The PlanShould I tell you how many times I have seen patios that are too small? I did not think you would be interested. Chances are you have seen the same thing. A patio with just enough room to fit a table and chairs or a cramped patio with a grill sitting off in the grass. The sad thing is that small, ineffective patios can be avoided with just a little bit of planning.
Use Your Existing Rooms
If you are thinking of building a patio, start your planning by walking into your living, dining or family room. Do those rooms currently seat the number of people that you plan to seat on the patio? Is there enough room between existing pieces of furniture in these rooms? If so, you are off to a good start. I hate to spend time reinventing the wheel!
Tape Measure and Graph Paper
A simple plan is better than no plan. You can make a simple plan by using standard 1/4 inch graph paper. This paper usually has light blue lines that are spaced at 1/4 inch intervals both horizontally and vertically on a piece of paper. Art supply stores sometimes carry this paper in large sheets (11 x 17 inches). The pre-drawn lines allow you to draw the plan more easily to scale. Make a quick drawing of what you think you want. Use a scale of 1/4 inch on paper equaling one real foot in your back yard.
Assuming you have chosen a patio size similar to one of the existing rooms in your house, measure the size of the room using your tape measure. Translate those measurements to the paper. You should remember to keep the drawing in scale. In addition, don't forget to add two to three feet behind furniture! This is a common mistake. Surely you do not want your patio furniture right at the edge of the brick!
Checking the Drawing for Fun & Function
Now we must check to see if the plan will work. Measure the size of your patio furniture or what you intend to buy. Make scale cut outs of these objects and color them. For example, most common chairs measure about two feet wide and deep. So, cut out a piece of paper that is 1/2 inch on each side. Do this for all the furniture. Place the colored cut outs on the patio plan. Do they fit? Is there plenty of space between the colored pieces of paper to walk? Are the pieces at the edge of the patio boundary? You say everything is fine? GREAT! I knew you could do it. Frank Lloyd Wright would be proud, that's for sure!
Source: http://www.askthebuilder.com/B409_Patio_Sizing_Tips.shtml