UNDERSTANDING ARCHITECTURAL DRAWINGS
Architect's are more valuable to their clients if they are able to convey their design into a format that is suitable for construction. Architects are typically able to visualize concepts in 3 dimensions (3D), often solving many of the design problems prior to putting pencil to paper (or mouse to the mouse pad). 3D drawings are great for presenting the design to the owners and users, but typically terrible for construction activities. Unfortunately, its very difficult to convey the information necessary for the actual construction in a 3D format without hiding important information due to limitations of perspective views. For instance, if you are viewing the front of a building on an angle, how would you show the back of the structure? How can you show the alcove behind a projection? How many 3D drawings would be required to show all the information needed to construct the building?
In this blog article, we will explain how architects utilize various types of drawings to convey the design in a format suitable for construction activities. Plans, elevations, sections, and details are the drawing types used most often to convey information required for construction. These technical drawings are typically drawn in only 2 dimensions (2D), which requires the reader to review additional drawings to understand the third dimension. This allows the architect to more easily present the information in a format that ensures nothing is concealed from view. It also systematically imposes a process of inter-related drawings that ensures that all areas of the building are properly documented. Most people are familiar with Plan Drawings. A plan, such as a floor plan, is a top down view of the layout. Imagine slicing the building horizontally 4 feet above the ground and looking directly down.
Floor plans show a lot of important information. In the example above, the contractors and builders are able to determine the length of walls, locations of doors and windows, and even the assembly of the exterior walls or interior partitions. Plan drawings may also include Enlarged Floor Plans showing more detail about a certain element of the building such as stairs. Plan drawings can also include framing plans, finish plans, electrical plans and a host of other types of plans with specific information necessary to properly document all relevant information. Plan drawings can also be "reflected" to show the ceiling condition. Earlier, we said that plan drawings are shown from 4' above the floor looking down, however; in reflected floor plans, it is from 4' looking UP. Imagine laying on the floor on your back and looking at the ceiling. This would be a reflected plan. The floor plan above is 2 dimensional. Can you determine how tall are the walls are from this view? The reader of the plan wouldn't know the answer unless they looked at other drawings. This is the limitation of 2D drawings, but one that is easily overcome by inclusion of some other familiar drawings such as Elevation Drawings. An Elevation Drawing is an interior or exterior view of the vertical elements of the structure. These drawings are the easiest for most people to understand since this is how we view the world. Standing in an upright position and viewing objects perpendicular to the ground. Unlike a 3D or perspective drawing, elevations are 2 dimensional. They don't show depth.
The drawing above represents the 2D representation of the front elevation of the building. As you can see, there is no way to tell by this drawing how far back the building extends or the distance of the projections and awnings on the front. In order to make that determination, the reader would need to view the side elevation drawing(s) or the floor plan. However, unlike the 3D drawing above, we CAN tell what the back of the building looks like by simply adding another elevation drawing to the set.
So we have now determined how tall the exterior elements of the building are by use of elevations, but how do we tell how tall interior objects are? Like exterior elevations, we can also present interior elevations. Interior elevations are the same as exterior ones, but show building elements internal to the structure. Often, interior elevations are drawn for kitchens and bathrooms to notate the height of countertops, cabinets, etc.
This interior elevation shows various kitchen appliances, base cabinets, and upper cabinets and tells the contractor exactly what height to mount building components at. This is something that is difficult to show in a floor plan drawing. This drawing also is very limited in regards to how the illustrated elements relate to the rest of the building around it. Meaning, we don't see the floor framing, the wall assembly, or any other element. Section Drawings are similar to interior elevations drawings as they show objects perpendicular to the ground. The difference is, section drawings essentially cut the building in half and view the entire construction and how the individual elements relate to each other. Section drawings are like plans, only on the vertical axis.
In the building section above, you can see the interior elements of the Women's Bathroom (Room 106), but you can also see the entire building section and how the bathroom relates to the crawlspace below it. This drawing allows the builder to understand how various elements of the building relate to each other. Lastly, do you see that square box with the 101 in it at the right side of the Section drawing? That tag (notations will be covered in a follow-up blog entry) represents a window in the wall. At the scale of section drawings, it would be impossible for a contractor to see enough detail to understand how the architect desires the window to be finished. Detail drawings are the last type of drawing we will discuss in this article. Detail Drawings can be in plan, section, or elevation views, and essentially are blown-up drawings of elements too difficult to see at smaller scales. Let's look at window 101, in section view, at the bottom section of the window.
In this detail view, we have blown up the drawing which was too small to be seen in the section drawing. By increasing the scale, we can now call out what the individual elements of the wall are and how the entire assembly is put together. The contractor should be able to build it now! Detail drawings can include a large array of additional refined information to assist the builder understand the design.