I am learning ASP.NET and have built a basic web site that I want to use as a template for future sites. I am wondering if I should build a code generator that will take as an input an xml file which describes the application and then generate the base web site files which would look like a customized version of my template site.

Have you done this or considered it and decided against it? If you have do you think it was worth the effort?

Yes! you can if you have know-how of programming. I've used several tools like CodeSmith etc.

Actually i'm doing something like that right now. But i'm not doing web site code generator, i'm doing an form and reports code generator.

I definitely think it pays off. But it's not so simple as it look like.

If you have good templates, with well organized source code, it shouldn't be so painful :D

An advice that i can give to you about it, do take a good time to plan your database, it'll save you a lot of time in the future, and a lot of headache as well.