How to Build a Blueprint

Draw a scaled down floor plan for the house on your computer. A floor plan is a basic blueprint-like rendering that shows the basic shape of the floor and the position of the walls on it. This plan will help you draw your finished blueprint. Use a blueprint drawing software application to make these images since it can be hard to draw to scale for a very small-size image.

Calculate a scale for the blueprints based on the intended size of the house. If you are only building a small house, you can go with a scale as small as 1:4. If you are building a large house, you may have to go with a larger scale (1:8 to 1:16), since small scale plans for such a house may not be manageable. The average American house is about 2,350 square feet, use this as your guideline if you are drafting a blueprint for a house.

Use a ruler to measure out the lengths of walls. Refer to the two key figures on your floor plan: length and scale. Multiply the length of of the walls by the scale of the floor plan, to get the actual length of the walls in the blueprint. Draw the walls in pencil, in case you need to change them later.

Draw the exterior walls. Because blueprints are relatively high resolution, one wall will likely take up several 36-inch by 51-inch pieces of paper. For a 1:8 blueprint, an 8-foot section of wall will take up 1 foot of paper. Even if the house has a simple layout, draw separate sets of walls for each floor, since you will soon draw interior walls inside these walls. When drawing walls, use a ruler to make sure that the lengths are exactly to scale.

Draw the interior walls. Use the same method you used to draw the exterior walls. Get the scaled-down lengths by multiplying the real lengths against the scale.

Show your wall blueprint to your electrical contractor. Ask them where on the blueprint they will be installing the main indoor and outdoor electrical boxes for the house. Also ask them which walls they will be running the electrical wires through. Make a note of these on a piece of paper, and label the box areas and wired walls accordingly.

Draw the electrical features into the blueprint. Indicate the walls with electrical wires by drawing another line beside them in a different color. Draw small square boxes near the external and internal parts of the house where the electrical boxes will be installed.