Blueprints: How to Read the Construction Designer’s Handwriting

Blueprints are the universal language of builders and contractors. They are the way that everyone on a particular project works together to achieve the same final product. From building plans to electrical layouts, blueprints show every detail of the project.

To the common eye, blueprints can be intimidating and difficult to interpret. However, building plans can easily be interpreted by understanding how to read them.

First and foremost, the title page of the blueprint gives vital information. The title page will include a list of all drawings to show what is included in the entire project. This shows an overview of the project. The title page also contains a list of symbols and abbreviations that are used in the blueprints.

Scale is involved with every blueprint. A scale is a proportional representation of the larger project. Most commonly, blueprints are drawn on a one-eighth of an inch scale. For every one-eighth of an inch on the blue print, it represents one foot of construction material. Other common scales include one-sixteenth of an inch for one foot of construction or one-fourth of an inch for one foot of construction.

Everything should be properly labeled on a blueprint. Rooms are usually presented in a logical fashion. In order to see where the walls are placed, look for lines. Exterior walls are drawn with thicker parallel lines and interior walls are represented with thin lines.

Architectural drawings, marked with a capital A after the number, give an overview of the entire project. On the blueprints, the architectural drawings show floor plans, exterior elevations, and finished selections. Mechanical drawings, marked with a capital M after the number, determine where different utilities and pipes go. This includes heating systems, air conditioning systems, and plumbing information. Electrical plans are marked with a capital E after the number. They show the locations of light fixtures, receptacles, switches, and wiring.

Along with every blueprint comes a spec book. A spec book is the specifications manual, which provides information about the materials being used on the project. The spec book also shows the method and how the builders are planning to achieve certain goals of the project.

Blueprints are not the easiest puzzle to solve. Continue to look at the blueprints until they make sense to you. Use the title page and spec book to help gain a greater understanding of the project.

While blueprints are set with a clear plan, most construction projects are adapted or changed as they progress. Amendments are often added to the blueprints as a project continues. Always make sure the blueprints you are looking at are the most updated.

As a valuable resource, D. R. Hartman Construction Inc. is ready to assist any customers in the Bethesda, Gaithersburg and Silver Spring, Maryland regions as they read blueprints. D. R. Hartman Construction Inc. offers valuable builders and superior customer service to work with the customer from the initial blueprint to the finishing touches on any construction project. For more information on how D. R. Hartman Construction Inc. can assist new home owners or those looking to improve their home, call us today at 301-926-9000 or visit

Photo credits: Top © Dana S. Rothstein / Fotolia. Middle © Marcus Lorenz / Fotolia. Bottom © Viktors Neimanis / Fotolia.

D.R. Hartman Construction Inc

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