Building scales

Introduction

Plans of buildings drawn to scale are commonly used in the building industry.

By using a scale we can draw the whole building on a certain sized piece of paper while still showing all the required details.

Common scales used in building plans include:

1:100
1:200
1:500

Building plans

Measurements on a plan can be in millimetres or metres.

In this example the plan has measurements in metres.

This plan is drawn to a scale of 1:100

This means that in reality things are 100 times larger than they are drawn on the plan.

Image showing the site plan for a house and carport on an allotment.

 

Image showing a house plan without any dimensions written on it.

Building plans

If a plan is drawn to scale, a builder can measure a length on the plan (using a ruler) and use the scale to calculate the actual measurement in the building.

This is particularly useful if there are no lengths written on the plan.

 

Image showing using a ruler to measure a bath off the plan.

Working with a scale

This plan is drawn to a scale of 1:50.

The ruler shows the length of the bath on the plan to be 34 mm.

The actual length of the bath is 50 times longer than this measurement.

50 x 34 mm = 1700 mm or 1.7 metres.

For most adults 1.7 metres is a good length for a bath.

 

Image showing using a ruler to measure a bath off the plan.

Determining length – question 1

On the same plan the width of the front door is 17 mm.

What is its actual length?

Remember the scale of the plan is 1:50.

Type your answer in the box and select submit.

   Submit

 

Image showing using a ruler to measure the width of the deck off the plan.

Determining length – question 2

On the same plan the width of a deck is 80 mm.

What is its actual length?

Remember the scale of the plan is 1:50.

Type your answer in the box and select submit.

   Submit

 

Image showing using a ruler to measure the length of the house off the plan.

Determining length – question 3

On the same plan the total length of the groundfloor is 350 mm.

What is its actual length?

Remember the scale of the plan is 1:50.

Type your answer in the box and select submit.

   Submit

 

Summary

This is the end of the section on building scales.

Key points to remember are:

  • building plans are drawn to scale
  • scales used on building plans include 1:100, 1:200 and 1:500
  • scales on building plans allow you to work out the actual lengths.

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