Difference between Working drawing and Construction drawing


Construction Drawings:

Construction Drawings are Architectural Construction Documents (CD sets) also known as working drawings are prepared to envision the architectural elements in the building or the building before construction starts. Are a set of drawings used to show the relationship between different parts of the project. In construction, they will show all axes of columns, overall dimensions, and dimensions required to relate/assemble parts together or in locations like the distance between walls, components, and openings. They are produced by consultants.


They can be known as well as execution or installation drawings. They are used on-site to build from scratch a building or to check what was built (for inspection). Those drawings need to be reviewed with time and by end of the project to produce the As-built drawings if there are some deviations from the main intended drawings. Construction drawings have all the necessary views and sections to show everything in place and how they are related. They include mechanical drawings, electrical drawings, plumbing, construction, and steel structure drawings.


They are also called assembly drawings for manufactured components. They are preliminary assembly designs and detailed assembly designs. Preliminary is used for tenders to show the main dimensions and specs required without going into details between parts. Detailed assembly is used for assembly during the installation or assembly process.


All specs of materials, assembly order notes, required torques, ways of assembly, and transportation can be shown in the notes. Main BOM (Bill Of Materials) referring to all main components or parts of the project is a crucial part of the installation drawings.


Working Drawings:

Traditionally, working drawings consist of two-dimensional orthogonal projections of the building or component they are describing, such as plans, sections and elevations. These may be drawn to scale by hand, or prepared using Computer Aided Design (CAD) software.


They are the very detailed drawings of components and assemblies referred to in the construction drawings. They are produced by contractors or manufacturers. They are mainly fabricated and assembled parts. Those drawings are very detailed in dimensions with finishing, tolerances, and referral to other detailed drawings (if needed). All specs of materials and standards to be followed have to be indicated in the notes and tables.


For manufacturing, there are 2 types of working drawings: Detail drawings and Assembly drawings. Assembly drawings have all components that will be assembled at the manufacturer's site or a construction site and referral to bought parts/off-shelf parts as well as manufactured parts, with quantities, specs, and standards for each in a detailed table (BOM). Assembly drawing can be 3D exploded and/or 2 to 3 assembled closed views with sections showing all main dimensions relating parts together, with interference fit if present. Other detailed views can be used if components are not clear in their original views. Steps of assembly are mentioned in the notes.


Detail drawings are mainly for manufactured parts and they were referred to in BOM of assembly drawings. All dimensions are necessary for manufacturing without repetition. Tolerances and surface finish have to be identified for each part and all critical dimensions as possible. Any missing detail can stop production.

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