Schroot

sudo apt-get install debootstrap 
sudo apt-get install schroot
sudo nano /etc/schroot/chroot.d/precise_x85_64.conf
 
 
[precise_x86_64]
description=Ubuntu 12.04 Precise for i386
type=directory
location=/srv/chroot/precise_x86_64
#personality=linux64
root-users=bob
users=bob,john,joe
 
mkdir -p /srv/chroot/precise_x86_64
debootstrap --variant=buildd --arch=amd64 precise /srv/chroot/precise_x86_64/ http://archive.ubuntu.com/ubuntu/
 
schroot -c precise_x86_64 -u bob