Before you buy on the valley edge
A walk-out lot is a ravine lot most of the time, and the conservation authority for the Oshawa area, CLOCA, holds jurisdiction over the valleys of both creeks. That means a permit from the authority, not just the City, for a deck, a pool, a shed or regrading anywhere in the regulated area, so ask for the property's mapping before you plan a backyard. Walk the slope behind the house and look for leaning trees, exposed roots and bare soil, which point to erosion. Inside, check the lower door threshold for water staining, confirm that a sump pump and a backwater valve are installed, and see how the lot drains: the ground should fall away from the foundation on the uphill side. If the walk-out level is finished, ask whether the work was permitted and whether the bedroom window meets egress. On a new Kedron or Windfields lot, ask whether the builder ever completed the rear grading. The Millers can pull the conservation mapping for any address.