During your structural appointment with your design consultant ask them, they usually know either by that appointment or a little bit after it (i.e. in your second one).
You can also call George (city of Milton 905-878-7252 ask for George in the Engineering & Development plannig department I think) and see if he has the street layout that has your home on it. It would give you an early idea if the city and/or builder has yours as a reverse image. But it's not a guarantee though because that street layout can sometimes change due to a builder/mattamy request later on.
Best to get your design consultant to confirm if yours is a reverse or not.
Read the below 2 topics, they talk about this subject.
http://www.hawthornevillager.com/phpbb/viewtopic.php?p=680&highlight=#680
http://www.hawthornevillager.com/phpbb/viewtopic.php?p=43&highlight=#43