Building base source

[Baho Utot]

I am experimenting with building the base source.

What do I need to set (which knobs) to be able to build the base source 
and have the binaries built into a home directory.

The source will be in /usr/src but I want all the binaries and all other 
files produced by the build to goto in /usr/home/FreeBSD/base/target.

Will it be a copy of want is installed in the / (root) filesystem?

Thanks