House Plans 101
Expert tips for reading blueprints like a pro
Expert tips for reading blueprints like a pro
These days, you’re able to review more than just the blueprints before construction begins. You’ll likely get a complete package of construction documents showing your future home from almost every angle imaginable. To the layperson with no training in architecture or engineering, all the information can be overwhelming.
WHAT ARE BLUEPRINTS?
The term “blueprints” is a little out of date: Pre-computers, architects created hand drawings on vellum paper, then laid vellum over blueprint
paper, which had a blue tint to it, and processed the documents in ammonia through a blueprint machine in a manner similar to film developing. Now, they’re mostly digital versions or photocopies of computer-aided design (CAD) drawings, which instead feature black and white lines that are much easier to read.
The results are usually printed on 18-by-24-inch or 24-by-36-inch paper, also aiding in readability. Another bonus to this new method: Homeowners can have their complete house plans stored online to be downloaded or on a zip drive to be saved to their computer’s desktop.
GET TO KNOW YOUR DOCUMENTS
When you receive your construction documents, your architect or builder will probably review them with you. Still, it can be difficult to visualize your finished project from blueprints. To get a better understanding of what you see on paper, ask your architect or designer any questions that come to mind. And be sure to spend a good deal of time looking through the plans. To navigate your way through them, refer often to the legends page shown on page 22.
Your next step is to familiarize yourself with basic construction document elements. You will need to understand or recognize the following:
The main floor plans are usually drawn to ¼ scale. In practical terms, this means that every ¼ inch on the plan equals 1 foot in actual length. Different parts of the plan, such as framing layouts or built-in details, may be drawn to 1/8 or 3/4 scale. From this, the builder scales the home to calculate the correct measurements for walls, openings, etc.
Basement or foundation floor plan:
Showing the location of the loadbearing walls, footings, rebar concrete reinforcements and other structural components, these plans outline the structural integrity of the home and what supports its roof and walls.
These drawings show the home from the front, rear and side perspectives. Elevations are designed to give you an idea of what the finished home will look like, as well as its mass, height and width. You’ll see the location of the window openings,
exterior finish treatments, roof pitches, ridge heights and other architectural details.
The easiest to understand of all the construction documents, floor plans provide a bird’s-eye view of the completed house. They show the home’s layout and include room dimensions as well as the location of bathroom and kitchen fixtures, stairs and water heaters, among other things. Denotation of interior finishes, construction methods and symbols for electrical and plumbing designations are often included.
Electrical layouts show the location of light fixtures, fans, outlets, light switches and more, and they come with a legend that explains each symbol. These documents are usually separate drawings electricians use to wire the home.
Drawn to scale, framing plans show the basic skeleton of a house from the floor joists to trusses to beam locations to the walls. Often, they include instructions for wall construction.
Cross sections and details:
Cross sections — drawings of the completed home cut in half — are included in the construction documents because floor plans don’t always provide enough information on how the home will be built. These plans are generally more helpful to homeowners to relate to the size of their spaces than in the actual construction of the project. For instance, a great room might have 20-foot vaulted ceilings. An architect or designer might insert a graphic representation of a 6-foot human to show how a person of that height would relate to the height of the ceiling.
Plumbing and mechanical system layouts:
Plumbing and mechanical system layouts show the location of fixtures and main water lines. More detailed plans are drawn up by heating or plumbing specialists for complex heating systems such as radiant heat or engineered forced-air systems.
Plot (or site) plan:
A plot (or site) plan is a drawing of the site where the home is going to be built. In addition to the placement of the home on the parcel, it shows the location of utility services, setback requirements, easements, driveways and walkways.
You don’t need a degree in architecture to read and understand construction documents. We’ll show you what to look for so your project turns out just the way you planned.