Report Builder is a pre-built application for use in building reports for the SQL Server Reporting Service. It is not a tool for adding into a custom ASP.NET application.
http://msdn2.microsoft.com/en-us/library/ms159862.aspx
You can use the ReportViewer control to include Reporting Service reports in a custom ASP.NET application.
http://msdn2.microsoft.com/en-us/library/ms159862.aspx
Dean Fiala
Very Practical Software, Inc.