Construction Drawing
Construction Drawing tests reading and producing plans, elevations, sections and details to scale, with correct linework, symbols and dimensions.
Drawing set
- Plan: view from above at a cut level, usually about 1 m above floor; shows walls, openings, fixtures and room labels.
- Elevation: outside face; shows levels, openings, roof profile and finishes.
- Section: cut through the building; shows foundation, floor, slab, roof and heights.
- Scale: 1:100 for plans, 1:50 for details, 1:20 or 1:10 for construction details. RF = drawing length ÷ actual length.
- Lines and symbols: continuous thick for visible outlines, dashed for hidden, chain-dotted for centre lines, thin for dimensions. Door, window, electrical and plumbing symbols must match the legend.
A good set is coordinated: plan, elevation and section agree.
Worked example
A plan is drawn at 1:100. A wall measures 45 mm on the drawing. Actual length = 45 mm × 100 = 4,500 mm = 4.5 m. At 1:50 the same wall would be 4,500 ÷ 50 = 90 mm. Always state the scale on the sheet; never scale a dimension that is already written.
Traps
Using a scale rule on a resized photocopy; mixing plan and section; leaving out the section cut line; dimensioning to the wrong face; and using hidden lines for visible edges. Check the north arrow, title block and revision cloud before issuing a drawing.