Architectural drawing and presentation

In short

Architectural drawing is the discipline of representing three-dimensional buildings on two-dimensional sheets (and now in digital models) through agreed conventions — plans, sections, elevations, projections, perspectives and details — so that a client can understand a design and a contractor can build it without the architect present. Presentation is the layer above it: sheet composition, rendering, annotation, models and the spoken narrative that make the drawing persuasive. Every B.Arch semester examines it through studio juries, Architectural Drawing/Graphics papers and viva, and GATE (Architecture and Planning) Part A tests projection, scales, sciography and drawing conventions. In practice it decides whether a municipal sanction drawing is approved, whether a tender is priced correctly, and whether a design-competition entry is shortlisted — which is why Indian firms and government recruiters (CPWD, PWD, NBCC, HUDCO, metro rail SPVs) test drawing skills before anything else.

Explained

Classification of architectural drawings

• By stage: concept/ideation sketches → preliminary (schematic) drawings → design development → submission/sanction drawings for the local authority → working (construction) drawings → shop/fabrication drawings → as-built drawings handed over at completion.
• Presentation drawings: rendered plans, elevations, perspectives, exploded views, concept diagrams — meant to persuade a lay client or jury; scale is indicative, mood matters.
• Submission drawings: site plan, floor plans, sections, elevations, terrace plan, area statement, FAR/coverage calculation, setbacks, parking layout, rainwater harvesting and drainage details, signed by a COA-registered architect; content is fixed by the local development control regulations (DCR/UDCPR/MPD) and the National Building Code of India (NBC) 2016.
• Working drawings: fully dimensioned plans, sections, elevations, enlarged plans (toilets, kitchens, staircases), door-window schedules, reflected ceiling plans, flooring layouts, services coordination drawings, and joinery/detail drawings at 1:20 to 1:1.
• By technique: freehand sketch, hard-line manual drafting, CAD (2D), BIM (3D parametric), hybrid.

Projection systems

• Orthographic projection — parallel projectors perpendicular to the picture plane; gives true shape and size, hence used for all measured drawings. First-angle projection is the Indian/BIS convention (object between observer and plane; view from the left is placed on the right); third-angle is the US convention. Always declare which, by the projection symbol.
• Plan = horizontal section looking down, conventionally cut about 1.0–1.2 m above floor so that windows and door openings are cut through. Elevation = orthographic view of a vertical face (name it by direction faced or by compass bearing — "north elevation" means the face that looks north). Section = vertical cut; a longitudinal section runs along the long axis, a cross/transverse section across it. Show the cutting-plane line with arrows and labels (A-A, B-B) on the plan.
• Axonometric (parallel) pictorials: isometric (three axes at 120°, all scaled equally, isometric scale ratio 0.8165 ≈ 9:11 if true-length is reduced); dimetric (two axes equal); trimetric (all three different); oblique/cavalier and cabinet (front face true shape, depth receding at 30°/45°, cabinet halves the depth); plan oblique/planometric — plan rotated 30°–60° and extruded vertically, a favourite for interior and urban-block studies.
• Perspective (central) projection — projectors converge at the station point; produces the visual impression the eye receives. One-point (picture plane parallel to one set of faces — corridors, streets, interiors), two-point (vertical edges true, two sets of horizontals vanish — the standard exterior view), three-point (picture plane tilted; adds a vanishing point above or below — aerial or worm's-eye views).
• Perspective terms: ground line (GL), horizon/eye line (HL, usually 1.5–1.7 m for standing eye level), picture plane (PP), station point (SP), centre of vision (CV), vanishing points (VP), measuring line/true-height line. Cone of vision ~60° (comfortable); a station point roughly twice the object's width away avoids distortion.
• Other representations: developed surface/unfolded elevation for curved facades, exploded axonometric for assembly, reflected ceiling plan (mirror of the ceiling as if reflected on the floor), matrix/mosaic plans, collage and photomontage.

Drawing conventions, standards and sheet discipline

• Indian Standards most used: IS 962 (code of practice for architectural and building drawings), IS 696 (general engineering drawing practice) and the SP 46 drawing-practice handbook, IS 10711 (sizes of drawing sheets), IS 10713/10714 (scales and lines), IS 11669 (general principles of dimensioning), IS 8976 (graphical symbols for building drawings), IS 2053 (symbols for sanitary fittings) and IS 962's schedule of hatching/material symbols. Several older drawing-practice standards have been revised or amalgamated into SP 46 — quote a number only when you are sure of its current edition; otherwise name the subject.
• Sheet sizes (ISO A series, trimmed, mm): A0 841×1189, A1 594×841, A2 420×594, A3 297×420, A4 210×297 — each halving the previous; aspect ratio 1:√2. Add a border (typically 10 mm, 20 mm on the filing edge), a title block at the bottom right (project, client, drawing title, scale, drawn/checked by, date, drawing number, revision, architect's COA registration), north point, scale bar, legend, and a revision cloud/table.
• Standard scales: site/layout 1:1000, 1:500; master plan 1:2000 or smaller (1:5000, 1:10000); floor plans and sections 1:100 (large buildings 1:200); elevations 1:100; enlarged plans 1:50; details 1:20, 1:10, 1:5, 1:2, 1:1. Metric reductions are preferred over odd ratios; always draw a graphic scale bar because prints get resized.
• Line hierarchy (line weight = importance): cut/section outline thickest (0.7–1.0 mm), visible outlines medium (0.35–0.5 mm), hidden lines dashed, centre lines chain-thin, dimension/extension/hatching lines thinnest (0.13–0.25 mm), break lines, and property/boundary lines as long-dash-double-dot. Standard pen series: 0.13, 0.18, 0.25, 0.35, 0.5, 0.7, 1.0, 1.4, 2.0 mm (√2 progression).
• Dimensioning: chain and running (cumulative) dimensions; three dimension strings on a plan — overall, room-to-room (centre line of wall) and opening dimensions; sills, lintels, floor and plinth levels as spot levels (+0.000 FFL datum); unit stated once (normally mm) in the notes; aligned or unidirectional text, never both; arrowheads or 45° ticks used consistently.
• Lettering and annotation: single-stroke upright or sloping Gothic; heights 2.5, 3.5, 5, 7, 10, 14, 20 mm; title 7–10 mm, notes 2.5–3.5 mm; CAD text plotted height matched to scale (a 3 mm note at 1:100 is 300 mm model text).
• Material hatching: brick (diagonal 45° hatch), RCC (dots + diagonals or crosshatch), stone (irregular), earth, timber (grain), insulation, glass (thin double line), steel (blackened). Keep one hatch per material throughout a set and show it in a legend.
• Graphic furniture: north arrow, section markers, detail call-out bubbles (detail number/sheet number), door and window tags (D1, W2) keyed to a schedule, level markers, grid lines (letters one way, numbers the other), human figures and vehicles for scale.

Rendering, sciography and visual presentation

• Media: pencil (2H–6B), ink and technical pen, graded pencil tone, charcoal, pastel, watercolour wash (graded, flat, variegated), poster/gouache, marker (warm and cool greys), coloured pencil, collage; digital — raster (Photoshop), vector (Illustrator), render engines (Lumion, Enscape, V-Ray, Twinmotion, Blender).
• Rendering fundamentals: value (tonal) hierarchy before colour; three-value rule — sky, building, ground must differ in tone; texture indicates material; entourage (trees, people, vehicles, furniture) sets scale and use; foreground framing gives depth; aerial perspective (distant objects lighter, bluer, lower contrast).
• Sciography (shadow projection): the geometric construction of shade (surface turned away from light) and shadow (area cut off from light). Conventional light direction in architectural drawing is from the top-left at 45° in plan and 45° in elevation, so the shadow offset equals the projecting depth: a 600 mm chajja throws a 600 mm shadow on the wall. In true sun studies, use the site's latitude, solar altitude and azimuth with sun-path diagrams; shadow length = height / tan(altitude).
• Sheet composition: choose a grid (thirds, columns), establish one dominant image (the hero view), align drawings on common axes and a common scale where comparison matters, keep plans oriented identically across the set, leave generous negative space, and place the title block and legends consistently. Read order in India follows left-to-right, top-to-bottom; put the concept at top-left and the resolution at bottom-right.
• Physical models: study/massing models (foam board, clay, balsa), presentation models (acrylic, MDF, veneer, 3D-printed, laser-cut), site/contour models (stepped card contours), sectional and detail models. Common model scales 1:500, 1:200, 1:100, 1:50, 1:20.
• Oral presentation/jury: 3–5 minute narrative — site and context, brief and user, concept, zoning and circulation, form, materials and structure, services and sustainability, then the drawing that proves it. Answer with the drawing, not with adjectives.

Digital drafting, CAD and BIM standards

• CAD discipline: draw at full size (1 unit = 1 mm) in model space, plot to scale from layouts; one layer per element type with controlled colour/linetype/lineweight; use blocks for repeated elements, xrefs for the shared base plan, annotative or paper-space dimensions and text; plot style tables (CTB/STB) to fix pen weights; purge and audit before issue; issue PDFs, and DWG only when asked.
• Layer naming follows an agreed convention (e.g. A-WALL-EXTR, A-DOOR, A-DIMS) based on CAD-layer standards such as ISO 13567/AIA-derived systems; many Indian offices keep an in-house variant documented in a CAD manual.
• BIM: a single parametric model from which plans, sections, elevations, schedules and quantities are extracted, so they can never disagree. LOD 100–500 describes element development; IFC is the open exchange format; clash detection coordinates architecture with structure and MEP; 4D adds time, 5D cost. India's CPWD and several metro/smart-city projects now mandate BIM deliverables on large works; requirements vary by client, so check the tender's BIM execution plan.
• Limitations to state in exams: CAD/BIM speed can hide poor design thinking; renders can over-promise materials and light; freehand sketching remains the fastest design-thinking tool and is still tested in NATA/JEE Paper 2 and in studio.

Statutory, professional and legal frame

• Architects Act, 1972 and the Council of Architecture (COA) — only a registered architect may use the title "Architect"; sanction drawings carry the architect's signature, registration number and seal. COA's Minimum Standards of Architectural Education governs the B.Arch drawing syllabus; the Conditions of Engagement and Scale of Charges describe deliverables per stage.
• NBC 2016 (SP 7) — Part 1 definitions, Part 2 administration (drawings required with a building permit), Part 3 development control and general building requirements, Part 4 fire and life safety (travel distance, exit widths shown on plans), Part 8 building services; Part 2's schedule is the checklist for a submission set.
• Local rules govern the sheet: UDCPR (Maharashtra), MPD/Delhi Building Bye-laws (and the unified building bye-laws), and each state's DCR fix setbacks, FAR, ground coverage, parking and the exact submission format; many municipal bodies now accept only online submissions through auto-DCR/CAD-based plan-scrutiny systems, so drawings must follow the portal's layer and naming template.
• Accessibility: harmonised guidelines for a barrier-free built environment under the Rights of Persons with Disabilities Act, 2016 — ramps at 1:12 maximum (gentler preferred), 1500 mm turning circle, accessible toilet dimensions — must appear on submission drawings.
• Copyright: architectural drawings are "artistic works" under the Copyright Act, 1957; ownership and reuse are settled by the agreement, so retain authorship credit in the title block.

Key points

• Orthographic projection — parallel, perpendicular projectors; the only system that gives true measurable shape, hence all plans, sections and elevations.
• First-angle projection — the BIS/Indian convention; left view drawn on the right; must be declared by symbol.
• Plan cut height — a floor plan is a horizontal section taken roughly 1.0–1.2 m above the finished floor level.
• Section marker — cutting plane line with direction arrows and matching labels (A-A) placed on the plan, never only on the section.
• Isometric — three axes at 120°, equal foreshortening; isometric scale factor 0.8165 of true length.
• Oblique vs cabinet — cavalier keeps full depth, cabinet halves it to reduce apparent distortion.
• Two-point perspective — verticals stay vertical, two horizontal sets converge to two VPs on the horizon; the standard exterior view.
• Horizon line — set at eye level (1.5–1.7 m standing, ~1.1 m seated); moving it changes whether the viewer looks up or down at the building.
• Sheet sizes — A0 841×1189 mm, halving successively to A4 210×297 mm, ratio 1:√2.
• Scale — a ratio, written 1:100 and backed by a graphic scale bar because prints get resized.
• Line hierarchy — section cut thickest, visible lines medium, dimensions and hatching thinnest; weights in a √2 series from 0.13 mm.
• Dimension strings — overall, room-to-room (wall centre lines) and openings; levels as spot levels from a +0.000 datum.
• Hatching legend — one hatch pattern per material across the whole set, explained in a legend.
• Sciography — geometric shadow construction; the drawing convention is 45° light from top-left, so shadow offset equals projection depth.
• Submission vs working drawings — submission proves compliance with the DCR/NBC to the authority; working drawings tell the contractor how to build.
• BIM/LOD — one model generates coordinated drawings and schedules; LOD 100–500 grades development; IFC for exchange.
• Statutory signature — sanction drawings must be signed and sealed by a COA-registered architect under the Architects Act, 1972.
• Three-value rule — sky, building and ground must sit at distinctly different tones for a render to read.

Formulas and examples

Example 1 — Scale conversion both ways. A hall measures 12.5 m × 8.0 m and must be drawn at 1:50.

• Drawing size = 12 500/50 = 250 mm by 8 000/50 = 160 mm.
• A 7 mm long line on the same sheet represents 7 × 50 = 350 mm, i.e. 0.35 m — a 350 mm thick wall.
• If the same hall is redrawn at 1:100, it becomes 125 mm × 80 mm — a quarter of the earlier sheet area, because linear 1/2 → area 1/4.

Example 2 — Fitting a drawing to a sheet. A plot is 30 m × 45 m. Which scale fits on an A1 sheet (594 × 841 mm) with a 20 mm filing margin, 10 mm other borders and a 60 mm high title strip?

• Usable width = 841 − 20 − 10 = 811 mm; usable height = 594 − 10 − 10 − 60 = 514 mm.
• At 1:100 → 300 mm × 450 mm: fits comfortably (450 < 514), leaving room for notes.
• At 1:50 → 600 mm × 900 mm: 900 mm exceeds 811 mm, so it does not fit. Answer: draw the site at 1:100, and detail enlargements at 1:50 on a separate sheet.

Example 3 — Sciography of a chajja and a parapet. A 750 mm deep chajja sits at the head of a 1.2 m high window, i.e. 1.2 m above its sill; conventional light at 45° from the top-left.

• Shadow cast down the wall = projection depth = 750 mm, so a 750 mm band of the wall (and the top 750 mm of the window below) is in shadow — the window being 1.2 m high, the top 750 mm of glass is shaded and 450 mm is lit.
• For a real sun check in Nagpur (latitude ≈ 21.1° N) at solar noon on 21 June, solar altitude ≈ 90 − |21.1 − 23.45| ≈ 87.6°, i.e. the sun is almost overhead (its path passing just north of the zenith) — overhangs are maximally effective; on 21 December altitude ≈ 90 − 21.1 − 23.45 ≈ 45.5°, so a 4.0 m high wall throws a shadow of 4.0/tan 45.5° ≈ 3.93 m. Use site-specific sun-path data for design decisions.

Example 4 — Isometric of a plinth block. A plinth block is 3.0 m × 2.0 m × 0.9 m, drawn in isometric at 1:50.

• True-length (full-size isometric) drawing: 3000/50 = 60 mm, 2000/50 = 40 mm, 900/50 = 18 mm along the three axes — two drawn at 30° to the horizontal and the third vertical, so the axes are 120° apart on the sheet.
• Using the isometric scale: 60 × 0.8165 ≈ 49.0 mm, 40 × 0.8165 ≈ 32.7 mm, 18 × 0.8165 ≈ 14.7 mm. Both are acceptable provided the drawing states which was used; isometric-scale drawings are the geometrically exact projection.

Example 5 — Staircase and ramp for a working drawing. Floor-to-floor height 3.3 m; riser 165 mm, tread 275 mm; an accessible ramp is also needed.

• Risers N = 3300/165 = 20; in two flights of 10. Going per flight = (10 − 1) × 275 = 2475 mm.
• Check the rule of comfort: 2R + T = 2(165) + 275 = 605 mm (acceptable range ~600–640 mm); R + T = 440 mm.
• Ramp for the same 3.3 m at 1:12 = 3.3 × 12 = 39.6 m of run plus landings — impractical inside, so the lift becomes the accessible route and the ramp serves only the 600 mm plinth (600 × 12 = 7.2 m).

Where it is used

• Architectural practice: sanction sets for municipal corporations (MCGM, BBMP, GHMC, MCD), tender and GFC (good-for-construction) sets for contractors, competition entries for COA/IIA and HUDCO design competitions.
• Government and PSU roles: CPWD, state PWDs, NBCC, HUDCO, DDA/MHADA, metro rail corporations (DMRC, MMRDA, BMRCL) and smart-city SPVs recruit architects and architectural assistants who are tested on drawing standards, NBC compliance and CAD/BIM deliverables.
• Design and engineering consultancies: L&T, Tata Projects, Shapoorji Pallonji, AECOM, Jacobs, WSP and large Indian architectural firms employ draughtspersons, BIM modellers and coordinators producing IFC models and clash reports.
• Allied industries: real-estate marketing (walkthroughs, 3D renders), interior fit-out contractors (joinery details and RCPs), modular furniture and kitchen companies (shop drawings), prefab and façade fabricators (fabrication drawings at 1:5 and 1:1).
• Visualisation and media: architectural visualisation studios, game and film set design, heritage documentation (ASI and INTACH measured-drawing projects), and GIS-linked urban mapping.
• Academia and licensure: B.Arch studio juries, NATA and JEE (B.Arch) Paper 2 drawing sections, GATE Architecture and Planning, and portfolio rounds for M.Arch admissions and job interviews.

Interview questions

• Q: What exactly is a floor plan? A: A horizontal section through the building, conventionally cut about 1.0–1.2 m above the finished floor, viewed downwards — so walls are shown cut and windows and door openings appear in the cut.
• Q: How does a section differ from an elevation? A: An elevation is an orthographic view of an uncut external face; a section shows the building cut by a vertical plane, revealing internal heights, floor and roof construction, and levels.
• Q: Which projection angle is the Indian convention and how is it identified? A: First-angle projection, per BIS practice; it is identified by the truncated-cone projection symbol in the title block, and views are placed opposite to the direction of sight.
• Q: Why would you choose two-point perspective over one-point for a building exterior? A: Two-point shows two faces receding with verticals kept vertical, so it reads like a natural eye-level view of a corner; one-point suits axial spaces like corridors, streets and interiors.
• Q: What does 1:50 mean, and what is RF? A: One unit on the drawing equals 50 of the same units on the object; the representative fraction is that ratio written as a dimensionless fraction, 1/50.
• Q: Why do we still print a graphic scale bar when the scale is written? A: Because prints and PDFs get resized or photocopied; a scale bar scales with the drawing and keeps measurement valid, whereas the written ratio becomes wrong.
• Q: What is sciography and what light direction do you assume? A: The geometric construction of shade and shadow to show depth and relief; drawing convention assumes 45° light from the top-left, so a shadow offset equals the projection depth, while real design decisions use the site's solar altitude and azimuth.
• Q: How do line weights communicate information? A: They set a hierarchy — the cut outline is heaviest, visible edges medium, dimensions and hatching lightest — so the eye reads the structure of the drawing before reading its content.
• Q: What goes into a title block? A: Project and client name, drawing title and number, scale, date, drawn/checked/approved by, revision number, north point, and the architect's name with COA registration and seal.
• Q: Difference between a submission drawing and a GFC drawing? A: The submission set proves statutory compliance (FAR, setbacks, parking, fire) to the sanctioning authority at 1:100 or 1:200; the GFC set gives the contractor dimensions, levels, schedules and details at 1:50 and finer so the work can be executed and measured.
• Q: What is LOD in BIM and why does a client ask for it? A: Level of Development (100 to 500) states how reliable each element's geometry and data are at a given stage, so the client knows whether the model can be used for coordination, costing or facilities management.
• Q: A render looks stunning but the jury says the drawing fails. What is usually wrong? A: The measured drawings do not support the image — missing dimensions and levels, inconsistent scales or orientation, no section through the key space, or entourage used to hide unresolved plan and structure.

Common mistakes

• Drawing a plan as a "top view" instead of a horizontal section — windows and openings not cut, no wall thickness shown.
• Omitting the cutting-plane line, its arrows or its label on the plan, so the section cannot be located; or drawing a section that does not match the plan it claims to cut.
• Mixing scales on one sheet without labelling each drawing, and leaving out the graphic scale bar.
• Flat, uniform line weight — everything at one thickness, so section cuts, walls and dimensions read alike.
• Dimensioning carelessly: only overall dimensions, no opening or centre-line strings, missing levels and datum, units left unstated, or the same dimension repeated in two places with different values.
• Confusing first- and third-angle placement of views, and drawing isometric at true length while calling it an isometric-scale drawing.
• Placing the horizon line arbitrarily, or the station point too close, giving violently distorted perspectives; and forgetting that perspective drawings cannot be scaled.
• Submitting sanction drawings without the area statement, north point, setbacks, accessibility provisions or the architect's seal — an automatic rejection at the municipal counter.

Related topics

Architectural design principles · Interior design basics · Building construction and materials · Building services and NBC 2016 compliance · Computer-aided design and BIM · Urban design and planning