What is site investigation?

Site investigation (or due diligence) is the process of conducting surveys on a site before starting a development. These surveys give you a full understanding of the land you’re using: everything from ground, water and subsurface conditions to flood risks and noise impact.



Carrying out proper due diligence ensures that projects progress only after ruling out any major risks or nasty surprises. It makes development run smoothly and cuts the risk of being forced into expensive changes down the road.

Site Investigation Checklist

The only site investigation checklist you need

Download our site investigation checklist, which covers the 13 site investigation surveys you need to complete on every site. This includes a rundown of why you need each of them and at what stage throughout the project lifecycle.

Site Investigation Checklist

The only site investigation checklist you need

Download our site investigation checklist, which covers the 13 site investigation surveys you need to complete on every site. This includes a rundown of why you need each of them and at what stage throughout the project lifecycle.

Who should conduct a site investigation – and why?

Anyone developing, buying or selling land should carry out proper due diligence at an early stage.

When is it required?

A full site investigation should happen in the earliest stages of development. Here’s why:


  1. This is the best time to identify and mitigate any risks – otherwise fixing them becomes very expensive. Identifying and designing around utilities on the site, for example, is potentially much more cost effective than being forced to change plans due to unexpected pipes or cables.

  2. Surveys are necessary for planning. They will identify issues that planning committees will consider, such as noise, building height or density or the presence of heritage assets.

  3. Surveys are necessary for design teams. For example, engineers must understand ground conditions to design suitable foundations, while architects need a detailed topographical map, showcasing the opportunities and constraints of the site, in their designs.

A successful development depends on detailed site investigation before the planning stage.

What is the risk of not conducting surveys early?

Projects without a clear understanding of conditions risk incurring major abortive costs – money spent on works that are either no longer needed or must be redone.


For example, you might spend upwards of £100,000 on the design team – architects, structural engineers, planners and construction experts – only to later discover problems in ground conditions and find asbestos, contamination or utilities in the way. The lack of previous risk assessment grinds the project to a halt and you’re left out of pocket.


This happens all the time. Developers often risk hundreds of thousands instead of spending a fraction of that early to get surveys done properly.

What surveys should you do as part of a full site investigation?

A wide range of surveys are recommended, covering everything from topographical surveys to preliminary ecology assessments.


In order to mitigate your development risks, we recommend developers complete these 13 surveys as a minimum:

Some of these surveys are desk studies (or desktop surveys), which means they can be done remotely, while others are on-site surveys and must involve a site visit. Click on each of the above for more info.


For a full breakdown of each survey and when they are required, download our Site Investigation Checklist here.

How does the current site investigation process work?

Traditionally, site investigation is a complex process that takes more than four weeks of in-house management time – per site.


Here is what developers have to do on each site:

  1. Identify all the required surveys

  2. Shortlist suppliers for each service – you should identify at least three suppliers for each survey to get a competitive price

  3. Qualify each supplier – each supplier needs to fill out a pre-qualification questionnaire (PQQ) to prove they have the right qualifications, training, finances, insurance and track record to safely complete the work.

  4. Create a scope of service – an often forgotten step, but you should set out exactly what information you require from each report so quotes are returned on a like-for-like basis.

  5. Tendering and procurement – send out the instruction to tender (ITT) which will include site information, tender instructions, scopes of service and contracts. Review quotes and assess and select the right suppliers. Finish this with all the paperwork and contracts for all 13+ surveys.

  6. Manage work and site visits – you will need to arrange site access and approve the risk assessment and method statement for each of the on-site surveys

  7. Read and digest all technical reports – suppliers will start sending emails and Zip files of their 30-40 page reports. You will need to read and understand each in order to collate all the recommendations and decide how to proceed on the site


How does RenKap’s Site Investigation platform simplify the process?

Watch our video to see how RenKap works

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Watch our video to see how RenKap’s Site Investigation platform simplifies site investigation?

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Can RenKap save me money?

Our existing clients save an average of £36,000 per year on management costs alone.




Our platform reduces our clients management time from over 4 weeks per site to under 1 hour. Assuming an average salary of £40k and including employee on costs, that 4 weeks costs our clients approx £1k. RenKap therefore allows our clients to save over £4k per site and our average client uploads 10 sites per year = average client saving of £34,000 per year.


If you want to calculate your own ROI this is how you can do it:

a. Find out how many sites you commission site investigation surveys on per year

b. Calculate how long (in weeks) it would take your team to manage the Current Site Investigation Process mentioned above

c. Calculate how much 1 week of your teams time would cost you [(Average salary + 20% on costs) / 52]

d. Yearly management cost on site investigation surveys = (a X b) X c

e. Potential yearly saving using RenKap = Deduct our subcription fee of £6k from your calculation in d.

f. ROI = d / subscription cost


 As an example, let’s say that it takes your team 4 weeks to manage the site investigation process per site and your weekly cost = £1k. Based on the above you can expect the following savings and ROI:

– Clients with 2 sites per year: £2,000 saving and ROI of 1.3X

– Clients with 5 sites per year: £14,000 saving and ROI of 2.3X

– Clients with 10 sites per year: £34,000 saving and ROI of 6.7X

– Clients with 25 sites per year: £94,000 saving and ROI of 17X

– Clients with 50 sites per year: £194,000 saving and ROI of 33X


Our clients can break even on just 2 sites per year.


Additional savings via RenKap:

– More competitive net costs from our suppliers

– Minimise abortive costs and expensive mistakes at later stages in the project