Architectural Drawing: Scaling & Materials

Freehand drawings, paintings or sketches - These are good for recording the general visual effect of a building or for making personal statements about how you feel about a place. They can be of any size and in any medium you like.

These are useful for preliminary drawings, for recording measurements as you carry out a survey, or for planning furniture layouts in rooms or buildings which have straight lines. Curves or complicated shapes are difficult to manage. Drawings on graph paper are not suitable for display purposes because the squares make it difficult to "see" the actual drawing.

If you want to make an accurate drawing, show interesting details or the colours or textures of materials on a scale drawing, use plain paper. In this case, you will have to use drawing equipment (below) to make your drawing.

To make scale drawings on plain paper, you will need:

Choose a material which lets you fix your drawing in place with drawing pins or masking tape. It must be smooth and have straight edges which are exactly parallel.

T-square This is used for drawing horizontal lines which are absolutely level.

15 cm size 45" and 30-60" set-squares - These are used for drawing vertical and inclined lines. You could use a protractor to do this, but it is slower and more prone to move suddenly with a slight movement of hand. Adjustable set-squares let you choose any angle you want, but they are expensive. The small set-squares found in most sets of mathematical instruments are too small for architectural drawings.

Scale This looks like a ruler, but the divisions marked on it are in various standard proportions to actual distances - 1:10, 1:20, 1:50, 1:100 etc.

Well-sharpened pencils 2H lead pencils are good for scale drawings. They make a clean, sharp line and don't smudge easily.

A compass is sometimes useful, but most drawings can be made without one.

Drawing pins or masking tape Use these to hold your drawing in place while you work.

If the equipment listed above is unavailable in the school, you can still make scale drawings which are suitable for display by using tracing paper overlaid on graph paper. Tape the tracing paper to the graph paper and tape the two to the table-top to prevent them from slipping about. If the drawing has to be moved before it is complete, do not detach the tracing paper from the graph paper - it will be almost impossible to re-position it accurately.

The kind of paper you need depends on the purpose of the drawing. Preparing a set of scale drawings from the measurements taken on a survey is not always easy, particularly if it is a large or complicated building. It may take several tries to get it right. If you use cartridge paper, you will have to do a lot of rubbing out and re-drawing, so you can end up with a messy looking sheet. Tracing paper makes it easier. Lay a clean sheet of tracing paper over your first drawing. Trace the bits you think are correct, and then work on the next piece of the puzzle. Repeat these processes until you are satisfied that the whole building is correctly drawn. For this kind of rough work, it may be cheaper to buy a roll of detail paper. A 25-metre roll of A1 size costs about S12.00. If you want to display a drawing made on tracing paper, pin it up with a sheet of white paper behind it. You can colour tracing paper with pastels or coloured pencils, but put the colour on the back of the sheet. It will show through gently on the front and can be applied or removed without messing up the lines drawn on the right side. Don't paint on tracing paper; it goes bubbly. For painting, use a sheet of suitable cartridge paper - one that hasn't had too much rubbing out and re-drawing done on it. If your drawing is complicated, do all your preparatory work on tracing or detail paper. Then, when you are sure that you have it all worked out, make a fresh drawing on the cartridge paper.

Drawing to scale Except when showing very small details, architectural drawings do not represent objects at their full size. Buildings are drawn much smaller than their true size, but with all the parts in the correct proportion to each other, just as in the real building. This is called drawing to scale.

The bigger the object or area really is, the smaller the scale of the drawing has to be. Otherwise, it would not fit on one sheet of paper. For example, the drawing of a single house might be at a scale of 1:50. This means that 1 unit on the drawing equals 50 units on the real building. If you want to draw a plan showing all of the houses in an estate, you might choose a scale of 1:200. The plan of an entire neighborhood might be at the even smaller scale of 1:1000. If you wanted to show how certain pieces of the building were constructed, you might make a detail drawing of that part at 1:10 or even 1:5. To make a drawing to scale, you need the actual measurements of the object and a scale rule (see Drawing equipment, above) or graph paper which you have marked off to the scale you want. Using a scale rule Suppose you want to draw a 1:50 plan of a room that is 5 metres long by 3.5 metres wide.

Take your scale rule and select the side marked 1:50. Then, use the numbers on the scale to measure out a rectangle 5 by 3.5.

When you do a scale drawing, it is as though you were looking at the building from a distance. This makes the building look smaller than it really is. This imaginary distance also affects colours and textures. If you look at a building from a distance, you may not be able to make out the joints between the brickwork, and where one rooftile ends and the next begins. The door handle and the letter box may just be dark shapes on the front door. Something similar happens to colours. The farther away you move the mistier or greyish they become, like mountains viewed from a distance, or houses and fields seen from a plane. The amount and sharpness of detail you show, and the brightness of colours on the drawings, depend on the scale of the drawing. You cannot show a lot of detail on small-scale drawings. Bright colours which might look fine on a 1:50 elevation of a house may look garish if they are used for the same house shown at a scale of 1:200