How To Read Construction Drawings: A Complete Step-By-Step Guide [& Why They're Called Blueprints]

Summary

This friendly, step-by-step video demystifies construction drawings—what they are, why they matter, and how to read them. Patrick explains common drawing types (architectural, civil, structural, MEP, finishing) and project phases (design, surveys, shop/fabrication, as-builts), then breaks down four key views: plan, elevation, axonometric, and section. Using a sample foundation plan (A101), he highlights scale, legends, grid lines, revision logs, and section callouts, and explains the old ‘‘blueprint’’ process. He finishes with practical rules: think big-to-small, use the latest stamped drawings, coordinate trades, and always rely on structural drawings for load-bearing work—practical advice for newcomers and pros alike.

Takeaways

• 😀 Construction drawings must be printed to scale, as printing on the wrong paper size can distort the dimensions and make the drawing inaccurate.
• 😀 It’s essential to review the general construction notes first, as they contain important information, such as verification of dimensions in the field and references to other related drawings.
• 😀 Symbols and icons used in construction drawings should be understood by referring to the drawing’s legend, which clarifies what each symbol represents.
• 😀 A compass in the drawing indicates the orientation of the house relative to true north, helping to understand the layout in real-world terms.
• 😀 Grid lines are crucial for locating different components of the house. They work like a map, guiding builders to the general location of walls or other features.
• 😀 Revision logs are important for keeping track of changes made to the drawings, ensuring you’re working with the latest version of the plan.
• 😀 Section cuts (marked with symbols like AA and BB) provide close-up views of specific parts of the structure, helping to understand the details of foundations, walls, and other components.
• 😀 The scale of details like foundation sections helps to understand their size and dimensions more precisely, such as the height and thickness of foundation walls or slabs.
• 😀 Always use the latest version of construction drawings and check the revision logs to ensure the plans you’re working from are up to date.
• 😀 Drawings should be stamped by a licensed professional, ensuring that the construction plans are legitimate and have been officially approved for use on-site.
• 😀 When reading construction drawings, it's critical to start with broad, general details before zooming in on specific sections or components to get the full context.

Q & A

What are construction drawings and why are they important?

Construction drawings, also known as blueprints or plans, are detailed visual representations that show exactly how a building should be constructed. They convey design intent, materials, dimensions, and construction methods, serving as the main reference for architects, engineers, and builders.

What are the main types of construction drawings mentioned in the video?

The main types discussed are architectural, civil, structural, mechanical, electrical, plumbing (collectively MEP), and finishing drawings. Each serves a unique purpose, from overall design intent to technical details and aesthetic finishes.

What are the key differences between design drawings, shop drawings, and as-built drawings?

Design drawings show the conceptual intent before construction begins. Shop drawings are created by contractors to show how elements will be fabricated and installed with precise dimensions. As-built drawings are created after construction to record what was actually built, including any deviations from the design or shop drawings.

Why were construction drawings historically called 'blueprints'?

In the 1800s, a chemical process called blueprinting was used to reproduce drawings. It involved exposing chemically coated paper to light, turning blank areas blue while leaving drawn lines white. Although modern prints are no longer blue, the term 'blueprint' remains as a common slang for construction plans.

What are the four common viewpoints used in construction drawings?

The four viewpoints are: (1) Plan view – a bird’s-eye view from above; (2) Elevation view – a perpendicular side view; (3) Axonometric (3/4) view – a 3D depiction on a 2D surface; and (4) Section view – a cutaway that reveals interior construction details.

What does the revisions and changes section of a drawing indicate?

It records updates made to the drawing after its original release. Each revision entry includes a number, date, and description of changes, ensuring everyone works with the latest approved version of the plan.

What is the purpose of grid lines in a construction drawing?

Grid lines act as reference markers to locate components on a site, similar to coordinates on a map. They help construction teams align and position structural elements accurately according to the survey layout.

What are general notes and legends used for in drawings?

General notes provide assumptions, qualifications, and clarifications important for interpreting the drawing. The legend explains symbols, textures, and abbreviations used, helping viewers understand non-labeled graphical elements.

Why is it important to ensure that drawings are stamped?

Stamped drawings are those reviewed and approved by licensed architects or engineers, confirming they meet code and permit requirements. Unstamped drawings, except for minor finish details, are not legitimate for actual construction.

What practical tips does Patrick provide for reading construction drawings effectively?

Patrick advises readers to start by understanding big-picture details before focusing on smaller ones, always check for the latest revision, refer to structural drawings for load-bearing components, ensure coordination among different trade drawings, and verify that drawings are stamped before starting any work.

What is the main message or goal of the video?

The video aims to teach viewers, especially beginners in construction and project management, how to read and understand construction drawings step by step. It breaks down key concepts, terminology, and practical advice to make the process approachable and clear.