We have years of experience in the development of 3D ground models for a wide variety of sectors. Including house and road building, waste management, maritime, onshore and oil and gas, aviation, utilities etc. Using data captured by our survey partners or yours, our engineers can take your data and produce 3D ground models to assist with further development and processing such as:

  • Site planning
  • Site evaluation with graphical and contour display of slope, aspect, height, runoff
  • Earthworks design, including cut & fill calculations
  • Other volumetrics such as pavement layer quantities, concrete quantities, cavern and reservoir volumes etc.
  • Road design including horizontal and vertical alignment
  • Visibility studies
  • Plan, long section/profile and cross-section drawings

3D Ground Modelling

3D ground modelling is an essential tool for site planning, siting and designing infrastructure. It can also be used for assessing geotechnical and geohazard risk.

With state of the art 3D ground modelling software, we can create a contoured 3D map that gives a realistic visual representation of the shape of the site that’s being measured.

Volumetric Survey

Volumetric surveying is a type of land survey used for a range of construction projects. Architects and engineers use volumetric data to calculate the volume and value of earthworks, stockpiles and other materials.

Similarly to a topographical survey, they accurately represent an area but the procedures of a volumetric survey pay closer attention to levels and break lines producing a fuller picture of the volumes of land and materials on the premises.

The benefits of ground modelling and volumetrics

Ground modelling and volumetric calculations have a variety of benefits. They can be used for the following reasons:

  • Assisting disputes regarding landfill or excavation
  • Assisting in the design of urban areas
  • To produce accurate volume survey calculations that are needed to monitor earthworks during construction
  • Reduce delays on site

Frequently Asked Questions

What is Ground Modelling?
Ground Modelling, in general, is the process of taking information captured by land survey and processing it to form a continuous 3D surface area of terrain, with all features of interest represented.

Ground Modelling is also sometimes known as Terrain Modelling, particularly when it applies to a large area of land, or Site Modelling, when it applies to a smaller area of land, typically a construction site.

The ground model itself is usually represented by a 3D triangular mesh, with the vertex of each triangle having a x,y and z coordinate in space with reference to some datum. In the UK, the datum is usually the Ordnance Survey (OS) grid but a local project datum and reference grid can also be used if the model does not need to tie back into the national OS grid.

Furthermore, it's important to represent key features in the 3D model correctly by using ‘feature lines’. If feature lines are not specified and the process of ‘triangulation' is done on a purely random, unconstrained basis, then the 3D surface will not be properly reproduced, leading to errors in surface topography and volume calculations.
Triangulation is the process carried out by the application software, using an algorithm, to connect the x,y,z points in space and the ‘feature lines’ to create the continuous 3D surface connecting all points in the ground model.

Triangulated models frequently contain thousands of triangles but can often be much larger, sometimes containing hundreds of thousands or even millions of triangles. It depends on the size of the 3D surface being modelled and the frequency (or resolution) of the observations captured by the survey process.

In common parlance, the 3D triangulated ground model is known as a Digital Terrain Model (DTM).

It can also be known as a Triangulated Irregular Network (TIN).
Feature Lines, depending on which application software is being used, can also be called ‘Break Lines’ or ‘Strings’.

These typically mark changes in slope or other linear features within a 3D Ground Model, for example:

  • The centreline (crown line) and edges (channels and kerbs) of a road

  • The top and bottom of ‘cut’ and ‘fill’ embankments or other constructional earthworks (also called ‘top of batter’ and ‘toe of batter’)

  • Ditches

  • Edges of building slabs (the footprint)

  • Edges of surface car parks and any other changes of slope within the car park

  • Fence lines


The use of Feature lines in a 3D Ground Model is crucial for the correct representation of a surface.
Historically, land surveyors would capture 3D terrain data using a Total Station and process it to produce a Topographic Survey.

However, there is an increasing tendency for site data to be captured by Laser Scanner which produces a dense Point Cloud of x,y,z coordinates from which feature lines can be extracted.

On a larger scale, where many square kilometres (or even hundreds of square kilometres) of terrain are being surveyed, another technique known as LIDAR is often used (Light Detection And Ranging) and the survey can be carried out aerially.

Need survey scanning services?
3D ground models are used by civil engineers, architects, construction companies and developers for:

1. Evaluating the overall situation of an existing or potential construction site, with particular reference to matters such as:

  • Slope gradients and slope aspect

  • Water flows across the surface

  • Production of contour plans

  • Production of long sections through the terrain

  • Visibility studies, either for purposes of safety or for environmental intrusion

  • Photo-realistic visualisation of an existing site before proposed works begin


  • 2. The basis of an infrastructure or landform project design, typically involving:

  • Horizontal and vertical road alignment design

  • Small scale road design e.g. residential housing schemes, business parks

  • Earthworks, with particular reference to achieving a balance between ‘cut’ and ‘fill’.

  • Optimisation of building slab levels and positions for residential housing and commercial building schemes

  • Layout and sizing or drainage schemes

  • Calculation of construction material quantities (‘volumetrics’)

  • Management of earthworks/mineral deposits on large schemes, mines, quarries etc.

  • Landscaping of golf courses, recreational parks and leisure facilities.

  • Calculation of flooded areas/water impounding volumes

  • Visualisation of proposed schemes

AutoCAD and working in 2D is still very much the backbone of design in the construction industry. Making the transition to a 3D approach is worthwhile for those companies who have a regular flow of projects which need to consider the 3D aspect of a project. For many schemes, this is not the case.

For those projects where the 3D aspect is important i.e. where there are significant changes in level over the area of the project, then Benchmarq’s Ground Modelling Services provide a useful intermediate stage between a 2D-CAD only approach and the larger commitment required to invest in 3D ground modelling software, appropriate training and the first few projects to acquire meaningful experience.

Our engineers and technicians have many years of experience in the application of 3D ground modelling and civil design software and can work up your scheme quickly and efficiently from either 2D CAD drawings or raw survey data. We can also arrange for your scheme to be surveyed by one of our experienced survey partners if you have not already had it done.
In the end, it’s all about quality, accuracy, productivity and cost.

For some projects, it is simply not possible to work up a scheme without resorting to 3D ground modelling. On others, it may be more marginal and difficult to make the case.

One of the key factors in this decision may be the cost of getting a design decision wrong.
Construction costs are high, even for an apparently mundane activity such as removing surplus spoil from a site.

Getting that calculation wrong by not considering the 3D aspects involved could be much more expensive than commissioning Benchmarq to provide 3D ground modelling services for your project.

Find out more about our other services such as 3D BIM modelling and CAD Services
This is dependent on a number of factors, such as:

  • What is the source data for the project? CAD drawings or survey data?
  • Do you require us to arrange a survey of the project or have you had one done already?
  • The size of the project.
  • What is it that you want from the project? Just an assessment of an existing site? Do you need a proposed design to be modelled and optimised (for earthworks balance for example?)

    This list is not exhaustive and we will ascertain all the information we need in order to prepare a priced proposal or quotation for you.

    If the package of work can be defined, we will offer a fixed price and an estimated timescale for the work to be completed. Most of our projects fall into this category.

    Where the work cannot be precisely defined, we will offer you an hourly rate and some indication of how long we think the initial tranche of work will take. We are happy to provide timesheets for hourly billed projects.

    Our prices are competitive and we will always be upfront about our rates when we discuss work with you. Nobody likes unpleasant surprises. Get in touch to find out more.
Absolutely not! All project work is done here in our UK offices by our experienced in-house consultants.

Having executed many projects over the years, our view is that although ‘off-shoring’ might appear at first sight to be attractive financially or in terms of getting a large project done quickly, the effort required to inspect and control the quality of the output would be just as great as doing the work in-house in the first place.

Find out more about all of our services
In general “no job is too small” and, by the same token, we have a team of sufficient size to manage large projects (our largest project to date required over 2000 hours of work).

We have worked on projects ranging in size from residential properties to large nuclear power stations.

We have the experience to model projects across the construction industry, including fine architectural detail in buildings, complex plant and pipework, structural steel and site terrain.

Take a look at some of our recent projects.
Our staff are security cleared to work on government projects and we hold a ‘Cyber Essentials’ certificate for our computer systems and procedures.

Find out more about the Benchmarq team.
© 2021 Benchmarq Ltd | Privacy Policy | Jobs
Benchmarq Ltd - Registered in England No. 05402391 - VAT No. 858 741 874 Registered office c/o Richard Place Dobson, 1-7 Station Road, Crawley, West Sussex RH10 1HT