Chapter 5 - Undrstanding Construction Plans

A set of construction plans will consist of several sets of drawings.

Architectural Drawings


Structural Drawings

Mechanical Drawings

Electrical Drawings

Civil Drawings



The core set of drawings you produce will be the architectural drawings. These are typically designated with an A prefix and numbered sequentially. They start in sequence with the basement or ground floor plans, upper floor plans, exterior elevations, details and finally schedules of windows, doors and finishes.

The plan view is the most common of the architectural drawings and the most common plan view is the floor plan. The floor plan communicated the use of space, location of rooms, access, window and door locations, and built-ins such as cabinets. Architectural plans should include dimensions to show actual length and width, which will allow the reader to calculate the area of any given portion of the plan. The dimensions should be clear and accurate, showing both exterior and interior dimensions. Your architectural plans will also include notes that will provide information about segments of the work or reference other drawings.

The plan view will also be utilized for roof plans, or suspended ceiling plans, and any other time a top down view is the best way to convey the most information.

Exterior elevations are used to provide a pictorial view of the exterior walls of a structure somewhat like a photograph. Because it is exactly perpendicular to the vertical and horizontal plane, an elevation view will show very little depth. The exterior elevations for the working plans can be titled North, South, East and West, or Front, Rear, Left side and Right side. The elevation views bring a clear vision of exterior doors and windows, as well as facades and surface materials to the plan set. Use numbers and letters in circles to reference window and door types to their respective schedules.

Elevations also provide measurements in a vertical plane with respect to a horizontal plane. These dimensions will provide a vertical location of floor-to-floor heights, window sill or head heights, floor-to-plate heights, and roof heights. These measurements will also help in the calculation of materials quantities.

Building Sections are slices through a structure at a particular place in the structure. It is intended to offer a view through a part of the structure not shown in another drawing. Several different sections can be included in the drawings in both a cross section view of a plan view or as a wall section of an elevation view.  Wall sections serve to communicate an exposed view of the components and arrangements inside the wall itself. By viewing the sections together with the floor plans and elevations the plan reader should start to get a sense of how the whole structure goes together.

Detail drawings offer clarification by enlarging the view of particular areas of the drawings. The detail enlargements are drawn to a larger scale and can be found on the sheet where they are referenced or grouped together on a separate Details sheet.


Are used to keep drawing from getting too cluttered with notes and printed information. Schedules are arranged as a series of tables that pertain to a given group of items. For example doors, windows, trusses, lighting or plumbing fixtures should all have a schedule in the plans.

A typical schedule will consist of in formation such as size, type, material, hardware, source, and any pertinent remarks.   


Provide a view of the structural members of the building, explaining how loads will be supported and transmitted to the ground. Like the Architectural drawings, “structural’s” are sequentially numbered but prefixed with an “S” rather than an “A”. Locate them after the Architectural drawings in the set.

Your structural drawings will start with you foundation plan, a first floor plan that clearly shows the engineered elements (ISBUs) and then a roof plan. Show only the structural elements; leave out partition walls, doors, etc. The structural drawings will also consist of plan views, sections and details in the same format as the architectural drawings.


Follow the structural drawings. As you would suspect the mechanical drawings explain the mechanical systems such as plumbing, HVAC, and fire protection, each designated respectively with a letter, “P”, “H”, or “FP”.

Mechanicals are usually drawn in plan view allowing a diagram that illustrates the locations and configuration of the work. The large number of connectors, valves, various pipes and other items needs for the mechanical systems requires that symbols be used to convey the scope of the work. These symbols will be incorporated into a “Legend” which explains the symbols and abbreviations on the plans. In addition the schedule format is incorporated to list the items required.

ELECTRICAL DRAWINGS make up the last set in the plans. Again, number sequentially and prefixed with an “E”. Included will be plans for electrical power, lighting plans, telecommunications, and security wiring. With a simpler design you may be able to place power, lighting and telecommunications all on one plan. Typically the electrical plans will include panel schedules that list circuits as well as the individual power for each panel and total power needs. These schedules will help the electrician select the appropriate panel.


Generally consist of site plans, and any other work that doesn’t involve the structure itself, including drainage, utilities and landscaping. The site plan is many time omitted from residential plans simply because the site hasn’t been determined yet.

Note that civil drawings make use of engineer’s scale, which allows scales as small as 60 feet to the inch, to allow for the larger dimension involved when measuring land. 

The advantage of designing a structure for a specific site is the opportunity to study and resolve some of the bigger design issues effectively at the very onset of planning.  Designing a home without a specific site in mind leaves a strong possibility that not all sites will prove suitable for your design or that your design will need some modifications to be accommodated on a specific site.

In many cases this first stage will include adapting the home design to the characteristics of a chosen site, but just as often the site characteristics are unknown. In either case thought and consideration should be given to your local climate conditions.

At the least the climate will influence how you will want to orient your home in relation to the sun, the prevailing winds, and the seasons. If you live in a warm arid climate you may want to capture and direct cool air to the inside of your home. If excess heat is a major problem in your region, passive-cooling techniques should be among your primary design considerations. Think about how and when the breeze blows and how to capture it. If you live in a colder region you may want to plan for extra insulation and a solar sink to collect heat for dispersal during the cooler periods.



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