What is the basic module 'M' for modular coordination?

The basic module 'M' is 100 mm (Clause 3.1).

What is the recommended multi-module for horizontal planning?

A multi-module of 3M (300 mm) is recommended for horizontal co-ordinating dimensions (Clause 3.2).

What is a modular grid?

It is a grid in which the spacing of lines in both directions is a basic module (M) or a multi-module (Clause 2.13).

How should structural grids relate to modular grids?

Structural grids should be based on the modular grid, typically using multi-modules like 3M, 6M, or 12M for spacing columns and load-bearing walls (Clause 4.3).

IS 7921

: 1987

Recommendations for modular coordination in the building industry: Horizontal co-ordination

CurrentSpecializedGuidelinesBIMArchitectural · Planning, Housing and Pre-fabricated Construction

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This standard provides recommendations for horizontal dimensional coordination in the building industry. It establishes a system based on a basic module (100 mm) and a multi-module (300 mm) to rationalize and standardize the dimensions of buildings and their components, facilitating prefabrication and design efficiency.

Recommendations for modular coordination in the building industry: Horizontal co-ordination

Quick Reference Values

Basic Module (M)100 mm

Recommended Horizontal Multi-module3M (300 mm)

Preferred Horizontal Multi-modules (large dimensions)6M, 12M, 15M, 30M, 60M

Sub-modular incrementsM/4 (25 mm), M/2 (50 mm)

Practical Notes

The 300 mm (3M) grid is the most practical and widely adopted planning grid for setting out column lines and major building elements.

This code is foundational for pre-cast and prefabricated building systems, ensuring components from different sources can integrate.

Understanding the difference between 'co-ordinating size' (grid-to-grid) and 'work size' (actual component size) is crucial for applying this standard correctly.