What is CAD and how is it used in engineering and surveying?

CAD, Computer Aided Design, surveying, technolgy,


Computer-Aided Design (CAD) is a digital technology used to assist in creating, modifying, analysing and optimising design for the engineering and surveying industry.

Computer-Aided Design (CAD) encompasses computer systems to assist, create, modify, analyse and optimise a design. It is a digital method for producing two-dimensional (2D) drawings or three-dimensional (3D) models.

The software is crucial in modern engineering and land surveying as it facilitates the creation of precise and detailed designs efficiently and accurately. It enables civil engineers to visualise the product in a simulated environment, test its functionality, and evaluate its performance before manufacturing the physical product.

CAD replaces manual drafting with an automated process, offering a more efficient, precise, and flexible method of designing. It also enhances collaboration among professionals, streamlines the design process, and integrates seamlessly with other technologies. This makes it an indispensable tool for innovative and effective engineering and land surveying design solutions.

Mechanical, civil, electrical, aerospace, and industrial engineers and land surveyors extensively use CAD. It is also used in architecture, interior design, fashion, game design, animation illustrators, city planning and graphic design industries.

History of Computer-Aided Design

The term ‘Computer-Aided Design (CAD)’ emerged in the 1950s when the first numerical control programming system was created. Simple 2D drafting systems and sophisticated 3D modelling and simulation programs were evolved in the 1960s. CAD systems became more accessible to engineers and architects as computer technology advanced and became more affordable.

The new AutoCAD program launched in 1982, making it available across all personal computers. Since then, Computer-Aided Design has continued to evolve, and new technologies such as 3D printing and virtual reality have become indispensable tools in engineering, land surveying, and design.

How CAD is used in the civil engineering and surveying industry

Engineering professionals utilise CAD to design and plan various infrastructure projects, such as roads, bridges, dams, and water systems. It allows for creating precise plans, elevations, and cross-sections, ensuring adherence to certain standards and specifications. Additionally, CAD software enables the simulation and analysis of different design aspects, such as stress tests on materials and load-bearing analyses for bridges.

Land Surveyors use CAD for accurate topographical mapping. These maps are vital in construction planning to provide terrain information such as land features, elevations and gradients. Surveyors also use CAD in site development and layout planning to help determine the optimal placement of buildings, roads, and other infrastructure elements.

Click here to read more about what a Land Surveyor does.

For Engineers and Land Surveyors to utilise CAD, they will need to install a CAD software package and may occasionally require a graphics card for the system to work. The mouse and keyboards are generally used as input devices and trackballs.

CAD Key Features and Capabilities

CAD has various key features and capabilities that collectively revolutionise the design process across the engineering and construction industry. 

Precision and accuracy 

The software system can deliver precision and accuracy compared to traditional hand-drawing methods. This precision is critical in reducing errors and ensuring that all design aspects adhere to the exact specifications and tolerances.  

3D modeling and visualisation 

CAD’s 3D modelling and visualisation abilities allow engineers to create detailed three-dimensional representations of projects. This provides a realistic view of how designs function and appear in the real world. The visual clarity aids in better decision-making and helps convey complex concepts to non-technical stakeholders.

Advanced simulation and analysis tools 

The system tools enable designers to test and analyse a design’s performance under various conditions, including temperature, pressure, or stress before construction begins. This predictive capability helps identify potential flaws and optimises design, which enhances safety and functionality. 

Time efficiency and flexibility 

CAD significantly accelerates the design process and helps with the ability to make quick and iterative changes. This increases productivity and responds rapidly to changing requirements. 

In terms of flexibility, users can tailor tools and workflows to specific project needs, enhancing the software’s effectiveness and user efficiency. This flexibility allows CAD to be adapted to a wide range of industries and project types. 

Information sharing and documentation 

Currently, the CAD system features easy sharing and collaborative work, which allows Engineers or Surveyors to contribute to and review a design simultaneously. The software also generates detailed documentation such as technical specifications, materials lists, and dimensions. This documentation is essential for the construction and manufacturing process to ensure that all project details are accurately captured and communicated. 

Integration with other systems 

Integration with other digital systems is a significant advantage of CAD. Many CAD programs seamlessly integrate with other software, such as Computer-Aided Manufacturing (CAM) and Building Information Modeling (BIM). This integration streamlines the transition from design to production or construction, enabling a smoother workflow and reducing potential errors.

What is BIM and how is it used in Civil Engineering?

CAD Softwares

There are specific software programs available for Computer-Aided Design.


AutoCAD is one of the first softwares to launch and is widely recognised for its extensive 2D and 3D design capabilities. It is mainly used in the engineering, construction, and architecture industries to facilitate precise drafting and modelling abilities. It offers tools for creating detailed design plans, complex mechanical parts, and intricate engineering drawings.

This software allows for customisation and integration with other applications, making it a standard in various design-related fields. It can handle large datasets and designs, making it a top solution for engineering professionals seeking detailed and accurate design outputs.


SolidWorks specialises in 3D modelling and is widely used in mechanical engineering. Developed by Dassault Systèmes, it stands out for its parametric and feature-based approach, which allows designers to create models based on real-world behaviours and properties.

It enables Engineers and Land Surveyors to test and refine their designs under various conditions, making it renowned for its friendly interface and robust simulation capabilities. SolidWorks is ideal for product design, machinery manufacturing, and complex engineering projects, as it offers tools for assembly modelling, element analysis, and kinematic studies.


FreeCAD is an open-source parametric 3D CAD modeller with more robust capabilities for intermediate to advanced engineering and surveying users. It is particularly useful in mechanical engineering and product design due to its parametric design approach, which allows users to easily modify designs by going back into the model history and changing its parameters.

FreeCAD supports various modelling techniques, including 2D sketching and 3D modelling, and can produce detailed and dimensionally accurate models.


Developed by Autodesk, Inventor is a prominent CAD software known for its robust 3D mechanical design, simulation, and documentation capabilities. It allows engineers to iterate and refine designs quickly as it integrates parametric, direct edit, and freeform modelling tools.

The strength of the software lies in its ability to simulate real-world conditions, enabling professionals to analyse how a product can perform under different stresses. Its user-friendly interface and advanced design and engineering tools make Inventor a preferred choice for professionals looking to develop innovative and technically sophisticated products.

SketchUp is also a popular software program available for CAD. Click here to read more about SketchUp.

Types of CAD

The types of CAD refer to the different methods or approaches. This includes 2D CAD, 3D CAD, 2.5D CAD and CAD with neutral file formats.


Known as two-dimensional Computer-Aided Design, 2D CAD is focused on creating flat, linear drawings and designs. This form of CAD is used for drafting and detailing, where depth and volume are not required. It is essential in civil engineering, electrical design, architecture, and surveying, where precise floor plans, writing diagrams, and architectural layouts are created.

The drawings can include dimensions, annotations, and other relevant information for construction and other design-related tasks. The strength of 2D CAD lies in its simplicity and precision, making it an ideal tool for construction projects where complex 3D modelling is unnecessary.


3D CAD is a more advanced form of CAD technology and allows for the creation, manipulation, and visualisation of objects in three dimensions. This type of CAD is crucial in mechanical engineering, product design, and animation, where detailed modelling of parts, assemblies, and characters is required.

3D CAD software, such as SolidWorks and Inventor, offers tools for building complex shapes, rendering realistic images, and simulating how a product or part will function in the real world. These programs allow designers to see every aspect of their creation, which enables them to test fit, movement, and other functionalities.

The ability to visualise a product in three dimensions before it is built is invaluable, as it reduces the need for physical prototypes, saves time, and allows for more creativity and innovation in the design process.

2.5D CAD

2.5D CAD refers to a hybrid between 2D and 3D CAD. Though it doesn’t offer full 3D capabilities, it includes limited three-dimensional design elements. This type of CAD is used in machining and engraving processes, where it is essential to have a flat representation with varying depths. Though it doesn’t provide the complete functionality of 3D modelling, 2.5D CAD is valuable for applications requiring more than a flat surface but not complex three-dimensional shapes.

This intermediate form of CAD bridges the gap between traditional 2D drafting and full-scale 3D modelling, offering a balance of simplicity and enhanced capabilities.

CAD with neutral file formats

The types of CAD can also be distinguished based on the file formats they use. Some systems use neutral file formats like STEP or IGES to allow interoperability between different CAD systems. These formats are crucial for collaboration across different platforms, ensuring that a file created in one CAD system can be opened and edited in another.

On the other hand, CAD software using native file formats is typically optimised for the specific features and functionalities of that software. These native formats offer the best performance and usability within their respective systems but can pose challenges when sharing files with users of different CAD systems.

Each type of CAD and file format offers unique advantages and limitations, making them suited for specific applications and workflows in the diverse design and engineering world.

Challenges of CAD

The initial cost of CAD software and the hardware required to run is relatively high, indicating that it will always be a significant investment for individuals or small firms. Learning to use CAD software efficiently often involves a steep learning curve, as it can be time-consuming and resource-intensive due to extensive training and practice.

Additionally, relying too much on CAD tools can stifle creativity, as engineers may become constrained by the limitations of the software or dependent on its functionalities to solve design problems.

Using CAD software can also increase vulnerability to cyber attacks, posing a significant security risk for engineering professionals as sensitive design data may become a target for hackers.

Overall, CAD’s ability to produce detailed and accurate project representations is fundamental in civil engineering and land surveying. Its evolution is set to transform these fields further, paving the way for enhanced efficiency, accuracy, and creative solutions.

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