architect

Building a home on the Costa Blanca involves much more than designing appealing plans or choosing the plot with the best views. One essential step—often overlooked—is carrying out a geotechnical study on the Costa Blanca before starting any construction project.

This report provides crucial insight into the characteristics of the land where you intend to build, ensuring the project’s safety, stability, and viability. In this article, we explain why it's so important, what it involves, and when to do it if you want to build confidently in the Comunidad Valenciana.

What is a geotechnical study?

A geotechnical study is a technical report carried out by specialists to analyse the composition, resistance, and behaviour of the soil. It includes:

• Boreholes and trial pits (typically between 3 and 6 metres deep)
• Soil sampling
• Laboratory testing for load-bearing capacity, moisture, expansiveness, etc.
• A final report with recommendations for foundations and construction

This document is legally required to build a detached house on urban or developable land.

Importance of a geotechnical study on the Costa Blanca

The Costa Blanca features a wide variety of soil types: rocky terrain, clay-rich soils, artificial fills, sandy coastal areas, and more. Because of this diversity, you can't rely solely on the appearance of the plot or on what a neighbour may have done on their property. A good geotechnical study on the Costa Blanca allows you to:

• Avoid risks such as structural cracks due to settlement
• Determine the most suitable type of foundation
• Adapt the architectural project to the reality of the site
• Estimate real costs from the outset and avoid unexpected overruns

In towns like Dénia, Jávea, Moraira or Altea—where sloped terrain and varied subsoil are common—this study is particularly relevant.

When to carry out a geotechnical study on the Costa Blanca

The best time to commission the geotechnical study is before drafting the final architectural project, once the plot has been selected. This allows the architect to design based on the actual conditions of the site, avoiding the need to revise plans later. The study is carried out by a company specialising in geotechnics, usually contracted through the architect or architectural firm. The team typically includes geologists, engineers, and lab technicians.

How much does a geotechnical study cost in the Comunidad Valenciana?

The cost of a basic geotechnical study for a detached home generally ranges from €600 to €1,200, depending on:

• Type of terrain and site accessibility
• Depth and number of boreholes
• Whether advanced testing is required

While it may seem like an extra upfront cost, it's an investment that prevents far more expensive issues during the build or after completion.

Risks of building without a geotechnical study on the Costa Blanca

Some individuals attempt to cut costs by skipping this step or using reports from nearby plots. This can be a serious mistake. Common risks include:

• Cracks in walls or floors due to uneven settling
• Damp or leaks due to insufficient drainage
• Over-engineered foundations that are unnecessarily expensive
• Work stoppages if problems arise once excavation begins

Additionally, without this study, you can't obtain a building licence or secure architectural approval from the relevant college.

Our approach at La Quinta Fachada

At La Quinta Fachada Arquitectura, we believe in architecture that grows from the realities of the land. That's why we recommend all our clients commission a geotechnical study right from the start. It allows us to design with precision, avoid surprises, and create homes that are safe, integrated into the environment, and tailored to the unique conditions of the Costa Blanca. If you're planning to build in the area, get in touch and we’ll guide you from plot selection to the final design of your home.