Luckily, the main water supply enters the house just a few feet behind the back wall of the garage. So, locating the softener and filters on the opposite side of that wall at the rear of the garage meant that a simple copper loop is all the was necessary to send the treated water back into the main house supply. The only additional mod to the existing copper lines outside was to tee off for the hose bib that would have to go when I cut into the original main line.