Ground Investigation Before You Build
Ground investigation (GI) is how designers learn what the ground will do before foundations and drainage are fixed. Trial pits, boreholes, in-situ tests, and laboratory results feed the foundation strategy.
Mainline builds from the resulting design. We do not replace specialist GI contractors, but we rely on clear reports to avoid formation surprises.
review Piling Contractors in Tonbridge and Groundworks Contractors in Wandsworth.
When investigation is needed before you build
Before finalising foundation type; before pricing high-risk groundworks; on brownfield plots; and whenever Building Control or warranty providers expect evidence of ground assessment.
What investigation methods deliver
A typical desk study plus intrusive investigation may use trial pits for shallow profiling and boreholes for deeper strata and sampling. The report should describe strata, groundwater observations, geotechnical parameters, and foundation recommendations — with limitations stated.
Method choice is covered in detail on /ground-conditions/trial-pits-vs-boreholes. Pricing impact of late GI is covered in Insights.
If this matches your project stage, send drawings and site details for a scoped quote — or call to talk through programme and access constraints.
Get an Accurate QuoteMethod comparison
| Need | URL owner |
|---|---|
| Trial pits vs boreholes (methods) | /ground-conditions/trial-pits-vs-boreholes |
| Price impact of GI findings | /insights/trial-pits-boreholes-change-groundworks-price |
| Commercial ground risk narrative | /guides/ground-conditions-risk-explained |
When scope usually expands
- No GI on a non-trivial build
- Trial pits only where deeper info is needed
- Brownfield or made ground suspected
- Warranty or BC requesting ground evidence
- Quotes assume strip without GI support
How reports inform foundation and drainage design
Issue GI to the structural engineer early. Update tenders when recommendations change foundation type. On site, compare formation with the expected strata.
Briefing checklist for GI
- Proposed footprint and loads shared with GI provider
- Contamination scope considered on brownfield
- Report issued to structural engineer
- Tenders updated after recommendations
From brief to design use
Step 1: Brief the investigation
What this step delivers: Scope matches building and risks.
Step 2: Intrusive works and testing
What this step delivers: Data collected.
Step 3: Report into design
What this step delivers: Foundation strategy updated.
Step 4: Construct to design
What this step delivers: Formation checked against expectations.
What affects investigation scope and cost
GI costs little compared with redesigning foundations mid-contract. Skipping GI to “save money” is a common false economy.
Frequently asked questions
Do I always need boreholes?
Not always. Depth of influence, structure type, and ground risk decide. Your geotechnical advisor scopes the methods.
How This Issue Is Normally Diagnosed and Repaired
Follow the typical path from problem identification through to resolution:
We provide these services across the UK, including
Get a Free Quote
Contact us for a no-obligation quote or to discuss your project. We'll advise on the best approach and provide clear pricing.
Get an Accurate QuoteHave a GI report and foundation design? Request a groundworks quote.
Related Services
Full-service groundworks for commercial and residential construction.
Piling ContractorsPiling for new builds, extensions and structural works on difficult or tight sites.
Foundation ContractorsCommercial and residential foundation contractors: strip, raft, pad and piled solutions to engineer's design.
Related Topics
Related Groundworks Guides
Contact Us
Discuss Your ProjectGround Investigation Before You Build FAQ
Do I always need boreholes?
Not always. Depth of influence, structure type, and ground risk decide. Your geotechnical advisor scopes the methods.
Need project guidance?
Share your site details and priorities. We will outline a practical scope, likely timeline, and next steps.