Site geology & geodesy

When soil investigations are needed, what they provide, and cost

Key questions

When geology is mandatory

Mandatory under building code for CC2/CC3 (>2 floors, complex objects). For a one-storey private house formally optional, but choosing a foundation without it is guessing.

What geology gives you

Soil layers, groundwater level (GWL), bearing capacity (R0), frost heave, optimal depth. This drives the foundation type and its cost.

Work scope & prices

2–3 boreholes 6–10 m + lab + report: ~$400–800. Site topo survey 1:500 — $100–200. Fieldwork 1 day, report 1–2 weeks.

Geodesy

Setting out house axes, tying to boundaries and red lines, control measurements during construction. Separate from geology.

Risks without it

High GWL → floating foundation; heaving soils → cracks; peat/fill → settlement. Foundation repair costs more than the foundation.

How to order

Licensed geotechnical company; the report must include borehole sections, test tables, R0 and GWL conclusion, foundation recommendations.

Geology costs ~0.5% of the house budget but determines 15% of spend (the foundation). A common mistake is copying a neighbor's foundation: GWL and layers can differ 20 m apart.

Over Bouwgrond & geodesie — wanneer nodig

Bouwgrond & geodesie — wanneer nodig — Wanneer grondonderzoek nodig is, wat boringen en lab opleveren, kosten, risico's zonder onderzoek.. Bouw: schatting, installaties, bouwgrond, vergunningen, winterbouw, oplevering, verzekering, termen. Gebruik onze tools zonder registratie of software-installatie. Alle berekeningen gebeuren in uw browser — uw gegevens worden nooit naar een server gestuurd.