Understanding the concept of architectural Scales
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Scale drawings allow us to accurately represent sites, spaces, buildings and details to a smaller or more practical size than the original.
When a drawing is described as ‘to scale’, it means that each element in that drawing is in the same proportion, related to the real or proposed thing – it is smaller or indeed larger by a particular percentage.
If something is ‘drawn to scale’ we expect that it has been drawn, or printed, to a common scale that is used as standard in the construction industry. As we gain a better understanding of scale, we can view a drawing in a particular scale and instantly recognise and understand the spaces, zones and gain a quick understanding of the existing or proposed spatial relationships.
In the real world, one meter is equal to one meter. A drawing at a scale of 1:10 means that the object is 10 times smaller than in real life scale 1:1. You could also say, 1 unit in the drawing is equal to 10 units in real life.
As the numbers in the scale get bigger, i.e. 1:50 – 1:200, the elements in the drawing actually get smaller. This is because in a drawing at 1:50 there is 1 unit for every 50 unit in real life. A drawing of 1:200 is representing 200 units for every one unit – and therefore is showing the elements smaller than the 1:50 drawing.
It is worth noting that scale drawings represent the same units. So, if a drawing is at 1:50 in cm, 1cm in the drawing will be equal to 50cm in real life. Similarly, if a drawing is in mm, at 1:200 – one mm unit in the drawing will represent 200mm in real life.
Working with scales for architectural representation
In architecture, we use a collection of standard scales to represent our designs. For example, it is common practice to produce floor plans at a scale of 1:100 (dependent on size of project and paper). Once you gain an understanding of scales, it is easy to understand which scale is most suited to which type of drawing.
The general requirement of a scaled drawing is to convey the relevant information clearly with the required level of detail. If you are working in practice there will often be office standards. For example, they may only use layout sheets of either A3 or A1 – depending on the scale of the project and information that is being represented. As a student, you need to make these decisions based on industry standard. It is always best to use a ’round’ scale, i.e., one of the scales mentioned below, and not make up your own.
The following looks at the recommended scales for architectural use in the metric system. The chosen scale and paper size will often depend on the size of site/design of each individual project.
Site and Key Plans
Sketch schemes etc
Location / Plan drawings
Component / detail drawings
Working out the scale
A scale is shown as a ratio, for example 1:100. A drawing at a scale of 1:100 means that the object is 100 times smaller than in real life scale 1:1. You could also say, 1 unit in the drawing is equal to 100 units in real life.
So, if we were drawing a table that measured 100cm wide by 200cm long, at a scale of 1:50, you would draw the table 2cm wide by 4cm long on your piece of paper. This is worked out by dividing the real life size (100cm) by 50 (1:50 scale). This gives you a result of 2cm. For the length of the table we divide 200cm by 50 to get a result of 4cm.
Of course, it is not necessary to calculate the required measurements when you draw. You can either use a scale ruler to hand draw your plans, or software such as Revit, AutoCAD, ArchiCAD that will allow you to present your drawings at any scale and easily switch between scales as required.
How to use a scale ruler
A scale ruler is a tool that architects, engineers and designers use to draw their designs at an appropriate scale that it fits on a piece of paper and is in proportion to accurately convey the scheme. The scale ruler comes in different shapes, flat or triangular but they all provide sets
of graduated numbered spaces, that establishes a proportion of one unit to the specified unit, i.e. different scales. As an example, the ruler I have in front of me now has the following scales; 1:1, 1:100, 1:20, 1:200, 1:5, 1:500, 1:1250, 1:2500.
Scale rules have varying number of scales on them, depending on their intended use. Using a scale rule is pretty easy when you know how.
When you are drawing a plan, you select the scale you intend to use by turn the ruler to the appropriate side. You can then draw the line to the desired measurement using the scale ruler. For example, if you have select to draw a 5m wall at 1:100, you would select your 1:100 side of the ruler, and draw 5 units along the ruler, as each unit represents 1m.
When you are reading plans, you establish the scale of the drawing or plans, and select that scale on your ruler, you are then able to measure the lines using the correct scale.
Working with scales digitally
You can download a handy pdf of this post by clicking the download button below!
I have a question, about scaling. I have a 2D site drawing drawing 1:1. The site drawing is referenced on my cover sheet. The cover sheet is set to print at 1/4″ = 1′ but I want the scale of the site plan to be 1″ = 30′. I can’t figure out what the one scale factor is that I can use to scale the 1:1 drawing by to get it to come in to the cover sheet at the right scale.