Terrace steps have aesthetic and ecological benefits for sloped landscapes. On hills that are extremely sloped, terraces make it possible to plant gardens, by levelling out sections of land to give the hill a stepped appearance. Terraces also help prevent erosion. During heavy rains, water runs down hillsides, eroding the soil. By building terraced steps on that same hillside, the rainwater soaks into the soil on the steps instead of running downhill. Treated wood is the most common terrace building material since it is relatively inexpensive when compared to masonry and is easy to install.
Check the building codes for your city concerning terraces and walls. As with the construction of all outdoor structures, you need to follow all local building codes. Contact the utilities commission to find out if there are any utility lines buried where you want to build the steps.
Measure the run and rise of the hill. The rise is the height of the hill and the run is its length. The greater the run and rise of the hill, the more terraces that are needed in order to keep the structure level.
Dig the trench for your bottom tier. The exact depth of the trench is dependent upon the size of the individual steps and the type of materials that will be used to build the steps. Dig the trench only slightly wider than the building material. When using masonry products, follow all manufacturer instructions. Firmly pack the bottom of the trench before placing the building materials inside.
Dig a trench into the hillside that is level with the bottom of the first trench for the sides of the terrace. Stop digging when the depth of the trench is one inch greater than the thickness of your building materials.
Layer the bottom of the trench with your building materials. Drill holes through any lumber and hammer in 18-inch spikes to secure them. Continue layering the lumber, overlapping the corners and joints. Spike each layer together.
Move the soil from the back of the terrace step to the front, levelling it off. Add another tier of building materials at the back to create the second step of your terrace. Continue adding as many tiers as needed, making sure that the front wall of your highest step is even with the end of the side trench.
Add plantings to the terrace steps once each tier has been levelled off.
Consult a professional landscaper when building large terraces, to ensure that you install proper drainage and make the terrace walls strong enough to withstand the weight of the soil behind them. Always follow manufacturing instructions when using masonry supplies.