Week Three Lecture: Orthographic Projection/Drawing Plans
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It is a necessity that you read and follow all instructions throughout the Lecture. Lectures are designed with interactivity, to aid in the learning process. Often times the lectures will include tips for properly completing assignments. Be sure to read all information, view all aud/vid files and complete all practicals associated with each lecture.

Overview
Orthographic Projection
Drawing Floor Plans, Doors, and Windows
Dimensions
Recap

Overview

In Week Two's drawing assignment I told you that it is best to use our tools more then our scales when measuring. Orthographic Projection is another good example of this theory. Orthographic projection is a drawing method used for drawing plan/section/elevation drawings. This method uses right angles, parallel lines and perpendicular drawing surfaces.

I think of Orthographic Projection drawings as solving puzzles. We start with the plan and an elevation and we are able to figure out what the side looks like.

Orthographic Projection

Below you can see an oblique drawing of a building block. We are going to use this drawing and dimensions to draw the top view, front view and side view of the block. Let's get started on Assignment 3A. See "Assignments" link under Week Three on the course "Classroom" page, for detailed assignment instructions.

(Insert Block1)

Assignment 3A Tips:
Set up your sheet of paper on your drawing surface. The paper should be horizontal on the drawing surface. Tape the paper down. In order to get all of the drawings on the sheet we need to determine the layout of the sheet before we draw a single line. The top view should go in the upper left quadrant of the sheet, so that is where we started working. Remember we are drawing at Full Scale. Think about which scale you will use for this exercise. I would use the one marked 16 because this gives me 1" marks.

Now that we have a plan for the scale we will use and how we will layout the sheet, we are ready to draw. Use your 3H drafting lead to draw the Top View very lightly. Place your scale along the top edge of the t-square or parallel rule and mark the 0 point, the 2" point and the 3" point. Draw the 3" line across the top first. Then at each of the marks you made draw a line down. Next, you can either use your 45 degree triangle or your scale to find the bottom edge of the block. Draw a light horizontal line. Ok, the Top View is done.

Click here to view

The next drawing is the front elevation, which we will project from the top view. First we will draw a light line where we assume the groundline is. Once again this requires planning ahead. We want to leave enough room for the title block at the bottom. Think about where to put the groundline. Once we have established the ground we will project vertical lines down from the top view these will be used for the edges of the block. Now we will have to use our scale to measure the heights of the block segments. Mark off the 1" for each step and draw the horizontal line lightly.

Click here to view

The next drawing is the side elevation which is a little trickier then the front elevation. We want to draw the side elevation to the right of the front elevation. The problem is that in order to project the lines for the sides of the block just like we did for the front elevation we are going to have to turn the side elevation so that it ends up next to the front elevation. In Ching's book there is an example of this on page . We are going to use that same approach. First we draw the ground line over from the front elevation. Then project the horizontal lines from the front and back of the block. These lines will end up being the sides of the side elevation. This requires us to turn the side elevation and we'll do that with a 45 degree line. Draw the line from the top horizontal line to the bottom line. Where the diagonal line crosses the horizontal line project down your vertical lines.

Click here to view

We are getting close to having our side elevation. We are missing the horizontal lines for the steps. We can draw these easily by projecting the lines from the front elevation.

Click here to view

Let's finish this drawing up. The finished drawing of the block should have the correct line weights and show the light guidelines that you used to construct the drawing.

The rule for lineweights in Two Dimensional (2D) drawings:
In 2 dimensional drawings (plans, sections and elevations) -whatever is closest to you is the thickest line. There are only 2 lineweights in this drawing so you can use a thick and a medium line or a medium and a thin line.

Put your drawing titles and scale indication under each drawing. Put your sheet title at the bottom. The finished drawing should look like this:

(Insert Assign3A)

Have Questions?
If you have questions regarding any of the material covered in this section, visit the "Week Three: Orthographic Projection" Discussion Forum. The forum can be accessed by clicking on the "Activate Course WebCT Account" link located on the course "Classroom" page. Once inside WebCT's discussion board, post questions and/or comments under the appropriate forum.

Now that Assignment 3A is done try your hand at Assignment 3B. Hint: The assignment sheet shows the Top View and the Rear Elevation. Assignment 3B is looking for the Top View, the Front Elevation and Side Elevation. Assignment 3B focusses on Orthographic Projection drawing skills. See "Assignments" link under Week Three on the course "Classroom" page, for detailed assignment instructions.

Drawing Floor Plans, Doors, and Windows

This section of the lecture covers drawing floor plans and adding doors and windows. Then, in Assignment 3D we will add the dimensions to the drawing. Print out Assignment 3C—see "Assignments" link under Week Three on the course "Classroom" page, for detailed assignment instructions. . It is a drawing of a small office. It is drawn at 3/8" scale but I want you to draw it at ¼" scale. Note: Your office plan will be smaller then the office plan shown in the assignment. From Week 2 you know how to draw the plan of the office.

Just to review:

• Lightly draw the outline of the office first.
• Locate and lightly mark the door and window openings.
• Check to see if your drawing looks like this with very light lines.
  

(Insert Office plan 1)

Now that we have the walls and openings drawn we need to add the windows. Look at page 26 in the Ching book. It shows examples of doors and windows in plan.

Assignment 3C Tips:
Lets begin with drawing the windows. At ¼" scale or smaller we will draw the windows as a single line. The line should be exactly in the middle of the wall. That means if the wall is 9" thick we need to measure in 4 ½" from the edge of the wall and place a mark.

(Insert office1)

Now draw a vertical line using your triangle against your T-square to show the window glass.

(Insert office2)

Next draw the door and the door swing. The door swing show which way the door opens and the path that it follows as it opens. This lets the designer know if the door will bump into fixtures or furniture when it is opened. It also tells the carpenter how to hinge the door. Let's get back to drawing the door. You want to show the thickness of the door. The standard door thickness is 1 ¾". It is difficult to measure 1 ¾" at ¼" scale so just use 2" thickness at ¼" scale. First draw the edge of the door closest to the door jamb (the frame for the door opening). Since it is a 3"-0" opening we will draw the door at 3'-0". Then measure down 2" and draw the other edge of the door. Draw in the ends of the door.

Now it is time for the door swing and to use your circle template. The door swing is a quarter circle. We will use the circle template to draw a quarter circle. As you look at the circle template you are probably wondering which circle to use. We can find the correct circle in two ways. We can try different circles until we find the one that fits or we can figure it out with a little math:

• The door is 3'-0" wide. Thus the door swing has a 3'-0" radius.
• The scale of the drawing is ¼" = 1'-0". So each ¼" is a foot.
• A ¾" radius = 3'-0" in scale.
• The circle template gives the circle sizes in diameter. The diameter is twice the radius. 2 (3/4) = 1 ½.
• Use the 1 ½´ diameter circle on your circle template.

If you are not too confused by that, just take your circle template and find the 1 ½" circle and draw your door swing.

Now that we have the plan drawn lets finish up this drawing. Go over the lines to show the correct line weight. Remember that in 2D drawings the lines closest to you are the thickest. Think about what lines are nearest to you when you look at this plan. The walls and glass for the window will be your thick lines. The door will be medium lines because the two lines are close together and can't be drawn as thick lines. The door swing and the window sills are thin lines.

That finishes Assignment 3C1. We will use this same drawing in Assignment 3C2. In the end you will turn in only Assignment 3C which is this floor plan with dimensions.

Have Questions?
If you have questions regarding any of the material covered in this section, visit the "Week Three: Drawing Floor Plans, Doors, and Windows" Discussion Forum. The forum can be accessed by clicking on the "Activate Course WebCT Account" link located on the course "Classroom" page. Once inside WebCT's discussion board, post questions and/or comments under the appropriate forum.

Dimensions

You will need to know the following terms, regarding dimensions: (full definitions are available via the "Terms" link on the course "Classroom" page)

Dimensions should tell enough information so that the person constructing the building is not expected to make any assumptions about the length, height, depth, angle or location of an element (ie. wall, door, window etc.). Dimensions are shown to give the size or location of an element. Size dimensions tell the length, depth or height of an element. Location dimensions tell the position of an object in relation to an established point or object.

Accurate dimensions are very important. Dimensions are the ruling number. It doesn't matter how long you draw a wall since that wall will be built according to the dimensions on the Construction Drawings not according to how you drew it. In the end, if the you gave the contractor the wrong dimension and the wall is built according to that dimension then you are responsible for the mistake.

In order to really explain dimensions let's look back at the plan we drew in Assignment 2D Assignment 2D was the floor plan of a garden shed. (see Week Two "Assignments" link on the course Classroom page].

Looking at Assignment 2D we can see that I have added a few notes to explain how we draw dimensions.

(Insert Assignment2D1)

Notice:

• There is a small gap between the dimension extension and the actual plan drawing.
• The dimension text is 1/8" high and floats above the dimension line. Be sure to use guidelines and your architectural lettering.
• The dimension line and the dimension extension lines are drawn as thin lines.
• The architectural tick mark is drawn free hand at a 45 degree angle as a thick line.
• Always give your dimensions in terms of feet and inches except if it is leass then 1 foot then use only inches.

  Assignment 3C2 Tip:
  Ok, for Assignment 3C2 finish the office plan by adding your dimensions. Do the dimensions so that they look like the ones that I gave you with the assignment. See Week Three "Assignments" link on the course "Classroom page" for specific instructions on completeing Assignment 3C.Use Assignment 3C1 to complete the assignment. Be sure to add the title and the course information to the drawing. Now you are

  Have Questions?
  If you have questions regarding any of the material covered in this section, visit the "Week Three: Dimensions" Discussion Forum. The forum can be accessed by clicking on the "Activate Course WebCT Account" link located on the course "Classroom" page. Once inside WebCT's discussion board, post questions and/or comments under the appropriate forum.

Recap
This week we have covered a lot of material - Orthographic Projection, drawing and dimensioning floor plans plus adding windows and doors. Practice these skills and get ready for the Midterm next week. We will cover the following materials in the Midterm:

Lettering
Linework
Scale
Drawing Plans with doors and windows.
Dimensioning
Orthographic Projection

See Mid-Term exam link on the course "Classroom" page for more information on taking the Mid-Term exam. See course "Schedule" for testing due dates.