A proportional sketch is the drawing you produce on-site while you're doing the measure-up.

Some installers work with a sheet of blank paper, others use graph paper to help get the proportions right.

Either way, it's best to draw the lines with a pencil and have an eraser on hand so you can correct any mistakes on the spot.

You can see from the above drawing that the symbols and abbreviations used on proportional sketches are much simpler than those used on building plans.

This is because you only need to include the specific information relevant to the flooring installation.

The Just for fun exercise shows some common examples of symbols and abbreviations.

How to draw a proportional sketch

Here are the basic steps involved in drawing up a proportional sketch.

1. Walk around the room and look at its general size and geometry. If any furniture or obstacles are in the way, have a look at the ceiling to get an idea of the room's shape.
   
   
2. Draw an outline of the room, showing its shape and features. Leave some space around the outside of the drawing and position the main entrance at the bottom.
   
   
3. Mark in details such as doors, fireplaces, stairs, wardrobes, projections and recesses.
   
   
4. Take 'running' measurements around the room and write them on the sketch as you go. Put the figures on the inside of the perimeter walls. Do the wall to wall (w/w) measurements first and then the running measurements.
   
   
5. Check the running measurements against the w/w measurements. If they're not within 30 mm of each other, take the measurements again to see where the error is.
   
   
6. Double-check that all necessary details and room features are recorded on the sketch.