If your site is level or just slightly sloped, it might be a great idea to build an on-grade deck. Whether attached to the house or freestanding, on-grade decks are relatively easy to design and construct. They can be sized and shaped in countless ways. Because they rest fairly close to the ground, they seldom require railings or steps. On-grade decks are especially appropriate additions to single-story homes or to those with a low profile where a raised or multilevel deck might look out of place or overwhelm the existing structure.
Some on-grade decks are designed to sit flush with the ground, but their direct contact with the earth calls for materials that are impervious to decay, such as pressure-treated lumber or a non-wood product such as PVC (polyvinyl chloride) vinyl. Most designs are elevated slightly above the surface of the ground, however, to compensate for uneven or sloping ground and to allow for proper drainage and air circulation.