How to complete a topographical survey on your site
The key to any successful development is site investigation: doing the necessary due diligence that gives you all the information you need to progress smoothly, within your budget and without any nasty surprises.
Site investigation should start with a topographical survey, which produces an accurate, detailed map of your site. In this article, we set out the steps you would usually have to take to complete a topographical survey.
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.
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.
Why do you need to start with a topographical survey?
The topographical survey lays the foundation for the rest of the site investigation process – and the development as a whole. The survey broadly does two things:
It reduces the risk of expensive and time-consuming abortive costs (costs incurred from mistakes or work that has to be redone) by providing a clear understanding of the site, its boundaries and constraints. These details will be crucial in the design process.
It forms the basis of subsequent surveys. Other site investigations, such as utility surveys, will require a topographical survey to pinpoint any of their findings on that initial study.
Step 1: Understand who can complete a topographical survey
Anyone doing a topographical survey must abide by the Construction, Design and Management Regulations 2015 and Health and Safety at Work etc. Act 1974. They must also be a competent member of The Survey Association (TSA).
Step 2: Qualify suppliers to find competent ones
When looking for suppliers, you need to conduct a pre-qualification questionnaire (PQQ). This will ask the supplier to prove their technical skills and qualifications. Core questions will include details such as:
Financial information, including the previous year’s revenue
Insurance: employer’s liability insurance, public liability insurance, professional indemnity insurance
The PQQ will also cover technical questions such as:
Does the supplier’s business abide by the relevant legislation (see above) and use TSA members?
Does the business provide quality control procedures in their report, including (but not limited to) self-checks by the author, factual checks by another appropriate person and sign-off by a supervisor?
Does the business provide a programme of works, fixed costs, method statements and risk assessments in their survey?
Step 3: Define the scope of the topographical survey
You will want to ensure that potential suppliers understand exactly what you want the topographical survey to show. To do this, you will have to create a scope of service that outlines what the report will include in terms of both content and format. This will ensure that the finished report is reliable and that all suppliers quote for the project on a like-for-like basis. For a guide to what topographical surveys should include, read our guide here.
Step 4: Tender the survey to at least 3 suppliers
Once you have a scope of service, you will need to issue an invitation to tender (ITT) to suppliers who have passed the PQQ. This will include all the details and instructions about the project for the shortlisted suppliers. By issuing ITTs to at least three suppliers, you can guarantee that you receive a competitive tender for your project.
Step 5: Procure your preferred supplier
After you receive responses from your shortlist, you will have to choose your preferred supplier, negotiate terms (though suppliers will usually impose their own terms and conditions) and enter into a contract with them.
Step 6: Manage site visits
You will need to provide the supplier with access to the site. For sites up to 1ha, they should require no more than one day to complete their assessment – though this will depend on how many surveyors are sent to the site and the makeup of the site. Prior to attending the site you will need the suppliers to provide their RAMS (Risk Assessment and Method Statement) for health and safety purposes. These will need to be reviewed and signed off.
Step 7: Receive the finished reports and drawings
Once the survey is completed, you will be sent the final documents – likely by email, Dropbox or WeTransfer. You will then need to review them to ensure that the scope of service has been adhered to.
Step 8: Repeat for the other surveys
Remember, a topographical survey is just the start of the site investigation process. There are 12 other surveys developers should complete when they start a new project. You will have to coordinate the above process with multiple suppliers and keep track of a long list of completed reports.
There is an easier way
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There is an easier way
Watch our video to see how RenKap works