.js b/build/webpack/utils.js
similarity index 90%
rename from server/build/webpack/utils.js
rename to build/webpack/utils.js
index 960226543feea..76f752710669f 100644
--- a/server/build/webpack/utils.js
+++ b/build/webpack/utils.js
@@ -4,12 +4,10 @@ import globModule from 'glob'
 
 const glob = promisify(globModule)
 
-const nextPagesDir = path.join(__dirname, '..', '..', '..', 'pages')
-
-export async function getPages (dir, {dev, isServer, pageExtensions}) {
+export async function getPages (dir, {nextPagesDir, dev, isServer, pageExtensions}) {
   const pageFiles = await getPagePaths(dir, {dev, isServer, pageExtensions})
 
-  return getPageEntries(pageFiles, {isServer, pageExtensions})
+  return getPageEntries(pageFiles, {nextPagesDir, isServer, pageExtensions})
 }
 
 export async function getPagePaths (dir, {dev, isServer, pageExtensions}) {
@@ -50,7 +48,7 @@ export function createEntry (filePath, {name, pageExtensions} = {}) {
 }
 
 // Convert page paths into entries
-export function getPageEntries (pagePaths, {isServer = false, pageExtensions} = {}) {
+export function getPageEntries (pagePaths, {nextPagesDir, isServer = false, pageExtensions} = {}) {
   const entries = {}
 
   for (const filePath of pagePaths) {
diff --git a/flow-typed/npm/loader-utils_vx.x.x.js b/flow-typed/npm/loader-utils_vx.x.x.js
new file mode 100644
index 0000000000000..617e83d2db327
--- /dev/null
+++ b/flow-typed/npm/loader-utils_vx.x.x.js
@@ -0,0 +1,102 @@
+// flow-typed signature: fbec9bc08efb50bade7bd6c2bab84e41
+// flow-typed version: <<STUB>>/loader-utils_v1.1.0/flow_v0.73.0
+
+/**
+ * This is an autogenerated libdef stub for:
+ *
+ *   'loader-utils'
+ *
+ * Fill this stub out by replacing all the `any` types.
+ *
+ * Once filled out, we encourage you to share your work with the
+ * community by sending a pull request to:
+ * https://github.com/flowtype/flow-typed
+ */
+
+declare module 'loader-utils' {
+  declare module.exports: any;
+}
+
+/**
+ * We include stubs for each file inside this npm package in case you need to
+ * require those files directly. Feel free to delete any files that aren't
+ * needed.
+ */
+declare module 'loader-utils/lib/getCurrentRequest' {
+  declare module.exports: any;
+}
+
+declare module 'loader-utils/lib/getHashDigest' {
+  declare module.exports: any;
+}
+
+declare module 'loader-utils/lib/getOptions' {
+  declare module.exports: any;
+}
+
+declare module 'loader-utils/lib/getRemainingRequest' {
+  declare module.exports: any;
+}
+
+declare module 'loader-utils/lib/index' {
+  declare module.exports: any;
+}
+
+declare module 'loader-utils/lib/interpolateName' {
+  declare module.exports: any;
+}
+
+declare module 'loader-utils/lib/isUrlRequest' {
+  declare module.exports: any;
+}
+
+declare module 'loader-utils/lib/parseQuery' {
+  declare module.exports: any;
+}
+
+declare module 'loader-utils/lib/parseString' {
+  declare module.exports: any;
+}
+
+declare module 'loader-utils/lib/stringifyRequest' {
+  declare module.exports: any;
+}
+
+declare module 'loader-utils/lib/urlToRequest' {
+  declare module.exports: any;
+}
+
+// Filename aliases
+declare module 'loader-utils/lib/getCurrentRequest.js' {
+  declare module.exports: $Exports<'loader-utils/lib/getCurrentRequest'>;
+}
+declare module 'loader-utils/lib/getHashDigest.js' {
+  declare module.exports: $Exports<'loader-utils/lib/getHashDigest'>;
+}
+declare module 'loader-utils/lib/getOptions.js' {
+  declare module.exports: $Exports<'loader-utils/lib/getOptions'>;
+}
+declare module 'loader-utils/lib/getRemainingRequest.js' {
+  declare module.exports: $Exports<'loader-utils/lib/getRemainingRequest'>;
+}
+declare module 'loader-utils/lib/index.js' {
+  declare module.exports: $Exports<'loader-utils/lib/index'>;
+}
+declare module 'loader-utils/lib/interpolateName.js' {
+  declare module.exports: $Exports<'loader-utils/lib/interpolateName'>;
+}
+declare module 'loader-utils/lib/isUrlRequest.js' {
+  declare module.exports: $Exports<'loader-utils/lib/isUrlRequest'>;
+}
+declare module 'loader-utils/lib/parseQuery.js' {
+  declare module.exports: $Exports<'loader-utils/lib/parseQuery'>;
+}
+declare module 'loader-utils/lib/parseString.js' {
+  declare module.exports: $Exports<'loader-utils/lib/parseString'>;
+}
+declare module 'loader-utils/lib/stringifyRequest.js' {
+  declare module.exports: $Exports<'loader-utils/lib/stringifyRequest'>;
+}
+declare module 'loader-utils/lib/urlToRequest.js' {
+  declare module.exports: $Exports<'loader-utils/lib/urlToRequest'>;
+}
diff --git a/lib/constants.js b/lib/constants.js
index 6888a5f2b5186..cd73adc2f9d5e 100644
--- a/lib/constants.js
+++ b/lib/constants.js
@@ -1,3 +1,4 @@
+import {join} from 'path'
 export const PHASE_EXPORT = 'phase-export'
 export const PHASE_PRODUCTION_BUILD = 'phase-production-build'
 export const PHASE_PRODUCTION_SERVER = 'phase-production-server'
@@ -12,3 +13,9 @@ export const BLOCKED_PAGES = [
   '/_app',
   '/_error'
 ]
+export const IS_BUNDLED_PAGE_REGEX = /^bundles[/\\]pages.*\.js$/
+export const ROUTE_NAME_REGEX = /^bundles[/\\]pages[/\\](.*)\.js$/
+export const NEXT_PROJECT_ROOT = join(__dirname, '..', '..')
+export const NEXT_PROJECT_ROOT_DIST = join(NEXT_PROJECT_ROOT, 'dist')
+export const NEXT_PROJECT_ROOT_NODE_MODULES = join(NEXT_PROJECT_ROOT, 'node_modules')
+export const DEFAULT_PAGES_DIR = join(NEXT_PROJECT_ROOT_DIST, 'pages')
diff --git a/server/lib/promisify.js b/lib/promisify.js
similarity index 100%
rename from server/lib/promisify.js
rename to lib/promisify.js
diff --git a/package.json b/package.json
index 25187785f4f7b..1964a04a89e99 100644
--- a/package.json
+++ b/package.json
@@ -38,7 +38,7 @@
     "test": "cross-env npm run testall || npm run testall",
     "coveralls": "nyc --instrument=false --source-map=false report --temp-directory=./coverage --reporter=text-lcov | coveralls",
     "flow": "flow check",
-    "lint": "standard 'bin/*' 'client/**/*.js' 'examples/**/*.js' 'lib/**/*.js' 'pages/**/*.js' 'server/**/*.js' 'test/**/*.js'",
+    "lint": "standard 'bin/*' 'client/**/*.js' 'examples/**/*.js' 'lib/**/*.js' 'pages/**/*.js' 'server/**/*.js' 'build/**/*.js' 'test/**/*.js'",
     "prepublish": "npm run release",
     "precommit": "lint-staged"
   },
diff --git a/readme.md b/readme.md
index 0bd4aa2b5f9b5..17e72c2b59144 100644
--- a/readme.md
+++ b/readme.md
@@ -1235,54 +1235,82 @@ module.exports = {
   <ul><li><a href="./examples/with-webpack-bundle-analyzer">Custom webpack bundle analyzer</a></li></ul>
 </details></p>
 
+Some commonly asked for features are available as modules:
+
+- [@zeit/next-css](https://github.com/zeit/next-plugins/tree/master/packages/next-css)
+- [@zeit/next-sass](https://github.com/zeit/next-plugins/tree/master/packages/next-sass)
+- [@zeit/next-less](https://github.com/zeit/next-plugins/tree/master/packages/next-less)
+- [@zeit/next-preact](https://github.com/zeit/next-plugins/tree/master/packages/next-preact)
+- [@zeit/next-typescript](https://github.com/zeit/next-plugins/tree/master/packages/next-typescript)
+
+*Warning: The `webpack` function is executed twice, once for the server and once for the client. This allows you to distinguish between client and server configuration using the `isServer` property*
+
+Multiple configurations can be combined together with function composition. For example:
+
+```js
+const withTypescript = require('@zeit/next-typescript')
+const withSass = require('@zeit/next-sass')
+
+module.exports = withTypescript(withSass({
+  webpack(config, options) {
+    // Further custom configuration here
+    return config
+  }
+}))
+```
+
 In order to extend our usage of `webpack`, you can define a function that extends its config via `next.config.js`.
 
 ```js
-// This file is not going through babel transformation.
-// So, we write it in vanilla JS
-// (But you could use ES2015 features supported by your Node.js version)
+// next.config.js is not transformed by Babel. So you can only use javascript features supported by your version of Node.js.
 
 module.exports = {
   webpack: (config, { buildId, dev, isServer, defaultLoaders }) => {
     // Perform customizations to webpack config
-
     // Important: return the modified config
     return config
   },
   webpackDevMiddleware: config => {
     // Perform customizations to webpack dev middleware config
-
     // Important: return the modified config
     return config
   }
 }
 ```
 
-Some commonly asked for features are available as modules:
+The second argument to `webpack` is an object containing properties useful when customing the WebPack configuration:
 
-- [@zeit/next-css](https://github.com/zeit/next-plugins/tree/master/packages/next-css)
-- [@zeit/next-sass](https://github.com/zeit/next-plugins/tree/master/packages/next-sass)
-- [@zeit/next-less](https://github.com/zeit/next-plugins/tree/master/packages/next-less)
-- [@zeit/next-preact](https://github.com/zeit/next-plugins/tree/master/packages/next-preact)
-- [@zeit/next-typescript](https://github.com/zeit/next-plugins/tree/master/packages/next-typescript)
-
-*Warning: The `webpack` function is executed twice, once for the server and once for the client. This allows you to distinguish between client and server configuration using the `isServer` property*
+- `buildId` - `String` the build id used as a unique identifier between builds
+- `dev` - `Boolean` shows if the compilation is done in development mode
+- `isServer` - `Boolean` shows if the resulting configuration will be used for server side (`true`), or client size compilation (`false`).
+- `defaultLoaders` - `Object` Holds loader objects Next.js uses internally, so that you can use them in custom configuration
+  - `babel` - `Object` the `babel-loader` configuration for Next.js.
+  - `hotSelfAccept` - `Object` the `hot-self-accept-loader` configuration. This loader should only be used for advanced use cases. For example [`@zeit/next-typescript`](https://github.com/zeit/next-plugins/tree/master/packages/next-typescript) adds it for top-level typescript pages.
 
-Multiple configurations can be combined together with function composition. For example:
+Example usage of `defaultLoaders.babel`: 
 
 ```js
-const withTypescript = require('@zeit/next-typescript')
-const withSass = require('@zeit/next-sass')
+// Example next.config.js for adding a loader that depends on babel-loader
+// This source was taken from the @zeit/next-mdx plugin source: 
+// https://github.com/zeit/next-plugins/blob/master/packages/next-mdx
+module.exports = {
+  webpack: (config, {}) => {
+    config.module.rules.push({
+      test: /\.mdx/,
+      use: [
+        options.defaultLoaders.babel,
+        {
+          loader: '@mdx-js/loader',
+          options: pluginOptions.options
+        }
+      ]
+    })
 
-module.exports = withTypescript(withSass({
-  webpack(config, options) {
-    // Further custom configuration here
     return config
   }
-}))
+}
 ```
 
-
 ### Customizing babel config
 
 <p><details>
diff --git a/server/hot-reloader.js b/server/hot-reloader.js
index 4fb1b0fb88663..44a4869c16671 100644
--- a/server/hot-reloader.js
+++ b/server/hot-reloader.js
@@ -4,12 +4,12 @@ import WebpackHotMiddleware from 'webpack-hot-middleware'
 import del from 'del'
 import onDemandEntryHandler from './on-demand-entry-handler'
 import webpack from 'webpack'
-import getBaseWebpackConfig from './build/webpack'
+import getBaseWebpackConfig from '../build/webpack'
 import UUID from 'uuid'
 import {
-  IS_BUNDLED_PAGE,
   addCorsSupport
 } from './utils'
+import {IS_BUNDLED_PAGE_REGEX} from '../lib/constants'
 
 export default class HotReloader {
   constructor (dir, { quiet, config } = {}) {
@@ -145,7 +145,7 @@ export default class HotReloader {
       const chunkNames = new Set(
         compilation.chunks
           .map((c) => c.name)
-          .filter(name => IS_BUNDLED_PAGE.test(name))
+          .filter(name => IS_BUNDLED_PAGE_REGEX.test(name))
       )
 
       const failedChunkNames = new Set(compilation.errors
@@ -157,7 +157,7 @@ export default class HotReloader {
 
       const chunkHashes = new Map(
         compilation.chunks
-          .filter(c => IS_BUNDLED_PAGE.test(c.name))
+          .filter(c => IS_BUNDLED_PAGE_REGEX.test(c.name))
           .map((c) => [c.name, c.hash])
       )
 
diff --git a/server/index.js b/server/index.js
index cc52dc7d64657..3f362b8bbae66 100644
--- a/server/index.js
+++ b/server/index.js
@@ -4,7 +4,7 @@ import { parse as parseUrl } from 'url'
 import { parse as parseQs } from 'querystring'
 import fs from 'fs'
 import http, { STATUS_CODES } from 'http'
-import promisify from './lib/promisify'
+import promisify from '../lib/promisify'
 import {
   renderToHTML,
   renderErrorToHTML,
diff --git a/server/lib/source-map-support.js b/server/lib/source-map-support.js
index fdd6c466719a4..1d0bb9120bee8 100644
--- a/server/lib/source-map-support.js
+++ b/server/lib/source-map-support.js
@@ -28,7 +28,7 @@ async function rewriteTraceLine (trace: string): Promise<string> {
 
   // Load these on demand.
   const fs = require('fs')
-  const promisify = require('./promisify')
+  const promisify = require('../../lib/promisify')
 
   const readFile = promisify(fs.readFile)
   const access = promisify(fs.access)
diff --git a/server/on-demand-entry-handler.js b/server/on-demand-entry-handler.js
index 66e83a3bb97ab..0ca994c752dda 100644
--- a/server/on-demand-entry-handler.js
+++ b/server/on-demand-entry-handler.js
@@ -3,11 +3,11 @@ import { EventEmitter } from 'events'
 import { join } from 'path'
 import { parse } from 'url'
 import touch from 'touch'
-import promisify from './lib/promisify'
+import promisify from '../lib/promisify'
 import globModule from 'glob'
 import {normalizePagePath, pageNotFoundError} from './require'
-import {createEntry} from './build/webpack/utils'
-import { MATCH_ROUTE_NAME, IS_BUNDLED_PAGE } from './utils'
+import {createEntry} from '../build/webpack/utils'
+import { ROUTE_NAME_REGEX, IS_BUNDLED_PAGE_REGEX } from '../lib/constants'
 
 const ADDED = Symbol('added')
 const BUILDING = Symbol('building')
@@ -63,7 +63,7 @@ export default function onDemandEntryHandler (devMiddleware, compilers, {
           if (!hasNoModuleFoundError) return false
 
           // The page itself is missing. So this is a failed page.
-          if (IS_BUNDLED_PAGE.test(e.module.name)) return true
+          if (IS_BUNDLED_PAGE_REGEX.test(e.module.name)) return true
 
           // No dependencies means this is a top level page.
           // So this is a failed page.
@@ -72,7 +72,7 @@ export default function onDemandEntryHandler (devMiddleware, compilers, {
         .map(e => e.module.chunks)
         .reduce((a, b) => [...a, ...b], [])
         .map(c => {
-          const pageName = MATCH_ROUTE_NAME.exec(c.name)[1]
+          const pageName = ROUTE_NAME_REGEX.exec(c.name)[1]
           return normalizePage(`/${pageName}`)
         })
 
diff --git a/server/utils.js b/server/utils.js
index d66ddd1602ff2..4b6339c65c630 100644
--- a/server/utils.js
+++ b/server/utils.js
@@ -1,9 +1,6 @@
 import { join } from 'path'
 import { readdirSync, existsSync } from 'fs'
 
-export const IS_BUNDLED_PAGE = /^bundles[/\\]pages.*\.js$/
-export const MATCH_ROUTE_NAME = /^bundles[/\\]pages[/\\](.*)\.js$/
-
 export function getChunkNameFromFilename (filename, dev) {
   if (dev) {
     return filename.replace(/.[^.]*$/, '')
diff --git a/taskfile.js b/taskfile.js
index 577a0fcd3d2e8..0edd131d77738 100644
--- a/taskfile.js
+++ b/taskfile.js
@@ -5,7 +5,7 @@ const mkdirp = require('mkdirp')
 const isWindows = /^win/.test(process.platform)
 
 export async function compile (task) {
-  await task.parallel(['bin', 'server', 'lib', 'client'])
+  await task.parallel(['bin', 'server', 'nextbuild', 'lib', 'client'])
 }
 
 export async function bin (task, opts) {
@@ -23,6 +23,11 @@ export async function server (task, opts) {
   notify('Compiled server files')
 }
 
+export async function nextbuild (task, opts) {
+  await task.source(opts.src || 'build/**/*.js').babel().target('dist/build')
+  notify('Compiled build files')
+}
+
 export async function client (task, opts) {
   await task.source(opts.src || 'client/**/*.js').babel().target('dist/client')
   notify('Compiled client files')
@@ -50,6 +55,7 @@ export default async function (task) {
   await task.watch('bin/*', 'bin')
   await task.watch('pages/**/*.js', 'copy')
   await task.watch('server/**/*.js', 'server')
+  await task.watch('build/**/*.js', 'nextbuild')
   await task.watch('client/**/*.js', 'client')
   await task.watch('lib/**/*.js', 'lib')
 }
diff --git a/test/isolated/webpack-utils.test.js b/test/isolated/webpack-utils.test.js
index f73de78d8ec88..e206061ad20b2 100644
--- a/test/isolated/webpack-utils.test.js
+++ b/test/isolated/webpack-utils.test.js
@@ -1,7 +1,7 @@
 /* global describe, it, expect */
 
-import {normalize} from 'path'
-import {getPageEntries, createEntry} from '../../dist/server/build/webpack/utils'
+import {normalize, join} from 'path'
+import {getPageEntries, createEntry} from '../../dist/build/webpack/utils'
 
 describe('createEntry', () => {
   it('Should turn a path into a page entry', () => {
@@ -48,33 +48,35 @@ describe('createEntry', () => {
 })
 
 describe('getPageEntries', () => {
+  const nextPagesDir = join(__dirname, '..', '..', 'dist', 'pages')
+
   it('Should return paths', () => {
     const pagePaths = ['pages/index.js']
-    const pageEntries = getPageEntries(pagePaths)
+    const pageEntries = getPageEntries(pagePaths, {nextPagesDir})
     expect(pageEntries[normalize('bundles/pages/index.js')][0]).toBe('./pages/index.js')
   })
 
   it('Should include default _error', () => {
     const pagePaths = ['pages/index.js']
-    const pageEntries = getPageEntries(pagePaths)
+    const pageEntries = getPageEntries(pagePaths, {nextPagesDir})
     expect(pageEntries[normalize('bundles/pages/_error.js')][0]).toMatch(/dist[/\\]pages[/\\]_error\.js/)
   })
 
   it('Should not include default _error when _error.js is inside the pages directory', () => {
     const pagePaths = ['pages/index.js', 'pages/_error.js']
-    const pageEntries = getPageEntries(pagePaths)
+    const pageEntries = getPageEntries(pagePaths, {nextPagesDir})
     expect(pageEntries[normalize('bundles/pages/_error.js')][0]).toBe('./pages/_error.js')
   })
 
   it('Should include default _document when isServer is true', () => {
     const pagePaths = ['pages/index.js']
-    const pageEntries = getPageEntries(pagePaths, {isServer: true})
+    const pageEntries = getPageEntries(pagePaths, {nextPagesDir, isServer: true})
     expect(pageEntries[normalize('bundles/pages/_document.js')][0]).toMatch(/dist[/\\]pages[/\\]_document\.js/)
   })
 
   it('Should not include default _document when _document.js is inside the pages directory', () => {
     const pagePaths = ['pages/index.js', 'pages/_document.js']
-    const pageEntries = getPageEntries(pagePaths, {isServer: true})
+    const pageEntries = getPageEntries(pagePaths, {nextPagesDir, isServer: true})
     expect(pageEntries[normalize('bundles/pages/_document.js')][0]).toBe('./pages/_document.js')
   })
 })
diff --git a/test/lib/next-test-utils.js b/test/lib/next-test-utils.js
index 174b55b5e99fc..d2c54d461de04 100644
--- a/test/lib/next-test-utils.js
+++ b/test/lib/next-test-utils.js
@@ -9,7 +9,7 @@ import { readFileSync, writeFileSync, existsSync, unlinkSync } from 'fs'
 import fkill from 'fkill'
 
 import server from '../../dist/server/next'
-import build from '../../dist/server/build'
+import build from '../../dist/build'
 import _export from '../../dist/server/export'
 import _pkg from '../../package.json'
 
diff --git a/test/unit/handle-import-babel-plugin.test.js b/test/unit/handle-import-babel-plugin.test.js
index 48fb8a58b177a..543b27b6543ad 100644
--- a/test/unit/handle-import-babel-plugin.test.js
+++ b/test/unit/handle-import-babel-plugin.test.js
@@ -1,5 +1,5 @@
 /* global describe, it, expect */
-import { getModulePath } from '../../dist/server/build/babel/plugins/handle-import'
+import { getModulePath } from '../../dist/build/babel/plugins/handle-import'
 
 function cleanPath (mPath) {
   return mPath