Ground That Falls Across a Rural Lot
A lot that falls across open farmland gives you a deck that is level with the back door at one end and a long way off the ground at the other. That is normal, and it is also where the code thresholds start to bite. Past 600 mm above adjacent grade an attached deck needs a City of Ottawa building permit. Past 1.8 m above the finished ground the 900 mm guard relaxation falls away and 1,070 mm applies. Both can apply on the same deck on a sloping lot, at the low corner, while the high corner is barely a step off the lawn. Drainage is the other half of it. Water crossing a yard on its way to a ditch or a field drain will find the space under a deck and stay there if nothing lets it out, so grading around the low side and keeping the frame clear of wet ground both go into the design.

