Topographical Survey

Essentially, a topographical survey highlights any difference between the true levels and gradients of the land at the project site, and those presupposed in preliminary designs. They are used to identify and map the contours of the ground and existing features on the surface of the earth or slightly above or below the earth’s surface (i.e. trees, buildings, streets, walkways, manholes, utility poles, retaining walls, etc.).

A Topographical Survey can help you visualise the land you intend to develop.  Contours, spot levels and feature lines, accurately define the ground and boundaries so that you can design with confidence.

When used in conjunction with  sub-surface surveys, historic services records search or drainage CCTV surveys, a topographical survey can provide a true picture of the land and the services within them in either 2D Cad or 3D Revit format, allowing for detailed designs to be created.

What are the benefits?

  1.  Having a detailed and accurate picture of your land can reduce the risk of costly downstream mistakes caused by unforeseen issues.
  2.  In the case of purchased land, a topographical survey can reveal any information that might be hidden from plain sight, including the changes that have occurred on the area over a period of time.
  3. Topographical surveys let you understand the land’s topography – knowing the topography of the land around and under any type of structure is important to ensure a durable construction or an efficient modification.

Information and Facts

What is a topographic survey, and what are the objectives of this type of survey?

A topographic survey gathers data about the natural and man-made features of the land, as well as its terrain. Permanent features such as buildings, fences, trees and streams accurately define the ground and its boundaries. Land contours and spot levels show the elevation of the terrain. Topographic maps are used by architects, engineers, building contractors and others to accurately visualise their sites and help bring forward development.

Is there more than one type of topographic survey?

Depending on the purpose of the survey and the desired output, there are a few types of topographical surveys to choose from, including a general land survey, boundary survey, and survey for construction projects. Also, depending on the scale of the map that is required and location of the site, for instance whether it’s an urban or rural area, a survey can be classified by accuracy level.

Tell us about the steps involved in a topographic survey?

A typical topographical survey process includes:

  1. Gathering information, i.e. the geographical area to be included, the level of detail, accuracy and data output
  2. Planning the time schedule and pricing
  3. Gathering survey data on site
  4. Processing data and preparing the final survey output
  5. Internal quality assurance by a senior member of the staff
  6. Delivery of the final survey output to the client

How long does the survey process take?

The duration of a topographic survey process is dependent on the size of the area to be covered and the complexity of the terrain being surveyed. Once we have calculated the time it will take, a programme of works is agreed with the client. This could include additional resources to meet a particular project programme milestone or other deadline.

What would you use a topographic map for?

Normally, a topographic survey is used as a basis for design decisions. An architect or consulting engineer will need an accurate digital plan of their site area to produce good design and construction drawings. The survey and data can also be used for other purposes, including new housing developments, new road layouts, land registry submissions or volumetric calculations.

Is there any special equipment you use to conduct a topographic survey?

Robotic total station instruments are generally employed to detail features on-site. All survey points are measured by the instrument with an onboard feature code list. For example, the surveyor can string survey points to create an outline of a building with a specific code. GPS and laser scanning equipment can also be used, subject to the site specification and terrain.

How would I read a topographic survey?

A topographic survey can be presented in multiple formats; the output is subject to the client’s need. For example, if clients are submitting a survey for Land Registry purposes, then specific scales and outputs are required for compliance. However, the standard output is AutoCAD dwg, and 3D data can also be presented in Revit.

Why is topographic surveying so important for architects?

Architects require accurate digital data of their client’s site to properly design their commissions, with the level of detail or specification tailored to the purpose of the survey.

A thorough survey of all the features is critical for planning, design and construction. Any features that are not surveyed can cause costly delays at any stage of the development.

How much does a topographic survey typically cost?

Costs are based on the time we need to spend on the project. The time is calculated on the extent of the site area, terrain and visibility. The specification will also itemise the features we need to survey, which is also considered in our calculation.

Who are you most regular customers?

We have a wide range of customers who use our services, ranging from architects, engineers and contractors, to housebuilders and private individuals. We have a strong reputation in the industry for providing accurate data on time and on budget. Clients trust us to deliver.