diff --git a/README b/README
index e1a8432..d52a388 100755
--- a/README
+++ b/README
@@ -3,4 +3,10 @@ EnvayaSMS is an Android app that acts as a SMS and MMS gateway.
 For more information and installation instructions, 
 see http://sms.envaya.org/
 
+This project uses ant (or NetBeans) as the build tool.
+Before building, first create a local.properties file in the project root directory,
+and set sdk.dir to the path of your android sdk, e.g.:
+
+sdk.dir=C:\\android-sdk
+
 The code is released under the MIT license; see LICENSE
\ No newline at end of file