You will learn
Look before you dig
Every building, road and pipeline sits on ground that someone had to understand first. The very first step in understanding it is the desk study. In this lesson you will find out what it is, why it matters and what it covers.
- Explain what a desk study is and where it fits in a project.
- Explain why a desk study is worth doing, and who relies on it.
- Describe what a desk study covers.
You do not need any equipment or prior knowledge. Just read, think, and try the short task near the end.
Why it matters
A flat, empty yard
Meet Brindlemere Yard, the fictional site we will follow through this whole course. It is a flat, empty yard at the edge of a small town, beside a river. A developer wants to build homes on it. It looks like an easy site.
Now imagine the builders start digging foundations without any research. They hit old concrete machine bases. They find oily soil around a buried fuel tank. One corner turns out to be a filled-in pond, too soft to build on. And the river floods the lowest part of the site.
Each surprise means stopping work, redesigning, more cost and more delay.
The point
Most of these problems could have been spotted in a few days, from old maps, geology maps and flood maps, before anyone bought the land or started digging. That is what a desk study does. It does not remove risk. It makes risk visible early, when it is cheapest to deal with.
The idea, in plain words
So what is a desk study?
A desk study is research into a site using information that already exists, done before any digging or drilling. Its aim is to answer two questions:
- What is the ground likely to be like?
- What could cause problems for the people, the project and the environment?
It is called a desk study because most of it happens at a desk: reading old maps, geology records, flood maps and other records. It is almost always paired with a site walkover, a careful visit to look at the site with your own eyes.
Think of it as detective work. You gather clues from many places, put them together, and build a picture of what is probably under the surface.
Key words
Site: the piece of land being studied.
Site walkover: a planned visit to look at the site and its surroundings.
Ground investigation: the later stage where people dig, drill and test the ground directly.
Hazard: something that could cause harm, such as soft ground or contaminated soil.
Wherever you are
Desk studies are done all over the world, under different names. In the UK you will hear desk study, Phase 1 desk study or, when it focuses on contamination, preliminary risk assessment. Other countries use their own names, but the desk study is almost always the first stage of understanding a site. On larger projects, much of the same information also supports an environmental impact assessment, which many countries require for major developments.
The names vary. The questions are the same.
The idea, in plain words
Where it fits in a project
The desk study comes early, before anyone spends money on digging or design.
It is often done:
- Before buying land, so the buyer knows what they are taking on.
- To support a planning or permit application. In the UK this is common where land may be contaminated or unstable. Other countries have their own approval processes. You will see how these rules work in Lesson 2.
- Before a ground investigation, so the investigation looks in the right places for the right things.
Who writes it, and who relies on it
Usually written by
Geotechnical engineers, engineering geologists and environmental consultants, often working together.
Relied on by
Developers and clients, designers, planning and approval officers, contractors, and buyers, lenders and insurers.
Because so many people rely on it, the desk study is valuable work in its own right. Some consultancies offer desk studies as a stand-alone service.
It decides what gets looked for
On real projects, the ground investigation is planned from the desk study. If a hazard is missing from the desk study, it is usually missing from the investigation too, and nobody tests for it. A few days at the desk can decide what is found, or missed, for the rest of the project.
The idea, in plain words
What a desk study covers
A desk study answers a set of simple questions. Each one has its own lesson in this course, so this page is also your map of what is coming.
On our site
Starting the Brindlemere Yard desk study
Every desk study opens with an introduction: what the site is, what is planned, and why the study is being done. Here is ours. We will add a new section in every lesson.
Brindlemere Yard: Desk Study Report (fictional example)
1. Introduction
| Site | Brindlemere Yard, at the edge of Brindlemere town centre, beside the River Brindle |
| Area | About 1.2 hectares (a little under two football pitches) |
| Current use | Vacant. Concrete hardstanding, scrub and a few small sheds |
| Proposed use | 36 two-storey homes with gardens and a new access road |
| Purpose of this study | To identify the likely ground conditions and potential hazards before ground investigation and design |
This report is based on existing records and a site walkover. Ground conditions between the points described may vary, and the findings should be confirmed by ground investigation.
Notice the last sentence
A good desk study is honest about its limits. It tells you what is likely, not what is certain. You will learn to write limitations like this in Lesson 8.
Your turn
Write your own introduction
Throughout this course you can build your own desk study alongside ours. Pick a piece of land you know: an empty plot, a car park or a field near you. You will only use public information about it, and it can be anywhere in the world.
Task (10 minutes)
Write four or five sentences covering:
- Where the site is, and roughly how big it is.
- What it is used for now.
- What could be built there. Imagine a project, such as homes, a school or a warehouse.
- Why a desk study would be useful before building it.
Download the desk study template (Word)
Prefer not to choose your own site? That is fine. Follow Brindlemere Yard, and you will get a new practice site for the final assessment.
Quick check
Four quick questions
This is not a test. It simply shows you whether you are ready for Lesson 2. Choose an answer to see the explanation.
Key points
What to take away
- A desk study is research into a site using existing information, done before any digging, and usually paired with a site walkover.
- It asks two questions: what is the ground likely to be like, and what could cause problems?
- It comes early: before buying land, for planning, and before ground investigation and design.
- It makes risk visible early, when it is cheapest to deal with. It does not make risk disappear.
- Many people rely on it, which makes it valuable work in its own right.
- The questions are the same in every country. Only the names and the sources change.
Up next: Lesson 2
Why there are so many documents. Every country has the same four layers: law, policy, standards and guidance. You will learn what each one is for, using the UK as the worked example, and how to find your own country’s version.