Expert: Ted Barnhill (Principal, Design45 LLC) - 8/1/2008

Question
I am in the process of building a new home and would like to know if it is possible to build a bathroom above a garage.  My concern is that the pipes would freeze over winter.  I live in Winnipeg and our winter temperatures go down to -30C.  Is there a way to insulate the pipes so there is no chance of freezing pipes?

Answer
Susan,

Yes, adding finished spaces over garages is increasingly common in modern construction, including bathrooms.  In cold climates, the plumbing will need to be in a heated chase.  Normally this can be accommodated without undue trouble or expense.

However, some healthy building experts will recommend against this type of construction, and cars bring many toxic chemicals into the home.  Detached garages are best from a chemical separation point of view, followed by attached garages with a well sealed wall and door, with no air exchange between spaces.  If you build living spaces over the garage, you must be sure that you have a good builder who can provide an impermeable air barrier that will perform well indefinitely.  This is a tall order, and while possible, requires abnormally good detailing.

Good luck building your new home.  If you have any follow up questions feel free to post them.  -Ted