First, read the English article below.

Typically these are around 3 feet deep (0.9m) into the soil.  However, there are a number of factors to consider.  If you are digging in high moisture soil, you will need to dig further into the ground.  The same goes for if your foundation will be near/on a hillside.  There is a simple way to test moisture levels in your soil.  Scoop an empty coffee can into the soil, leaving three inches of space at the top of the can.  Fill up the rest of the can with water.  Wait until the water soaks into the soil, and repeat.  Time how fast it takes the water to soak in.  Anything slower than 1 inch per hour means you have very low moisture levels.  Instead of using home methods of measuring, sometimes it is best to call in a professional.  They will be able to provide all of the diagnostics tests which will tell you everything you need to know about the soil you plan to use.  They will even be able to measure the flatness of your soil, and whether or not you need to adjust your foundation's height. This is critical to do before you get started.  You need to contact the proper government officials to give you the proper permits and licenses that will allow you to lay your foundation, and construct your building.  You will also need to get the property surveyed by a contractor, who can give you more valuable information about the land you are building on. You should clear grass, roots, and any surrounding debris.  This is also a great time to use the survey of your property to determine the height of your foundation.  If the planned spot for your foundation is not level, use a backhoe, or shovel to level the area off. Before you dig any holes, it is important to call 811. This is the Digline and you can use it to request that utility companies come out to the site and mark areas where any pipes or wires might be. This will help to ensure that you do not damage any of the pipes or wires running underground and increase the safety of your project. Call at least a few days before you plan to start digging. You can use a... 

Now, please write a short abstract for it in Indonesian. Abstract:
Tentukan kedalaman fondasi. Susun rencana pembuatan fondasi. Bersihkan area di sekitar fondasi. Hubungi dinas terkait. Gunakan backhoe untuk menggali fondasi. Pasang besi beton (rebar) untuk kaki fondasi. Tuangkan lapisan semen beton pertama. Gunakan roskam untuk meratakan semen.