For architectural design projects, while there is the emphasis on using 3D models and architectural BIM modeling, the time-tested practice of using architectural drafting and 2D technical drawings is still commonplace in the AEC industry. Architectural drafting has evolved from the drawing board to computer-aided design and drafting (CAD) software programs. Drafting practices help to provide architectural construction drawings that include the technical details of architectural, structural and electrical elements required for the construction of a building. To understand the stage at which architectural drafting takes place, the workflow of a building design lifecycle must be considered.
The basic workflow of an architectural design project starts with the architect creating a conceptual plan which is usually modelled into architectural 3D models and rendered as photorealistic images for marketing and presentation to clients and customers.
Once the conceptual design is approved by the client, the design is then progressed into more detail and shared with other parties such as structural and MEP engineers. The way in which the design is progressed for the ‘design development' phase by an architect lends itself to two options, either to develop a 3D model with more detail and then create subsequent sheets and details using a 3D tool such as Revit or AutoCAD, or as is still commonplace, to develop the concept design in 2D using more traditional methods. From the conceptual plans provided by architects and engineers, a drafter can convert these designs using CAD software programs to create technical drawings.
Architectural drafting is the process of creating technical drawings which include the floor plan, sections, elevations, detailed drawings and other documents in a construction drawing set (CD Set), which are typically required for the construction of a building.
The difference between Architectural Drafting and Modelling
Architectural drafting refers to creating 2D technical drawings and architectural construction drawings which are mainly used by contractors and consultants on site. Architectural 3D modelling refers to creating 3D models and renders of photorealistic images which are mainly used to present the architectural design for marketing purposes and then progressed from there to create the 2D technical drawings, in effect feeling like an extra stage (the 3D modelling element). The main software used for drafting, to create 2D technical drawings is AutoCAD while modellers use Revit and ArchiCAD to create 3D models and rendered images. Architectural draftsmen need to have basic 2D and 3D software knowledge such as AutoCAD and knowledge of technical codes and drafting guidelines specified by organisations such as American National Standards Institute (ANSI), American Society of Mechanical Engineers (ASME), American Design Drafting Association (ADDA), Public Works Government Services Canada (PWGSC), National Institute of Building Sciences (NIBS), BSI British Standards Institute and Standards Australia Code AS1100. Architectural modellers need to have a deeper understanding of architectural, building and construction concepts and experience with 3D software programs such as Revit and ArchiCAD.
Why Architectural Drafting is still Common in Architectural Design Practices
Architectural 3D models are preferred by architects and designers because they provide a 3D perspective of the conceptual plan of the building; it makes management of project data easier and allows for design changes on the go. However, construction companies that require technical specifications of the architectural project prefer 2D technical drawings and architectural construction drawings because they provide accurate details required for construction, most of the resources involved in construction understand 2D drawings, there are no issues with compatibility of software as compared to when using 3D models and it is a suitable solution to meet the budgetary requirements of a construction project. Some of the reasons why architectural drafting is preferable by several construction companies include:
• Suitable as per construction requirements – In some building projects, 2D technical drawings or architectural CAD drawings are sufficient to complete construction, where additional information that 3D models provide is not required. A construction drawing set (CD set) includes all the floor plans, elevations, sections and detailed drawings required for construction. Technical codes, symbols and other additional information such as the type of material are provided in technical drawings. Therefore, construction companies find 2D technical drawings sufficient to successfully complete construction.
• Availability of technical resources – Not all companies have technical resources to deliver 3D models. While drafting teams are qualified to work on AutoCAD to deliver 2D technical drawings, they may not be qualified to work on Revit to deliver 3D models. In the construction industry, the availability of drafting teams who can provide 2D technical drawings is ample compared to companies that provide 3D modelling services.
• Availability of software – The adoption of new software and practices is gradual and slow in the construction industry. The software used in building projects varies from country to country. Some countries use ArchiCAD and AutoCAD Architecture instead of Revit, therefore leading to the incompatibility of project data. 2D technical drawings in AutoCAD are widely used and compatible making it a preferred option to Revit 3D models.
• Suitable as per cost and budgetary requirements – In most cases, construction companies do not find the need to invest more in 3D models, when drafting solutions provide detailed technical drawings which are sufficient and relevant enough for construction. There is also the added investment in resources that are competent enough to understand and implement architectural 3d models on-site.
While architectural 3D modelling and BIM modelling provide design-related information typically required for architects and designers in the design stage of the building project lifecycle, architectural drafting provides technical drawings that are not just about aesthetics but about high-performance detailing of construction elements. Architectural CAD drawings specifically communicate the design intent and help in the construction of buildings which companies find relevantly sufficient over 3D models. Even as construction companies will need to eventually evolve to combining the use of 2D technical drawings and architectural 3D models until then, the time-tested practice of using architectural drafting and drawing solutions in construction is here to stay.