WHAT IS A TOPOGRAPHICAL SURVEY?  

A topographical survey, often referred to as a topo survey, is best described as a comprehensive assessment of the physical characteristics of a piece of land, including physical and manmade features. This survey captures essential details such as elevation changes, contours, vegetation, bodies of water, structures, and other significant features. These surveys also give you an accurate definition of the boundaries of your land, so you know where you can and can’t build.

A topographical survey is one of the most fundamental steps in the early self-build process, and should be carried out before any design work is undertaken.

WHO IS INVOLVED IN A TOPOGRAPHICAL SURVEY?  

A topographical survey is carried out by a land surveyor, who is typically hired by the self-build client. They use specialised equipment such as GPS systems, laser scanning and drones to meticulously map out the terrain with precision and accuracy.

Once the survey has been completed, the drawings will be sent to your architect, technologist, engineer and any others involved in the design process. These drawings come in either a 2D or 3D form, and the information is used as a base for the design work.

DOES MY PROJECT NEED A TOPOGRAPHICAL SURVEY? WHAT ABOUT PLANNING PERMISSION?

The short answer is yes. A topographical survey is required for construction work on piece of land, including new buildings, major renovations or installation of a drainage system. A topographical survey is of extra importance if your site sits on multiple levels or if the proposed structure is close to your boundary lines.

Having an inaccurate/no topographical survey can lead to a lot of problems further on in the process, such as setting the ground level incorrectly or building over your boundary line. A survey can help identify any potential issues before any construction begins.

Architects, technologists and structural engineers incorporate topographical survey data into their designs to ensure the proposed structure is sympathetic to the natural landscape. This data also helps to work out the position of the house, which minimises the need for extensive and expensive groundworks.  

These surveys can also act as a legal document defining the boundaries of your property, which is handy for any potential boundary disputes.

You technically do not need a topographical survey for planning permission. However, the data collected helps your design team know what needs to be done to comply with planning permission rules. Whether it's setbacks, height restrictions, or environmental protections, having accurate survey data ensures that your project meets all necessary standards.

Unless you have surveying experience, we do not recommend carrying out your own topographical survey. This is due to the high level of detail required and the use of highly specialised (and rather expensive) equipment. Hiring a professional guarantees quality work within a small amount of time.

Your role as a client in the topographical survey process is choosing the right surveyor, as even the slightest mistake can prove costly down the line. Here are a few things to look for when choosing a surveyor:

• That your surveyor has the right experience for the job
• That the company is the correct size, as larger projects may require multiple surveyors
• That they have the correct technology for your requirements
• That they have the correct PI insurance in place

A good place to look would be the Royal Institution of Chartered Surveyors website, where you can find reliable surveyors local to you.

HOW MUCH DOES A TOPOGRAPHICAL SURVEY COST?

In our experience, a survey package for a typical self-build plot costs around £1000 plus VAT. This is split into two parts. The first part is the time to carry out the survey on-site (this can cost between £300 and £600 per day) and the time needed to create the drawings from the collected data (which also costs between £300 and £600). Most land surveyors will assess your project and give you a quote beforehand.

These numbers are influenced by a few factors. The size of your land is an obvious one, as a larger area will take more time to survey. Surveyors include travel time in their fees, so it’s important to find one local to you. Any extensive 3D modelling will also add to the cost.

HOW LONG DOES IT TAKE TO CARRY OUT A TOPOGRAPHICAL SURVEY?

The time it takes to complete a topographical survey can vary widely depending on several factors, including the size and complexity of the area being surveyed, the equipment needed and the level of detail required.

For smaller areas with relatively simple terrain, a topographical survey with drawings might be carried out in 4 – 7 days.

DO I NEED A TOPOGRAPHICAL SURVEY FOR AN EXTENSION?

Whether you need a survey for an extension depends on a few factors. If you have a flat site and your boundaries are already well-defined by walls or fences, then you’d be relatively safe with a simplified survey. A sloping site or a site without clear, marked boundaries would still need a topographical survey regardless of the size of the extension.

Understanding the importance of topographical surveys is essential for anyone embarking on the journey of self-building. These surveys are fundamental to getting your self-build off the ground. They provide crucial information to your design team about the land you are about to build on. Advancements in surveying technologies continue to make the process quicker and more accurate, giving you as a self-builder confidence that your design team is backed by the correct data. While it may require an upfront investment of time and resources, the benefits of a topographical survey far outweigh the costs.