Last edited 20 Jun 2019

Construction drawing

Construction drawing is the general term used for drawings that form part of the production information that is incorporated into tender documentation and then the contract documents for the construction works. This means they have legal significance and form part of the agreement between the employer and the contractor.

The main purpose of construction drawings is to provide a graphic representation of what is to be built. Construction drawings should be concise and coordinated to avoid, wherever possible, ambiguity and confusion. Delays and misunderstandings can be minimised by properly coordinating the drawings. For more information, see Document control.

Specifications will detail the materials, standards, techniques, and so on required to carry out the works. Construction drawings provide the graphical representation, indicating the arrangement of components, detailing, dimensions and so on. They may sometimes contain some of the information set out in specifications, but this should be avoided if possible, by referring to specifications rather than duplicating information. Where there is crossover, care must be taken to ensure proper co-ordination so there is no confusion. If there is disparity between the two, the specifications will tend to take precedence over the drawings.

Construction drawings are generally drawn to scale, either in an elevation, plan or section view. They adopt a set of standard architectural hatchings and symbols that allow anyone familiar with them to decipher and interpret them.

A complete set of construction drawings tends to comprise floor plans, elevations, sections and detail drawings, that together provide a complete representation of the building. On many projects, each major trade will have separate trade drawings, e.g. electrical, plumbing and so on.

Construction drawings may be prepared by hand, but it is more common for them to be prepared using computer aided design (CAD) (or computer aided drafting) software.

More recently, the use of Building Information Modelling (software) has allowed the creation of a 1:1 virtual construction model (VCM), containing information allowing all objects in the model to be manufactured, installed or constructed.