Understanding Architectural Blueprints

Most people who have experienced building construction are likely to know what a blueprint is. It is a standard method of communication for workers, used to copy large architectural and construction drawings.

In the past, architectural blueprints used to have white lines on blue backgrounds but in recent times, white backgrounds are used with blue lines. We will be taking a deep dive into architectural blueprints and all you need to know about them.

What is a blueprint?

Blueprints are used for the reproduction of architectural or engineering drawings by a contact print process on sheets that are light-sensitive. Blueprints were introduced by Sir John Herschel in 1842 and were a means of quickly and accurately producing unlimited copies of drawings.

This process was widely used for over a century, and though not as common anymore, the word ‘blueprint’ is still popular among architects, engineers, drafters and construction workers to refer to floor plans.

Why is a blueprint blue?

The process of making blueprints is what gives it the distinct color.  It starts out with creating a drawing on translucent tracing paper. This is then placed on paper that has been coated with ammonium iron citrate and potassium ferrocyanide: the blueprinting paper. The mix is derived from an aqueous solution and is left out to dry.

The two papers, when placed together and exposed to bright light, causes the chemicals to react and form a blue compound called blue ferric ferrocyanide. It is also referred to as Prussian blue. The parts that end up not being blue are those covered, where light is blocked by the lines of the original drawing. This leaves a negative white image against a dark blue background.

The process was considered to be quicker and less expensive than hand-tracing. Even after the introduction of carbon copying and the use of copier machines, professionals in the built environment continued to use this method for large scale drawings.

What is blueprint paper?

Blueprint paper is paper that is specially coated and turns blue when certain areas are exposed to light. These are the materials required for making blueprint paper:

Petri dish, tongs, white paper, a small opaque object such as a coin, leaf or key, 15 ml of 10% potassium hexacyanoferrate (III) (potassium ferricyanide), 15 ml of 10% iron (III) ammonium citrate solution.

What is the purpose of an architectural blueprint?

The major purpose of an architectural blueprint is to reproduce large drawings, and a reason why it is still being used is its inexpensiveness. When compared to the cost of large-format copying machines, it is considered a great bargain.

Blueprints are also preferred as they are less time consuming and easily recognizable as a result of the blue background colors and white lines. They create accurate negative reproductions of original drawings.

Do architects still use blueprints?

There have been a lot of modern day processes and technologies used to replace blueprinting. It started out in the 1940s when the original blueprint being replaced by blue lines on white paper. This process is what is now replicated in modern times by computer aided printing technologies.

In present times, it is no longer a necessity that architects or engineers print their drawings onto paper as they can easily be displayed digitally. The digital images can then be transferred to builders and other professionals in the construction environment.

The blueprinting process can be termed as obsolete as it has been replaced by large-format xerographic photocopiers.

What is the difference between a blueprint and a plan?

A plan is a scaled drawing of a building or a part of it. It shows the placement of fixtures, appliances and openings such as doors and windows. A plan can be used as a guide for planning, construction cost estimation, material selection and calculating square footage. The ‘plan view’ shows rooms from the top view with the roof removed.

Blueprints are more detailed and technical than regular floor plans. A complete set of blueprints includes floor plans, elevations of all sides of the building, basement and foundation drawings, electrical drawings, framing plan, plumbing and mechanical systems, cross sections , roof plans, plot plans and many more. They are usually drawn on 18 x 24” or 24 x 36” sheets.

How to make your own blueprint

Some of the tools required to make your own blueprint are; architect’s scale, pencils/pens, T-square, tracing paper, masking tape, flat working surface, compass, ruler and eraser.

The right side corner of the sheet houses the title block i.e. the name of the view, scale of the drawing, name of designer and the date.

Begin with drawing the exterior walls of the building then slowly move on to the interior walls and then the doors and windows.

Proceed to labelling rooms then locating fixtures and appliances. Next step is to draw electrical symbols and label floor surfaces.

Dimension your drawings accurately and remember to dimension each room, the cabinet depths, closets, and distances from walls to edges of appliances.

Lastly, create a window and door schedule.

How to read a blueprint

Learning to read blueprints is a necessity for those in the construction and architectural field. They are 2-dimensional design drawings that indicate building features. Here are a list of things to look out for when reading a blueprint:

Step 1: Title Block

They are usually at the start of the blueprints. You would want to make sure you take a thorough look at it especially when involved in major construction work.

The title block consists of the blueprint name, names, location, site and vendor. This part of the blueprint helps with proper filing and documentation.

The second section of the title block houses approval dates and signatures, while the third comprises of a list of references and related drawings.

Step 2: Revision Block

Whenever changes are made to the building, the drawing has to be redrafted. The list of changes can be found in the revision block.

Step 3: Notes and Legends

Blueprints often consist of symbols and numbers different from the standard grids and lines. Legends are essential to fully understand what the symbols mean. Be sure to learn the symbols in order to comprehend the drawings.

The notes showcase the drawing specifications and other information the designer believes will aid the understanding of the plans. Reading notes is important, especially in construction, as details as minute as what time construction should commence can be located in there.

Step 4: View determination

There are three common perspectives with 2D blueprints which are: plans, elevations and sections. It is important to know which one is being employed when reading drawings.

A plan is a bird’s eye view of a drawing. It precisely showcases the width and length of spaces. Plan views are done on a horizontal plane at 30 inches above the floor.

An elevation is the view of a drawing from any one of the sides. The North, West, East or South orientations are typically employed in determining an elevation. Elevations allow for calculation of height dimensions.

A section is the view of a space as if it were cut through. It is generally imaginary and is used to show the inner working of building construction and material setup.

Step 5: Scaling

Blueprints do not represent the actual measurement of buildings but a scaled down version. In order to ensure construction is done properly, it is important to use accurate measurements. The scale shows what the measurements on the drawing are equal to in real life.

The scales are used for both interior and exterior architectural drawings and for establishing building components such as doors, windows and walls.

There are engineering scales and civil scales as well, which are used for public water systems, highways, roads and topographical elements. Common scales include 1/4″=1′ and 3/32″=1′.

Step 6: Grid System

Locate grid systems that go along the vertical and horizontal axis of the blueprint. They typically contain numbers on one end and letters on the other. They allow for easy referencing of locations of objects and points within the drawing. E.g. referencing a door centred at point B9.

This especially comes in handy when discussing points on a drawing with someone who is not physically present. It is more likely that they are able to identify the same thing from miles away.

Step 7: Find the doors and windows

Doors are typically represented with large gaps between walls that have a curved lines extended in or out of the door frame. This shows in what way the door will swing when opened. Windows are similarly shown and are drawn to scale depending on their size.

Blueprints should include door and window schedules. They contain information on the size, material style and shape of each door and window. Door and window schedules can be as detailed as required for the project, and some go as far as indicating the type of locks and handles of doors.

Step 8: Identifying appliances

Appliances are usually represented by simplistic but recognizable materials on blueprints. Take your time to make sure that toilets, sinks, fridges, stoves and so on are placed in areas where they should be. These items and their placement can play a major role in design specification and space utilization.

Blueprints typically include finish schedules as they highlight the style and model of the various appliances in the building.

What font is used for blueprints?

Fonts are a necessity for expression in architectural and construction drawings as they make up the boards and panels, and give the drawings an identity. Fonts are the pillar of graphic design and they can assume various shapes and sizes, ranging from light to bold and italic. They can be in upper or lower case, cursive, ornamental, with or without serif and many more possible features.

It is advised that the right font is used in architectural drawings and blueprints in order to be able to convey the message properly. Here is a selection of some appropriate fonts for architectural blueprints:

Gotham: This font style is used mostly for publicity, in signage and architectural visual identity. Gotham was created by Tobias Frere-Jones in the 2000s and is believed to possess credibility in its lines. Hence its usage for logos and even business cards.

Futura: This font style was inspired by Bauhaus techniques and combines both straight lines and curves. Futura was created by Paul Renner in the 1920s and is highly used in corporate buildings for visual identity. It is however important to note that the font style should not be used in long texts as it can be visually exhausting to read and understand. This font style is popularly used for titles and subtitles in blueprints and architectural boards.

Neutra: This font was designed by Christian Schwartz, Julius Schulman and Dion Neutra. It was done in honour of the modernist architect, Richard Neutra. It is regarded in the drafting world as a competitor for the Futura font style.

Bauhaus: Mostly used in titles and subtitles of composition boards, this style was created by a graphic designer in 1925. Herbert Bayer, the creator, thought of it as timeless and transcending time. Herbert studied in Bauhaus in the 1920 under Kandinsky and Moholy-Nagy. Bauhaus font is usually installed with the Windows application.

Bodoni: This font style is known for its high aesthetic strength and should be used with caution. The letters are striking and not suitable for long texts but for highlights, titles and details. It was created by Giambattista Bodoni in 1767.

Summary

In construction today, ‘blueprints’ are viewed directly on displays rather than printed paper sheets. Such displays include mobile phones, tablets and computers. There are various software in place to enable users view and annotate electronic files and render architectural drawings.

A lot of the original paper blueprints are now archived or no longer in use. Some professionals have gone as far as digitizing old blueprints rather than storing paper. Most construction work done before c. 1990 will be in original blueprint form though.

The original drawings are still significant in modern times because they are required for repair and alteration work carried out on structures such as bridges, sewers, roads, railroads and much more. The original blueprints also come in handy for legal reasons such as boundary determination and responsibility for boundary walls.

Whatever your construction needs might be, blueprints could definitely be of some use.