Why Is a Site Survey Conducted During Villa Construction? Types of Foundations and Their Costs

Soil investigation, ...is a geotechnical investigation conducted to determine a plot of land’s bearing capacity, the groundwater level, and the structure of the soil layers. Conducting this study before beginning construction of a villa is both a legal requirement and an essential step for the safety of the structure. Since soil conditions can vary from lot to lot in coastal areas such as Çeşme and Alaçatı, the results of this study form the foundation for the design phase.

What Is a Soil Study, and Why Is It Required?

Soil investigations, drilling studies, and laboratory tests determine the soil’s bearing capacity, settlement potential, and seismic behavior. Under Law No. 6306 on the Transformation of Areas at Risk of Disasters and relevant zoning regulations, a geotechnical investigation report is required for a building permit application. A structural design cannot be prepared without this report, and a building permit cannot be obtained without the structural design.

Foundation Types Based on the Results of a Soil Investigation

Different foundation systems are selected based on the bearing capacity and soil layers identified in the feasibility study:

• Singular base: An economical type of foundation applied beneath columns on solid ground with high bearing capacity.
• Continuous (perpetual) basis: A system used on floors with medium load-bearing capacity, in which wall and column loads are distributed in strips.
• Mat foundation: A foundation that covers the entire base of a structure and distributes the load over a wide area on soils with low bearing capacity.
• Pile foundation: A system consisting of reinforced concrete or steel piles that transfers the load to a stable layer deeper in the ground when the surface soil is insufficient.

Factors Affecting the Cost of a Site Investigation

The cost of a geotechnical investigation varies depending on the lot size, the number and depth of boreholes, the geological structure of the soil, and the scope of laboratory testing. Plots located near the shoreline may require additional testing due to high groundwater levels, which can increase the cost somewhat. Although the cost of the study is a small item within the total construction cost, it is far lower than the future repair costs that could result from an incorrect foundation selection.

At İmerek Yapı, we perform structural design for our villa projects based on the results of soil investigations, and we determine the foundation system using this data. Project Services On our website, you can learn about our architectural and structural design process, Rough Construction You can also review our application process on our website.

Frequently Asked Questions

Can construction begin without a soil study?

No. A structural design is required for a building permit application, and a geotechnical investigation report is required for the structural design.

How long does a soil survey take to complete?

Depending on the plot size and the number of boreholes, fieldwork takes a few days; including the laboratory and reporting phases, the entire process is typically completed within two to three weeks.

Who determines the base type?

Based on the data in the geotechnical investigation report, the structural engineer determines the foundation system appropriate for the structure’s load and the soil’s bearing capacity.