Building Drawing and Construction Detailing
This domain tests the conventions of architectural and construction drawings: plans, elevations, sections and enlarged details, with correct line weights, symbols and annotation.
Scales and sheet content
Site and block plans at 1:1250 or 1:2500; floor plans and elevations at 1:100 or 1:50; construction details at 1:20 or 1:10. Every sheet carries a title block, drawing number, scale, north point, date and revision table. Grid lines are chain lines with circled references; levels are given as reduced levels in metres with an arrow datum symbol.
Plan conventions
Walls are cut at about 1.5 m above floor level, so windows and door openings show. Doors are drawn with the leaf and swing arc; windows show frame and glazing lines. Stairs show treads, a direction arrow and 'UP' with the number of risers. Sanitary fittings, kitchen units and services use standard symbols. Line weights distinguish cut work (thick) from projection (thin).
Section conventions
A vertical section shows foundations, hardcore, damp-proof membrane under the slab, damp-proof course in the wall at least 150 mm above external ground level, wall construction, lintels, ring beam, roof pitch and covering. Materials are hatched: brick, concrete, hardcore, earth, timber, insulation and glass each have their own pattern.
Worked example
A strip foundation detail for a 230 mm external wall: a concrete strip 600 mm wide × 200 mm deep on firm strata, two courses of blockwork to ground level, a 100 mm concrete slab on 100 mm hardcore with a DPM lapped into the DPC, DPC at 150 mm above ground, then the wall. Each element is labelled by leader line, not by a general note.
Traps
Drawing a door without a swing arc; hatching all materials identically; omitting the DPC or DPM; wrong scale stated in the title block; confusing a block plan with a site plan; leaving out the north point.