Construction blueprints are sets of two-dimensional drawings or plans. They comprise all the details and specifications of a project – including the name of its architect, visual representation of the building, dimensions of the structure, construction materials to be used, the layout of electrical wiring, and more. Typically, the size of these plans varies between 18×24 inches and 24×36 inches, depending on the scope of the project.
These engineering drawings are typically printed on white or blue papers and homeowners require these to obtain construction permits from concerned development authorities.
Moreover, each set of blueprints contains multiple sheets. Construction plans, construction drawings, building plans, and floor plans are all types of blueprints.
WHY ARE BLUEPRINTS IMPORTANT IN CONSTRUCTION?
Blueprints are the core of any construction project.
These drawings put the engineers, architects, contractors, labourers, homeowners and officials from concerned development authorities all on the same page. They also feature all of the technical and physical specifications of the project in one place, enabling contractors to determine how much time it would take for the time and cost required for the completion of the project.
In addition to that, development authorities only approve building permits after evaluating these blueprints. You can only begin constructing your house if these construction drawings are in perfect compliance with the local building codes.
They also serve as great resources for modifications, maintenance and future renovations.
TYPES OF VIEWS IN CONSTRUCTION BLUEPRINTS
The first step in how to read structural drawings is understanding the different perspectives or angles used by architects and engineers while developing blueprints.
There are three types of views used in construction drawings:
Plan View: This type of construction blueprint is on a horizontal plane and depicts a bird’s eye view of the structure from above. Each floor in the building also has a separate plan view drawing.
Elevation View: This drawing is on a vertical plane and depicts how the structure would look from the front, back, right, or left side. These include both interior and exterior elevation view drawings.
Cross-Section View: This construction plan is also on a vertical plane, though it slices through the structure to show its interior. The cross-section view depicts the placement of wall studs, insulation material and sheathing etc.
ANATOMY OF CONSTRUCTION BLUEPRINTS
To decode a blueprint, you must learn about its anatomy and become familiar.
Here are the main features of construction blueprints that all homeowners must know about.
While reading construction blueprints, you will notice a small rectangle at the bottom right corner or a narrow band expanding across the length or the width of the drawing sheet with basic project information. This is called the title block and it often includes the drawing or print number of the sheet as well.
This block usually contains important information related to the project, such as:
- Logo, name and contact information of the construction company
- Name of the architect
- Name of the client
- Project title
- Site address and location
- Title of the drawing
- Date it was drawn
- Total number of sheets
As the name suggests, the revision block comprises the dates and descriptions of all of the changes that have been made to the blueprints over a period of time. This block also features the signature or initials of the person(s) who authorized those revisions.
All blueprints include a grid system along the vertical and horizontal axes with numerical digitals present on one axis and alphabets on the other.
KEY NOTES AND LEGEND
Architects include general notes about the project along with a legend comprising keys to each of the construction blueprint symbols at the very bottom of the sheet.
The information mentioned in this section can be relevant to the entire project or specific to a particular drawing. The legend also makes it easy for homeowners to read and understand the blueprint without much hassle.
DRAWING OR PLAN
The space at the centre of a blueprint is dedicated to the layout or drawing, which illustrates the view, floor plan and main features of the project.
TYPES OF SHEETS IN A CONSTRUCTION BLUEPRINT
Construction blueprints comprise multiple sheets. So, to ensure that they don’t get mixed up, architects label these drawings with a letter code and sheet number.
Here is a breakdown explaining what each code in construction blueprints stands for.
G SHEETS: GENERAL SHEETS
General sheets begin with a cover sheet followed by a comprehensive index that lists each of the sheets included in the set of blueprints. They typically include the site plan, placement of the building, project boundary, landscaping, setbacks, driveway, power lines, and sewer pipes, to name a few.
A SHEETS: ARCHITECTURAL PLANS
Architectural drawings or plans include roof and floor plans of a building. It also includes the visual representation of the elevation of the structure, illustrating how it will look from each side once completed. A-Sheets may also include close-up drawings of various elements such as the location of windows and doors, layout of walls, and the dimensions of each room etc.
If you are unable to read architectural drawings by yourself, please make sure to ask an expert for help to avoid any confusion or miscommunication.
S SHEETS: STRUCTURAL ENGINEERING PLANS
While architectural drawings give you a clear picture of how the building will look once completed, the structural drawings or S-Sheets show you how to actually construct it.
A structural engineer creates these drawings after studying the ones made by the architects. These sheets comprise information about the foundation, frame, concrete reinforcements, rebar, roof structure, and other elements that ensure the structural integrity of a building.
M SHEETS: MECHANICAL PLANS
These sheets include the layout of heating, ventilation, air conditioning and fire protection systems, along with other mechanical equipment utilized in a building.
E SHEETS: ELECTRICAL PLANS
The details about the electrical wiring along with the location of circuits, breakers, panel boxes, switches, smoke alarms, light fixtures and other built-in appliances are illustrated in E-Sheets.
P SHEETS: PLUMBING PLANS
The P-sheets feature plans for hot and cold water pipelines in a building along with a sewage system and storm drainage. Gas pipelines are also illustrated in these sheets.
L SHEETS: LANDSCAPE PLANS
The details of the area around the building that will be used to plant trees, flowerbeds and shrubbery are depicted in L-Sheets.
These sheets feature a table or a matrix comprising information about the construction and finishing schedules of different portions of the project.
Specification sheets feature comprehensive descriptions of all the materials that are to be used in the project.
HOW TO READ THE BLUEPRINT SHEET CODES?
Each sheet in the set has its own code containing one or two alphabetical letters followed by a numerical sequence. The first letters denote the type of sheet, i.e. A for architectural, S for structural, E for electrical and so on. Meanwhile, the middle numerical represents the sheet type. For instance, 0 is used for general information, 1 is used for plans, and 2 for elevations. The digits at the end of the sequence signify the number of the sheet.
For example, a sheet numbered M103 will contain the third sheet of mechanical plans.
On a side note, if you are planning to construct your house.