IS 7973:1976 is the Indian Standard (BIS) for architectural and building working drawings. This code of practice establishes the standards for preparing architectural and building working drawings. It covers essential aspects such as drawing sheet sizes, scales, line types, lettering, dimensioning, and the layout of title blocks, ensuring clarity and consistency in construction documentation.
Code of practice for architectural and building working drawings
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Recommended Scales (Floor Plans) | 1:50, 1:100, 1:200 | 1:50, 1:100, 1:200 are listed as preferred scales for general arrangement drawings. | AS 1100.301-2008 |
| Standard Sheet Sizes | Designation A0, A1, A2, A3, A4 (ISO 'A' Series) | Recommends ISO 'A' series of trimmed sizes (A0-A4). | ISO 7519:1991 (referencing ISO 5457) |
| Line Thickness Ratio | Recommends two thicknesses, thick and thin. The ratio of thick to thin shall not be less than 2:1. | Recommends a ratio of 2 between successive line widths of a given type. (e.g., 0.5 mm and 0.25 mm). | ISO 128-20:2020 |
| Minimum Lettering Height | Minimum height of 2.5 mm for lettering. | Minimum plotted text height of 3/32 inch (approx. 2.4 mm) for most notes and dimensions. | US National CAD Standard v6 |
| Dimension Line Termination | Arrowheads, oblique strokes, or dots. Only one style to be used on any one drawing. | Arrowheads (filled or open), oblique strokes, or dots. The chosen termination shall be used consistently on a drawing. | ISO 129-1:2018 |
| Drawing Number Discipline Code | Suggests prefixes like 'A' for Architectural, 'S' for Structural, 'P' for Plumbing. | Mandates a one or two-letter discipline designator, e.g., 'A' for Architectural, 'S' for Structural, 'P' for Plumbing. | US National CAD Standard v6 |
| Indication of North | A north point shall be shown on all plans, preferably oriented towards the top of the sheet. | A north point shall be shown on all site plans and should, wherever possible, be placed in the top right-hand corner. | AS 1100.301-2008 |