We have just purchased a newer home and we want to put a patio in the back yard. The backyard is presently grass, our back yard also has a slope, under the back window where we want to start the patio it is 18 inches from the ground to the start of the brick, at the other end where we want to end the patio, it is 32 inches from the ground to the brick. Which means we have to build up the one end 14 inches to make the patio level. We would like to do a cement patio or flagstone, with a retaining wall about 2 feet high around the cement, just to give a nice edge for people to sit on. NOW our questions. Can we put up the retaining blocks then fill in and build up area that needs to be raised by just putting pebbles and fill in the area on top of the grass that is there or do we have to dig out the entire area and then build it up. What is the best way to go about this..