Techniques in Drawings Q7

Q.
With the aid of diagrams, explain the followings:

1. Floor plan
2. Elevations and sections
3. Scale drawings
4. Dimensions
5. Specifications

(25 marks, 2014 Q7)

A.
1. Floor Plan

In architecture and building engineering, a floor plan otherwise known as a Scottish plan is a drawing to scale, showing a view from above, of the relationships between rooms, spaces and other physical features at one level of a structure.[1]

Dimensions are usually drawn between the walls to specify room sizes and wall lengths. Floor plans may also include details of fixtures like sinks, water heaters, furnaces, etc. Floor plans may include notes for construction to specify finishes, construction methods, or symbols for electrical items.

It is also called a "plan" which is a measured plane typically projected at the floor height of 4', as opposed to an "elevation" which is a measured plane projected from the side of a building, along its height, or a section or "cross section" where a building, is cut along an axis to reveal the interior structure.

Ref:
Wikipedia search 'Floor Plan' at
http://en.wikipedia.org/wiki/Floor_plan#mediaviewer/File:Sample_Floorplan.jpg

2. Elevation and Sections

Elevation

An elevation is a view of a building seen from one side, a flat representation of one façade. This is the most common view used to describe the external appearance of a building. Each elevation is labelled in relation to the compass direction it faces, e.g. the north elevation of a building is the side that most closely faces north.[5] Buildings are rarely a simple rectangular shape in plan, so a typical elevation may show all the parts of the building that are seen from a particular direction.

Geometrically, an elevation is a horizontal orthographic projection of a building on to a vertical plane, the vertical plane normally being parallel to one side of the building.

Architects also use the word elevation as a synonym for façade, so the north elevation is literally the north-facing wall of the building.

Section drawing of the Observatorium at Potsdam.

Cross section

A cross section, also simply called a section, represents a vertical plane cut through the object, in the same way as a floor planis a horizontal section viewed from the top. In the section view, everything cut by the section plane is shown as a bold line, often with a solid fill to show objects that are cut through, and anything seen beyond generally shown in a thinner line. Sections are used to describe the relationship between different levels of a building. In the Observatorium drawing illustrated here, the section shows the dome which can be seen from the outside, a second dome that can only be seen inside the building, and the way the space between the two accommodates a large astronomical telescope: relationships that would be difficult to understand from plans alone.

A sectional elevation is a combination of a cross section, with elevations of other parts of the building seen beyond the section plane.

Geometrically, a cross section is a horizontal orthographic projection of a building on to a vertical plane, with the vertical plane cutting through the building.

Ref:

Wikipedia search 'Elevation and Section' at

http://en.wikipedia.org/wiki/Architectural_drawing

3. Scale Drawings

Plans are usually "scale drawings", meaning that the plans are drawn at a specific ratio relative to the actual size of the place or object. Various scales may be used for different drawings in a set. For example, a floor plan may be drawn at 1:48 (or 1/4"=1'-0") whereas a detailed view may be drawn at 1:24 (or 1/2"=1'-0"). Site plans are often drawn at 1" = 20' (1:240) or 1" = 30' (1:360).

In the metric system the ratios commonly are 1:5, 1:10, 1:20, 1:50, 1:100, 1:200, 1:500, 1:1000, 1:2000 and 1:5000