Patty O'Stone

Dear Joe,                            

I have a patio at the back of my home made of two foot patio stones.  Do I need a permit if I want to expand on it?  I would like to make it larger.  Thank you for your help,

Scott B.

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Scott,

Thank you for the great question.  It’s not often I am presented a question like this.  This can help identify some of the finer points of the city planning rules.  Though, a situation like yours is something that many DIYers take for granted.  Most would never think to inquire as to the requirements of the city planning department.

But I am very glad you asked.   The Ontario Building Code regulates how buildings and accessory structures are constructed.   A patio by its very nature is not a structure and so is not regulated by the Building Code.  Any building or hard landscaping, (ie. Retaining walls) over 18 inches qualifies as a structure under the OBC and so must conform to the rules, such as the 32 inch setback from property lines.  So that answers part of your question. 

Now, the zoning department will have more to say about your situation than the building inspector will.  When we endeavour to develop our property, as we are entitled to do, we have to keep in mind why the rules are there.  Precipitation, primarily in the form of rain is a large part of what the zoning department works to control.  They design the streets and the sewers but also inform us as to how much of the area of our property can be paved, roofed or otherwise covered so as to prevent the rain from hitting the ground and being absorbed into the earth.  The more bare earth you have in your city, the more rainwater and meltwater can be absorbed into the ground, thus not being handled by the cities’ waste water system.  More paving equals more rainwater being channelled to the storm sewer and not being absorbed by the ground. 

 Aesthetics is another concern.   If we were allowed to pave our entire yards we would in short order end up with a city that looked like downtown New York or some mad max, post-apocalyptic wasteland with nary a living plant in sight.  So the city planners are also concerned about that.  So, that being said, here are the guidelines from the mouth of the city planner:  40% of main street frontage can be paved or hard landscaped (patio stones, interlocking brick, flagstone, etc.), 60% if you live in a townhouse or rowhouse.  Back yards and side yards not facing a main street can be covered up to 100% if you so choose with the one caveat being this:  Though you will have no contest from the city planners, you may have a lawsuit on your hands if your completely paved back yard is graded so that all the rainwater is washing out your neighbours prize winning rose beds.