Interpreting Drawings, Cutting Lists and Costs

Reading the plans before you build

Before any building work starts, someone has to read the drawings and work out exactly what materials the job needs and what they will cost. A construction drawing is a scaled picture of a building or part of it, and there are different kinds: a plan view looks straight down on the layout, an elevation shows one side from outside, and a section shows a cut-through of the inside. Because a drawing is shrunk to a scale, you use that scale to find the true sizes. From those sizes you write a cutting list of every part and its measurements, and from the cutting list you work out the cost. This module shows how to interpret each kind of drawing and turn it into an accurate list of parts and a price.

Drawing words

Learn these five terms before you read a drawing and cost a job.

Match each drawing item to what it shows

A plan against an elevation

Two everyday drawings show a building in two very different ways.

What does the scale tell you?

A drawing is at a scale of one to fifty. A wall is drawn forty millimetres long. What does the scale tell you about the real wall?

• The real wall is fifty times longer than on the drawing
• The real wall is forty millimetres long
• The drawing is life-size
• The scale makes no difference to the measurement

From drawing to cutting list to cost

A drawing on its own does not buy any materials; you have to turn it into numbers. First you read the dimensions off the drawing and use the scale to find the true sizes. Next you write a cutting list, which sets down every part the job needs, its size, and how many of it. Finally you turn that list into money: you multiply the number of each part by its price and add the results to reach a total. Doing this carefully on paper, before anything is cut, is what stops a job running short of material or over budget. When you are asked to cost a task, always work drawing, then list, then price, in that order.

Pick the true facts about drawings

Select every statement about construction drawings that is true.

• A plan view shows the layout from above
• A scale tells you how much a drawing is shrunk from real size
• A cutting list gives the parts and sizes needed
• An elevation shows the layout from directly above
• Cost is worked out by ignoring the quantities

Order how to cost a job from a drawing

Put the steps of costing a job from a drawing in the correct order.

• Read the dimensions off the drawing
• Work out the true sizes using the scale
• Write a cutting list of the parts needed
• Multiply each quantity by its price
• Add the prices to reach the total cost

Complete the drawing facts

A drawing seen from directly above is a _____ view. How much a drawing is shrunk from real size is its _____. A list of the parts and sizes needed is a _____ list. Multiplying the quantities by their prices gives the _____.

Building flat-pack furniture

Think of putting together a flat-pack bookcase. Before you touch a single screw, you unfold the instruction sheet. It shows the finished bookcase from different sides so you can picture it, it labels every panel with its size, and it lists exactly how many screws and shelves are in the box. If a part is missing or the wrong size, you find that out from the sheet, not halfway through the build. Reading a building drawing is the same job on a bigger scale. The drawing tells you what goes where and how big each piece is, and from it you can write down every part you need and add up what it will all come to, long before any timber is ever cut. The paperwork done well is what makes the building go smoothly.

Tap the parts of a cutting list

Tap every item below that a cutting list should include.

• the name of each part
• the size of each part
• how many of each are needed
• the colour of the delivery van

Work out the total cost

A cutting list needs six lengths of timber, and each length costs five pounds. What is the total cost in pounds?

Read the drawing right

Read each situation and choose the best answer.

• A drawing is at a scale of one to fifty. How do you find a real length from a length on the drawing?
• You need to know how much material to buy for a task. What should you prepare first?
• You want the total cost of the materials. What do you do?

Build a drawing point

Choose the word for each gap to complete one accurate point about reading drawings.

Explain interpreting drawings and costing

A friend has to read a building drawing and work out what the materials will cost, but does not know where to start. Explain clearly how to interpret a drawing and cost a job.

• Explain the main types of drawing, such as a plan and an elevation
• Explain what a scale is and how to use it to find real sizes
• Explain what a cutting list is
• Explain how to work out the cost from a cutting list
• Explain why reading the drawing carefully first saves mistakes