Carlson CADnet PDF BIM and Raster to CAD Conversion Software

Carlson CADnet for converting plans and images into CAD

Carlson CADnet is designed for professionals who regularly receive project information that is not supplied as clean, editable CAD data. It provides tools for turning PDF drawings, scanned plans, raster images and paper plans into useful CAD geometry so the information can continue into surveying, civil engineering, construction estimating or design workflows.

Instead of redrawing an entire project manually, users can trace and digitise the information that matters and convert it into standard CAD entities. CADnet also supports BIM workflows, allowing model information to be brought into the CAD environment and Carlson surface information to be prepared for BIM-based projects.

Convert PDF drawings into editable CAD information

PDF plans are common in tender documents, archived projects and drawings supplied by clients, but a PDF is not always suitable for direct survey or engineering work. Carlson CADnet provides tools for bringing these plans into the CAD environment and converting useful drawing information into editable entities.

Automatic tracing can help identify linework in suitable PDF drawings, reducing the amount of manual redrawing required. Once converted, lines and other entities can be edited, elevated, measured or incorporated into the rest of the project drawing.

This can be especially useful for construction estimators and surveyors who receive a PDF rather than the engineer’s original DWG file. The plan can be converted into working CAD information before quantities, layout data or design geometry are prepared.

Work with scanned plans and raster images

Older projects and tender documents may only exist as scanned drawings, photographs or raster image files. CADnet includes raster handling tools that allow this information to be used as the basis for new CAD geometry.

Users can trace raster linework, snap to information visible in the image and create standard CAD entities over the original plan. Raster editing tools can also be used to clean up source images by working with unwanted areas, speckles and line thickness before tracing.

For companies working with archived drawings, this provides a practical way to bring older information into a modern CAD workflow without recreating the entire drawing from measurements or manual coordinate entry.

Extract text from raster drawings

Carlson CADnet includes Optical Character Recognition tools for converting suitable text visible in raster images into CAD text entities. This can reduce the amount of manual typing required when a scanned plan contains elevations, labels, notes or other text that needs to become part of the editable drawing.

The result will naturally depend on the quality and clarity of the source image, so extracted information should still be reviewed before it is relied on for design or field preparation. On clear plans, however, OCR can make document conversion substantially quicker than manually re-entering every annotation.

Digitise directly from paper plans or on screen

CADnet provides a full set of digitising routines for project information that cannot be converted automatically. Users can digitise points, polylines, areas, contours, profiles, sections and end areas from source plans.

For a surveyor, this may mean extracting historic contours or boundaries from an old plan. A construction estimator may digitise proposed surfaces or material areas from tender drawings. A civil engineering team can recreate profiles and sections needed to continue a design when the original digital project data is unavailable.

By using dedicated routines for different types of geometry, the resulting drawing can contain more useful engineering information than a simple visual trace of the source plan.

Create CAD linework for estimating and construction preparation

CADnet is also one of the modules used within Carlson’s Takeoff workflow. This is important for earthwork and construction users because quantity calculations depend on having usable geometry and elevations rather than simply viewing a PDF in the background.

A contractor can start with a plan supplied as PDF or raster imagery, create the required CAD linework and then continue into surface modelling, quantity calculations or construction data preparation with other Carlson modules. This avoids having to rebuild the same project in unrelated software packages at each stage.

Import BIM information into CAD

Modern building and infrastructure projects increasingly combine CAD and BIM information. Carlson CADnet provides tools for bringing BIM model information into the CAD environment so elements such as walls, doors, windows and roofs can be represented as CAD entities.

This is useful when a surveyor, estimator or civil engineering professional does not need to work inside the complete authoring environment used to create the building model, but still needs relevant geometry for coordination, measurement or drawing production.

CADnet supports IFC-based BIM workflows, helping information move between BIM-oriented project teams and the CAD environment used for surveying or construction preparation.

Export Carlson surface information for BIM workflows

The workflow can also move in the other direction. CADnet includes functionality for exporting Carlson surface information for use in BIM-oriented projects.

For civil and surveying teams, this can help communicate terrain or site information to architects, structural designers and other project partners working with BIM. A surface prepared from survey or design data can therefore become part of a wider coordinated project model rather than remaining isolated in a separate CAD drawing.

Useful when the original DWG is unavailable

The strongest use case for CADnet is often a simple one: the drawing you need exists, but not in an editable format. A contractor may receive only a PDF tender set, a survey company may need information from a scanned historic plan, or an engineer may need to recover geometry from archived project documents.

CADnet gives these users tools to convert the source material into geometry that can be measured, edited and passed into normal CAD workflows. This can reduce repetitive drafting and provides more control over how legacy or client-supplied information is incorporated into a new project.

Practical applications for surveyors

Surveyors can use Carlson CADnet to recover useful design and reference information from plans before going into the field or while preparing a final drawing. Existing points, contours, boundaries or alignment information can be digitised and combined with newly collected GNSS or total station measurements.

It can also help when comparing an older design or record drawing with current field data. Rather than working from an image alone, important information from the historic plan can be converted into standard drawing entities and overlaid with the new survey.

Practical applications for construction professionals

Construction estimators and data-preparation teams often receive drawings from multiple consultants in different formats. CADnet provides a common conversion step before that data is used for earthwork estimating, site layout or machine-control preparation.

For example, proposed contours shown only on a tender PDF can be digitised into CAD geometry. Areas representing pavement or other materials can be traced for further quantity work, while building and site information from BIM can be brought into the drawing for coordination with civil data.

Practical applications for civil engineers and CAD technicians

Civil engineers and CAD technicians can use CADnet for document conversion, drawing reconstruction and coordination between CAD and BIM environments. This is particularly useful on refurbishment, redevelopment and infrastructure projects where historical information may exist in several generations of file formats.

Instead of treating every non-CAD document as a static reference, the important content can be selectively converted into standard drawing information and then cleaned, edited and incorporated into the current design.

Runs with IntelliCAD or AutoCAD

Carlson CADnet is part of Carlson’s CAD-based office software environment. The current Carlson 2026 installation supports CADnet and can operate with the included IntelliCAD platform or with a supported full AutoCAD installation.

This gives companies flexibility in how they deploy the software. A business that does not already use AutoCAD can work with the included IntelliCAD environment, while organisations with an established AutoCAD workflow can use CADnet with their supported installation.

Standalone module and wider Carlson workflow

CADnet can be used as a focused conversion and digitising module, but its value also extends into the wider Carlson software environment. It forms part of the Carlson Takeoff Suite alongside Carlson Construction, Trench and GeoTech, and it is also an eligible module within Carlson Select Suite.

For companies already using Carlson Survey, Civil, Construction or other office products, converted information can therefore continue into established surveying, engineering or estimating workflows rather than being exported and rebuilt in an unrelated system.

Who uses Carlson CADnet?

Carlson CADnet is suited to land surveyors, construction estimators, civil engineers, CAD technicians, contractors and other professionals who regularly receive project information in PDF, raster, paper-plan or BIM formats. It is particularly relevant where converting existing documents into editable project data is a regular part of office preparation.

A survey company may use it to recover information from historic plans, an estimator to build usable CAD geometry from tender drawings, and a civil engineering team to exchange information between CAD and BIM-based project workflows.

Carlson CADnet from Global GPS Systems

Global GPS Systems can help determine whether Carlson CADnet is sufficient as a standalone conversion tool or whether it should form part of a wider Carlson workflow for surveying, civil design or construction estimating.

This is particularly useful when your projects combine GNSS or total station survey data with PDFs, scanned drawings, BIM information and existing CAD files. Matching the software modules to the actual files and deliverables used by your team can avoid paying for functions that are not required while keeping the workflow ready for future projects.