As Dan and Heather Beliveau descend the spiral staircase of This Old House TV's Charlestown House, the sounds of the city engulf them. But the cars, horns, planes and neighborhood chatter dissipate as they reach the patio and are wrapped in the silence and solitude of a private garden. Sipping their coffee and scanning the paper they realize that the investment they made in this oasis may have been their best renovation decision. But getting to this point was hard work. (That's where I come in.) While only slightly over 500 square feet, this patio received a great deal of attention. During the renovation the house's only outside space was filled with brick, staging, fencing, cement, windows, plants and the portable toilet. But even in that condition, it had tremendous potential. First the crew and I looked at the yard's severe grading problem. The existing ground level was two and a half feet higher than the threshold of the basement storage room door. To keep soil and water from leeching under the door, we built a concrete block retaining wall. First we dug a 12-foot-deep, 18-foot-wide trench and filled it with eight inches of 3/4-inch stone, compacted. We then added four inches of "pack," 3/4-inch stone and stone dust mixed together, and compacted it until it was level with the grade we'd set for the bottom of the wall. We stacked a course of base blocks and then placed the other blocks in according to a recipe provided by the manufacturer, securing the blocks with a special adhesive. The tumbled, rough edged blocks come in four different sizes and several different colors to give the wall a natural look. When the wall was complete, we applied the capstone and backfilled behind the wall. This is the key to durability; a geotextile fabric, placed between soil and stone, acts as a weed barrier while 12 inches of 3/4-inch washed stone allow water to drain away from the wall, preventing the freezing, thawing and heaving cycle that lead to cracks. Next we moved on to the patio, where David specified a circular patio using concrete pavers made by the same manufacturer as the wall blocks. Again we dug out the work area eight-feet-deep, laid down "pack," compacted it and pour on an inch of sand. We then placed pipes around the perimeter that set that patio's height and screed away the excess sand, level to the surfacing. The pipes were removed, the holes filled with sand and we were ready to lay the pavers. When the patio was complete, we dumped a 1/2 inch of sand on top and ran a compactor over it to lock the pavers into position. The garden's walkways were made with the same pavers cast in squares and rectangles. The patio for the rental unit is concrete, but this is not your granddad's concrete. Stamped concrete is poured, colored with a dye and stamped with moulds that give the patio a texture. The process is fast and economical and doesn't allow water to penetrate the house's foundation. While I'm not usually a concrete patio person, I'm impressed with the finished product. In a small outdoor garden like this, every square inch becomes valuable. In the courtyard, we need to pack in as much greenery as possible to offset the masonry buildings that surround it. One trick is to espalier plants against fencing and walls. In this case, espaliering yews and red twig dogwood against the fence creates screening and gives us plenty of room for planting underneath them. A 15-foot locust tree will similarly soften the brick wall of a neighboring house. For color in winter, the red twig Dogwood and Golden Cyprus will shine. With amelanchier, yews, holly, rhododenron, azalea and flowering spring bulbs, the courtyard will come alive in spring.