Why Does Your Villa Need Soil Testing?
Before talking about prices, it is important to understand that soil testing is not just a legal formality — it is a real protection for your investment. A soil investigation report determines:
- ✔️ The right foundation type: isolated footings, raft, or piles
- ✔️ Groundwater level and its impact on excavation and waterproofing
- ✔️ Weak or collapsible soil layers that need treatment before construction
- ✔️ Salt content and risk of chemical corrosion to concrete and steel
- ✔️ Design recommendations for the structural engineer
Most importantly: soil testing is mandatory under Saudi Building Code SBC 303 and the Baladi platform for obtaining a building permit.
What Does a Villa Soil Investigation Include?
1) Field Boreholes
Exploratory boreholes are drilled to depths of 10 to 20 metres depending on project size. The number of borings depends on land area:
- Land ≤ 500 m² → minimum 3 borings
- Land 500–1,000 m² → 4 to 5 borings
- Land > 1,000 m² → determined by design and site conditions
2) Standard Penetration Test (SPT)
Performed inside the borehole to measure soil strength and classify soil type per ASTM D1586. Required in all residential building reports under SBC 303.
3) Laboratory Sample Analysis
- Engineering classification (USCS/AASHTO)
- Atterberg Limits for clay soils
- Chemical analysis: sulfates, chlorides, pH
- Organic content if present
4) Final Engineering Report
- Soil layer description and geotechnical profile
- Allowable bearing capacity
- Recommended foundation depth
- Foundation type and concrete grade recommendations
Factors That Affect the Price
Number and Depth of Boreholes
More borings and greater depths mean higher cost. A 10-metre borehole differs significantly from a 20-metre one.
Site Difficulty
- Rocky sites (e.g. Makkah) → need specialised drilling equipment → higher cost
- Coastal saline soil (e.g. Jeddah) → extra chemical testing needed
- Collapsible soil (e.g. Riyadh, Qassim) → Collapse Potential Test added
- Remote locations → additional mobilisation cost
Additional Tests Required
- Plate Load Test — for actual bearing capacity in large buildings and towers
- Collapse Potential Test — for desert/collapsible soils
- Pressuremeter or CPT — for large-scale geotechnical studies
Lab Accreditation Level
Labs accredited by SAAC and accepted on Baladi platform may charge slightly more — but they are the only legally accepted option for building permits. Cheaper unaccredited labs can cost far more in re-testing and delays.
Estimated Price Ranges for a Residential Villa
| Project Scale | Typical Borings | Estimated Range |
|---|---|---|
| Small villa (land ≤ 400 m²) | 3 borings / 10 m depth | SAR 3,000 – 5,000 |
| Medium villa (400–800 m²) | 4 borings / 15 m depth | SAR 4,500 – 7,000 |
| Large villa (> 800 m²) | 5+ borings / 15–20 m depth | SAR 6,000 – 10,000+ |
Cheaper Is Not Always Better
Many owners ask about the cheapest option — but the answer is almost always: cheapest is not best.
Risks of choosing a very low-cost lab:
- ❗ Insufficient borings or inadequate depth
- ❗ SPT tests not compliant with ASTM D1586
- ❗ Report rejected by municipality or Baladi — forcing you to redo the whole investigation
- ❗ Inaccurate recommendations leading to wrong foundation design
- ❗ Structural problems after construction costing tens of thousands to fix
The right criteria when choosing a lab:
- ✔️ SAAC (Saudi Accreditation Centre) accreditation
- ✔️ Accepted on Baladi platform and by government authorities
- ✔️ Calibrated equipment and qualified engineers
- ✔️ Clear scope of work in the offer before signing
Get a Free Quote from Asas Laboratory
Asas Laboratory Company operates certified branches in Makkah, Jeddah, Madinah, Riyadh, and Qassim. Our reports are accredited and accepted by municipalities and the Baladi platform.
To get a free quote for your villa's soil investigation, simply provide:
- Land location (city and district)
- Approximate land area
- Project type (villa, apartment building, commercial)
- Planned number of floors
Our engineer will contact you within 24 hours with a detailed, transparent quote.