Home The Basics of Reading Blueprints
Glossary of Building Terms
The most important aspect of a new home is the purchase of or the drawing of construction plans. Using the least expensive designer or purchasing stock plans that are not adequately drawn could cost thousands of dollars during construction.
The plans list the services and materials needed to build a home. Contracts and agreements are based on your plans and it is of utmost importance they be complete, clear, and comprehensive, to insure that the home is properly constructed, in an honest, orderly and timely manner.
The plans must comply with national and local building codes, and include all drawings, schedules, and specifications necessary for take-offs, bids, permits, and construction.
Plot Plans are drawn to determine the placement of the home on the building lot. A plot plan again is an overhead view of the construction site and the home as it sits in reference to the boundaries of the lot. Stock house plans usually do not include plot plans since they are drawn specific to the site where it will be built. Plot plans can be drawn by a local professional draftsman, architect or engineer. Plot plans should outline location of utility services, setback requirements, easements, location of drives and walks, and sometimes even topographical data that specifies the slope of the terrain.
Home plans are drawn to scale so that if a specific dimension needed is missing, the contractor can scale the drawing to determine the right measurement.
Typical scales used in the United States are:
The following scales are generally grouped in pairs using the same dual-numbered index line:
The main floor plans are generally drawn to Ό" scale which means that every Ό" on the plan equals 1' in actual length. Other details like framing layouts or built-in details may be drawn at another scale like 1/8" or even Ύ". The scale of each drawing is usually called out beneath the drawing or somewhere on the page, usually next to the title.
Elevations are a non-perspective
view of the home, straight on. These are drawn to scale so that measurements can be
taken for any aspect necessary. Plans include front, rear and both side
elevations. The elevations specify ridge heights, the positioning of the
final grade of the lot, exterior finishes, roof pitches and other details
like windows, doors, gables, hips, that are necessary to give the home its exterior architectural styling.
Floor plans are actually quite easy to understand. A floor plan layout on blueprints is basically an overhead view of the completed house. You'll see parallel lines that scale at whatever width the walls are required to be. Dimensions are usually drawn between the walls to specify room sizes and wall lengths. You'll also see on the floor plan locations of fixtures like sinks, water heaters, furnaces, etc. Among the walls and dimensions you will often find notes to specify finishes, construction methods, or even symbols for electrical or to reference cross sections.
Electrical Layout: Electrical layouts are
sometimes on a separate page to make reading them a little easier. The
layout will show locations of light fixtures, fans, outlets, light
switches etc. There is usually a legend on the page which explains what
each symbols represents. For illustration purposes we have included such a
legend below. There may be such legends for heating systems, door swings
and sizes, or even to specify certain finishes.
Details: Overhead views or floor plan views of the structure don't
always provide enough information on how the home is to be built. Often
times cross section or details will explain certain special conditions
more appropriately. A cross section is basically a view of the home if it
were sliced down the center. This allows you to view the home from the
side and understand a little better the relativity of varying floor
heights, rafter lengths, and other structural elements.
For a large blown up view of Details Click here
Construction plan specifications in North America:
Specifications form a part of the contract that documents and govern the construction of a building. While there is a tendency to believe that "Specs overrule Drawings" in the event of discrepancies between the text document and the drawings. The actual intent is for drawings and specifications to be complimentary with neither taking precedence over the other.
Specifications can be "performance-based", whereby the specifier restricts the text to stating the performance that must be achieved in each Section of work, or "prescriptive", whereby the specifier indicates specific products, vendors and even contractors that are acceptable for each workscope. Specifications of some sort are a must for a contractor to properly bid the cost of a job. All building material must be identified as to grade and placement, such as steel in concrete, concrete PSI slab, grade of lumber, plywood, plumbing, shingles, sheetrock, paint, floors, and especially wall and ceiling insulation, or entire envelope insulation.
These are the basics of reading a house plan; keep in mind however that what is included in plans will vary according to the designer who drew them. House plans are a very important part of the homebuilding process. It is crucial to purchase a plan drawn by a home design professional since they have a thorough understanding of how homes are built. If there were any terms on this page that you did not understand or would like a more thorough description of their meaning, please visit our construction terms glossary.
|Home Link to Glossary of Building Terms|