My son, Zach, and I were looking for a summer project to build. It was a toss up between a kayak and a miniature golf course. Zach said we'd use a golf course a lot more than a kayak, so we decided to build a ten hole miniature golf course. We designed the course so it would not take up a lot of room and would use as many materials that we had on hand. The basic design is two 4' by 8' courses connected together by a child's metal slide as a causeway with a third 4' by 8' course lower, (we live on a hill). The ball rolls from the upper levels to the lower one by 2 inch pvc pipes from holes on the two higher courses. We built obstacles that can be moved from hole to hole. We built our courses on three extra in ground swimming pool panels that were leftover when we installed our pool.
You could just as easily frame up the courses with 2 x 4s and plywood as the deck subfloor. I'll detail the construction in the following steps.
Step 1: Materials
Purchase or scrounge the material.
2x4s Pressure treated (unless you have 3 swimming pools panels laying around)
4x4s Pressure Treated
3 4 foot by 8 foot 1/2 plywood
Metal Kid's slide
4 inch diameter PVC pipe
2 inch diameter PVC if you want to have a course lower to putt down too
3/4 inch plywood
We had quite a few things laying around the house. The biggest expense was the indoor/outdoor carpet. We spent about $150 U.S. dollars in 2010 to build this.