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Construction Drawings

Building drawing types and their purposes.

Updated

A site layout. PHOTO/COURTESY

Drawings of buildings, also known as construction drawings or architectural drawings, are visual illustrations that depict a proposed public, residential or commercial building.

They guide the construction process by showing a building’s dimensions, how various materials will be used as well as other aspects that also help local authorities to grant necessary approvals.

Construction drawings are often drawn by architects, although other building professionals contribute one or several drawing types. For instance, on a shopping mall project, engineers may draw their own drawings for plumbing or ventilation.

Drawings of buildings have architectural symbols for various facets of the construction project. These symbols include standardized markings that represent lighting and electrical structures among other features.

Architectural symbols make it easier for construction teams and local building authorities to read and understand construction drawings.

Here are the common types of architectural drawings:

Building drawing types

There are five main types of construction drawings, including architectural, electrical, plumbing and finishing drawings – each serving a specific purpose.

1. Architectural drawing

This drawing, which has the particulars of the project, is labelled as the mother drawing of all the drawings used in the construction field.

Common types of architectural drawings include site plan, working plan, section drawing, elevation drawings, and detail drawings.

(i.) Site plan: Defined as a large-scale drawing indicating the full scope of the site for a project, a site plan is the primary drawing used for marking out the design on site.

This building drawing is often completed after a series of office meetings and construction site inspection.

(ii.) Working plan: This type of drawing provides the details of horizontal measurements of the building, thickness of walls, empty spaces within the building, as well as the locations of columns.

A working drawing also illustrates the openings of a building including doors, windows, and ventilators. Traditional work plans contain two-dimensional orthographic projections of a structure such as sections and elevations.

(iii.) Section drawing: These are drawings of buildings in perspective. In other words, these are images of a building cut through an imaginary vertical plane.

Perspective drawings of buildings give a view through the spaces and surrounding components of a building – which may not be obvious on working drawings.

Section plan drawings are often used to show the foundation of a building, the inside of walls or floors, beams, columns, lintels (support structures above doors and windows), etc.

Section drawing.

(iv.) Elevation drawing: This is a first angle projection that indicates all the parts of the structure as viewed from a specific direction with the perspective flattened.

These drawing types are usually made for four directional views, for instance, north, south, east, and west. They provide details of openings, dimension and form of external surface, height of building and last finish of the building.

(v.) Detail drawing: This building drawing illustrates elements shown in other drawings of buildings on a bigger scale. They provide more detailed information regarding the placement and connections between various parts.

Detail drawings can be created for staircases, door frames, window frames, cornices, or material connections – e.g., where a column meets the foundation.

2. Structural drawing

This is a type of building drawing with all data on how a structure will be assembled. Structural drawings, which are the backbone drawings of buildings, are prepared by engineers based on details provided by architectural drawings.

Editor’s Note: Structural drawings should not be confused with architectural drawings. While structural drawings are easily identified from their mostly line work drawings, architectural drawings contain features such as bathroom and kitchen fixtures.

(i.) General notes: This is not a drawing but a text document that provides details of all the structural drawings mentioned in this section such as concrete mix, lapping interval, curing period, abbreviation, codes and other important construction processes.

(ii.) Excavation drawing: These types of construction drawings represent the length, width and depth of the excavation at the construction site, column position, footing plan and grid lines of column. The excavation line is usually marked in a dotted line to make it easily identifiable.

Excavation layout.

(iii.) Column layout: This is a drawing that has details of the position and orientation of columns and column reinforcement for the building. This is one of the most important types of building drawings because it is not possible to locate the actual location of the structure without a column layout.

(iv.)  Plinth beam layout: This indicates the sizes, positions, and section of plinth beam and the details of reinforcement in plinth beam (a reinforced concrete beam built between the wall and its foundation).

(v.) Lintel beam layout: This indicates the sizes, position and section of lintel beam and the details of reinforcement in lintel beam (a beam that is built over a door or a window to support the weight above).

(vi.)  Roof beam and shuttering layout: This denotes the details of reinforcement of roof beam, its section and shuttering details.

(vii.) Roof slab layout: This drawing provides details of reinforcement of a roof slab, its section and openings in the roof for stairs or skylight.

RELATED: How to Read Construction Drawings

3. Mechanical and Electrical drawing

Also known as wiring diagram, electrical drawing provides visual representation and information of electrical fixtures, location of switches, fan, light, and other details on electrical system or circuit.

These types of construction drawings are used to deliver the engineering design to the technicians hired to install the electrical system (wiring) for the building.

In small residential projects, the two drawings are combined into one, but professionals may choose to separate the two in large commercial projects such as hospitals that often require complex ventilation systems. 

4. Plumbing and drainage drawing

Plumbing and drainage drawing denotes the system of piping for water or gas supply into the building and the wastewater coming out of the house.

These types of construction drawings show the exact locations and sizes of plumbing fixtures such as pipes, pumps, water tanks, drains and vents.

5. Finishing drawing

These drawing types represent the finishing for every part of the building, including plastering texture, paint colours, flooring design, etc. This information is often provided in elevation drawings.

Unlike detail drawings, which focus on the structural elements of a building, a finishing drawing focuses on the design elements such as wall paint colours, floor patterns, plaster texture, etc.

Other types of drawings include:

Reflected ceiling drawing

This drawing depicts what the ceiling should look like when viewed from the floor. It might show elements such as the light fixtures attached to ceilings, visual features of a cornice, the design of a visible column.

Perspective drawings

These drawings illustrate a proposed building in three dimensions. They offer a more detailed understanding of how the structure will look once finished.

A perspective drawing might help builders visualize, for example, how porches fitted to the outsides of apartment units will look like once erected.

Janet Mutegi holds a degree in Architecture from the University of Nairobi. Her wealth of practical experience from working on major projects across Kenya makes her a valuable asset to our team.