This section will provide you with a general understanding of blueprints and how to read them.

Contents:

• How do I read a blueprint?
• What are some of the symbols?
• What are the various drawings and their functions?
• What are some of the abbreviations?

What is a 'blueprint'?

Originally, 'blueprint' was a term that referred to a method of reproducing a drawing. This process created an exact duplicate with all lines being blue. Although blueprints are still used, the technology of computers and printers make it uncommon. Sets of drawings are often reproduced on a 'bond' paper which is black on white. Generally, the word 'blueprint' is now used to refer to these copies of drawings, rather than the actual blue line prints.

How do I read a blueprint?

The first thing to consider when reading a technical drawing of any kind, is scale. Every drawing in your set of house plans should have a scale, which can be defined as a ratio of distance. For example, a plan can be reduced to 1/4"=1'0" which means that for every 1/4" measured (on the drawing) it represents 1'0" in reality. The drawing has been scaled down to fit on the paper. As you can see, it would be impossible to draw plans without these ratios.

Continuing with our discussion of scale, we will now introduce you to two types of scales: Architectural and Engineering. Although both serve to assist in measuring distance in a drawing, they have some differences. Here are some examples:

Architectural Scale:

Engineering Scale:

What are some of the symbols?

Within any technical drawing, you will find many different symbols. Although architects, engineers, drafters, and contractors will have their own versions of these symbols, they will still function consistently with the standards listed below:

• Detail Designation

  These are used to indicate the location of an enlarged detail in order to show more information than what appears in the current drawing. They are also used to highlight the area of the house that is being enlarged.

• Section Mark

  These are used to indicate that there is a drawing showing the house cut at that point. This cut is to show the insides of the house, including the structure and all the inside elements.

• Elevation Detail Symbol

  These are used to indicate a drawing of what an area will look like from a straight on view. These drawings are usually meant to show heights, interior and exterior features and design intent.

• Elevation Mark

  These are used to indicate the height of a particular object. An elevation mark is normally found on a Reflected Ceiling Plan (a drawing looking up at the ceiling) or an Elevation Drawing, interior or exterior, and is usually attached to a number.

• Title

  The title mark reveals the detail number, sheet location, and a title. The title will usually be descriptive of the detail.

• Center Line Symbol

  Center line symbols are used to indicate that something is either dimensioned to a center line of a wall or an object.

• North Arrow

  A north arrow does exactly what you'd expect: it indicates which direction is North. This symbol is most commonly found on site and floor plans. Though it can be found in many different styles and versions, below is the most common:

What are the various drawings and their functions?

There are many technical drawings that will accompany a project as complex as building or remodeling a home. Some of these are listed below:

• Site Plan:

A site plan should be drawn first, and should appear first in the final set of drawings. There is a great deal of information on a site plan that is vital to your house project. The site plan will show everything from code issues to landscaping, and most importantly the location of the house on the site. Some specific functions you will find on a site plan are drainage (contours of the site), trees and other landscape elements, setbacks, and property lines.



• Floor Plan:

The floor plan is the drawing that governs the design of the house. Floor plans usually require the most attention by the designer and show the overall layout of entrances, rooms, windows, and any special features within the house.



• Building Sections:

These drawings are cross-sections of the house. They allow the reader to view the house as if it were cut in half. This type of drawing is important for the architect to determine if there will be any design issues or conflicts. For the contractor, this drawing provides visual cues on how to proceed with the construction. Finally, for the owner of the house, this plan will help in visualizing the finished product. Floor plans use section marks to indicate a building section.



• Wall Sections:

Wall sections are similar to building sections except they are only intended to show the construction of one exterior wall. These drawings usually appear at a larger scale so that more detail can be included. As with building sections, a wall section is indicated on the floor plan with a section mark.



• Exterior Elevations:

As with floor plans, the Elevation drawings are vital in modeling the design of the house. Elevation plans will document any exterior features, such as decks and porches. They will also reveal window and door locations, eave heights, and roofing dimensions. The elevation plans should always be included in the set of drawings, and are referred to by the elevation detail symbols on the floor plans.



• Interior Elevations:

These drawings are not always included in a set of house drawings, though they might appear if an arhitecture firm was hired to design the house, or if the house if of sufficient size or complexity to warrant their use. Interior elevations are intended to show the design elements of the interior. They could indicate finishes, trims and colors. An elevation detail symbol is used to reference these drawings.



• Reflected Ceiling Plan:

As with the interior elevations, these drawings are usually found in large scale project plans, or when architecture firms are hired. The purpose of these drawings are to reveal the lighting layout and any ceiling conditions.



• Details:

Within a set of drawings, there will be many areas that need further detail. Using a drawing at a larger scale, this can be accomplished. Though not mandatory for every house, details can be found if the project is of sufficient complexity. The details are indicated with a detail designation symbol.

What are some of the abbreviations?

• MAX - Maximum
• MIN - Minimum
• MTL - Metal
• ELEV - Elevation
• O.C. - On Center
• A.F.F. - Above Finished Floor
• FIN - Finish
• R.O. - Rough Opening (usually for windows)
• DWGS - Drawings
• G..C - General Contractor
• T.M.E. - To Match Existing
• N.I.C. - Not in Contact