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How to Read House Plans


Interpreting House Plans

Other than the artist's rendering of the exterior of the house, most of a house plan won't look much like a house. Instead, it's filled with standardized symbols that represent parts of your house. When a builder looks at house plans, he sees doors, windows, walls and electrical outlets, represented by symbols. Once you understand the symbols on a house plan, you'll see the house the way he does. Here are some basics on reading plans:

  • House plans are drawn to scale, meaning that when you multiply the lengths of the lines in your plans by a previously determined number, you wind up with their length in real life. There are no absolute scales used for all house plans, but commonly the minimum scale for a site plan is 1 inch equals 20 feet. For foundation, floor plans and elevations it's 1/4 of an inch equals 1 foot, and for sections and details 3/8 of an inch equals 1 foot [source: National Council of Building Designer Certification]. Because a plan is drawn to scale, it shows everything exactly as it will be built relative to everything else around it -- even though it's obviously much smaller than your house will be. For example, this means that an exterior wall that looks thicker than an interior wall on your plans will, in fact, be thicker in real life. To get a feel for scale, look at one of the floor plans and calculate the real-life measurements of a major room. Then compare those measurements to rooms in the house where you live now. Imagine the remaining rooms, hallways and traffic flow in your plan relative to this room you've measured out, as well, to help you get a feel for your future home.
  • Nearly every feature commonly seen in houses is represented by a standardized symbol on a plan. For example, there are nine common symbols to represent various types of doors, ranging from French, to swinging, to bi-fold, to accordion [source: eHousePlans.com]. Search online or work with your architect or builder to understand these many symbols (and see our handy guide above). It's worth working to understand at least the symbols for doors, windows and electrical outlets.
  • Specifications: In addition to showing what your house will look like and how big each room will be, it also will describe how these parts will be made and what they should be made of. Your specifications sheet describes fixtures, appliances, materials and other homeowner preferences. Even if you buy premade house plans, you may still have significant wiggle room to change its specs. Consider picking wallpaper, stains, paints, fixtures, hardware and other materials [source: Byoh.com].

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