The Personal Builder: pbuilder
Using pbuilder as a package builder allows you to build the package from within a chroot environment. You can build binary packages without using pbuilder, but you must have all the build dependencies installed on your system first. However, pbuilder allows the packager to check the build dependencies because the package is built within a minimal Ubuntu installation, and the build dependencies are downloaded according to the debian/control file.
PbuilderHowto is a comprehensive guide to almost anything you could wish to do with pbuilder.
A short overview:
To create a pbuilder environment, run
$ sudo pbuilder create --distribution $(lsb_release -cs) --othermirror "deb http://archive.ubuntu.com/ubuntu $(lsb_release -cs) main restricted universe multiverse"
To build a package using pbuilder, run
$ sudo pbuilder build *.dsc
To update a pbuilder environment, run
$ sudo pbuilder update
use pbuilder-dist (of the ubuntu-dev-tools) to have several different pbuilder setups for different Ubuntu releases.