Recommendations for modular coordination in the building industry: Location of structural walls and floor slabs
1992 Edition

Overview of Scope in IS 13613

• Coverage: Offers foundational guidance on modular coordination for placement of building components within a dimensional framework, applicable across all building types and construction methods.

• Vertical Dimensions Control: Must align with requirements in IS 7922:1987.

• Design Specifications: Detailed in Clause 6.2.

• Annex A: Enumerates relevant Indian Standards supporting IS 13613.

Reference: IS 7922:1987 Vertical Dimension Standards

• Vertical dimensions are established in multiples of 100 mm (1 MU), ensuring standardization.

Modular Coordination Framework Diagram

graph TD
    A[IS 13613 Modular Coordination] --> B[Vertical Dimensions per IS 7922]
    A --> C[Design Details (Clause 6.2)]
    A --> D[Annex A: Related Standards]
    B --> E[Standard Modular Units]
    C --> F[Component Placement & Assemblies]

IS 13613 serves as a structural basis to incorporate modular dimensions, promoting dimensional compatibility and efficient building design.

Summary of References in IS 13613

Primary Indian Standards (Clause 2.1 & Annex A)

Key Points:

• Modular coordination standards govern dimensional conformity in building design.
• Vertical and horizontal dimensions must follow IS 7922:1987 (Clause 7.1.2).
• BIS Mark usage ensures quality compliance.
• Users should verify the latest versions and amendments of these standards.

Contact and Revision Details:

• BIS Headquarters: Manak Bhavan, New Delhi
• Amendments are documented within the standard.
• Feedback references Doc No. CED 10 (4453).

Modular Coordination Simplified Concept

graph LR
A[Modular Coordination] --> B[Horizontal Coordination (IS 7922)]
A --> C[Vertical Coordination (IS 7921)]
A --> D[Application Guidelines (IS 6820)]
A --> E[Door & Window Sizes (IS 12073)]

This framework ensures uniform, repeatable building dimensions facilitating efficient design and construction.

General Design Requirements in IS 13613

Highlights from Key Clauses:

• Clause 3.1:

  • Essential conditions for jointing, foundation design, and parapet detailing in prefabricated structures.
  • Focus on compatibility, longevity, and structural soundness.

• Clauses 6.2 & 7.2:

  • Details on connections, reinforcement, and load transfer mechanisms.
  • Emphasizes anchorage, tolerance adherence, and precise dimensions.

• Clause 7.1:

  • Comprehensive structural design principles addressing safety, usability, and cost-effectiveness.
  • Considers load combinations, stability, and durability.

Important Design Elements:

• Jointing:

  • Must allow for thermal and shrinkage movements.
  • Use connectors or welding as per IS norms.

• Foundations:

  • Designed for even load distribution.
  • Account for soil bearing capacity and settlement.

• Parapets:

  • Designed to resist wind forces.
  • Secure anchorage to main structure necessary.

Sample Design Formulas:

• Load Combinations (per IS 456 & IS 13613):

  [ \text{Design Load} = 1.5 \times \text{Dead Load} + 1.5 \times \text{Live Load} ]

• Shear Strength:

  [ V_u \leq \phi V_c ]

  where (V_u) is factored shear force, (\phi) is strength reduction factor, and (V_c) is nominal shear strength.

Summary Table: Design Essentials

flowchart TD
    A[Design Essentials] --> B[Jointing Details]
    A --> C[Foundation Design]
    A --> D[Parapet Specifications]

Application Range of IS 13613

• Design of Plinth and Sub-structure Units (Clause 3.1.3):

  • Consider floor level height from reference plane.
  • Account for soil classification.
  • Select appropriate foundation type.

• Design of Parapet Units:

  • Include waterproofing and insulation.
  • Factor in parapet height.

• Vertical Dimension Controls (Clause 7.1.2):

  • Must comply with IS 7922:1987 for vertical modular coordination.

• Modular Coordination References:

  IS Number	Title
  7922:1987	Vertical Coordination
  7921:1987	Horizontal Coordination
  6820:1987	Modular Coordination Application
  4993:1983	Glossary of Terms

Summary Table: Design Factors

Modular Coordination Conceptual Diagram

graph TD
  A[Building Units] --> B[Plinth/Sub-structure]
  A --> C[Parapet Units]
  B --> D[Soil Type]
  B --> E[Foundation System]
  C --> F[Waterproofing]
  C --> G[Insulation]
  C --> H[Parapet Height]
  A --> I[Vertical Dimensions]
  I --> J[Compliance with IS 7922:1987]

For detailed modular coordination and dimension tables, consult IS 7922:1987 and related standards.

Definitions Applied in IS 13613

• Primary Reference Standards:

  • IS 4993:1983 — Glossary of Modular Coordination Terms.
  • IS 7921:1987 — Horizontal Coordination.
  • IS 7922:1987 — Vertical Coordination.

• Purpose:

  • Ensures consistent use of terms related to modular coordination, dimensions, tolerances, and component placement.
  • IS 13613 aligns terminology with these standards to maintain uniformity.

• Modular Coordination Concepts:

  • Horizontal Coordination (IS 7921) defines grid layout for horizontal component placement.
  • Vertical Coordination (IS 7922) specifies dimensioning and stacking in vertical direction.

Key Standards Table

Practical Application

• Refer to these IS codes for:
  • Terminology clarity
  • Dimensional coordination
  • Permissible tolerances
  • Component placement rules

flowchart LR
    A[IS 13613 Definitions] --> B[IS 4993:1983 Glossary]
    A --> C[IS 7921:1987 Horizontal Coordination]
    A --> D[IS 7922:1987 Vertical Coordination]
    B --> E[Standardized Terms]
    C --> F[Grid Layout & Dimensions]
    D --> G[Vertical Dimensioning & Stacking]

In brief, IS 13613 adopts definitions from IS 4993, IS 7921, and IS 7922 to guarantee consistent terminology and dimensional standards for modular coordination.

Horizontal Placement Guidelines in IS 13613

• Modular Grid Spacing:

  • Horizontal interval set at 3 meters.
  • Vertical interval set at 2 meters. (See Clause 7.1.1)

• Grid System:

  • Components are arranged on a two-dimensional grid facilitating exact location in both horizontal directions (Clause 6.1).
  • This ensures uniformity and simplifies design and assembly.

• Dimension Fixing:

  • Horizontal spacing is fixed based on technical necessities (Clause 6.3.3).
  • Placement and support of units adhere to these fixed measures.

• Vertical Reference:

  • Vertical positioning uses a single measured value from the floor plane (Clauses 7.1.1 to 7.1.5).

Grid Dimension Summary

Conceptual Diagram

graph TD
  A[Floor Level] -->|2 m Vertical| B[Component at Level 1]
  B -->|3 m Horizontal| C[Adjacent Component]
  C -->|2 m Vertical| D[Component at Level 2]

This grid system streamlines layout and structural coordination.

IS 13613: Vertical Placement Essentials

• Modular Grid Application (Clause 7.1.1):

  • Horizontal grid spacing: 3 meters.
  • Vertical grid spacing: 2 meters.
  • Vertical placement is simplified to a single distance measurement from the floor.

• Dimension Specification (Clauses 7.1.1 to 7.1.5):

  • Vertical locations are defined solely by the height above the floor level.

• Technical Fixing (Clause 6.3.3):

  • Spacing dimensions are fixed to meet technical criteria; placement and bearing are accordingly designed.

Vertical Grid Summary

Vertical Grid Diagram

graph TD
  Floor[Floor Level]
  V1[+2 m]
  V2[+4 m]
  V3[+6 m]
  Floor --> V1 --> V2 --> V3
  style Floor fill:#f9f,stroke:#333,stroke-width:2px
  style V1 fill:#bbf,stroke:#333,stroke-width:1px
  style V2 fill:#bbf,stroke:#333,stroke-width:1px
  style V3 fill:#bbf,stroke:#333,stroke-width:1px

Refer to IS 4993, IS 7921, and IS 7922 for further vertical placement standards and definitions.

Key Aspects of Structural Design in IS 13613

• Clauses 7.1 & 6.1: Horizontal structural elements should conform to a modular grid system in two axes for streamlined coordination (see Figure 2 in the standard).

• Modular Coordination: Align structural components using modular grids to facilitate compatibility and ease of construction (refer to IS 6820, IS 7921, IS 7922, IS 12073).

• Load and Stability Considerations (Clause 9.2): Design and spacing depend on:

  • Loads (dead, live, wind, seismic).
  • Material properties (concrete, steel).
  • Construction methodologies.
  • Stability and robustness demands.

Design Considerations Table

Design Formulae

• Load effect: ( E = \sum (Load \times Load Factor) )
• Design strength: ( \phi f_y A_s ) (steel), ( f_{cd} b d ) (concrete)

graph TD
    A[Modular Grid] --> B[Horizontal Structural Elements]
    A --> C[Vertical Structural Elements]
    B --> D[Load Application]
    C --> D
    D --> E[Structural Analysis]
    E --> F[Design Verification: Strength & Stability]

In essence, IS 13613 promotes modular coordination for structural layouts, emphasizing design based on loads, materials, and stability requirements.

IS 13613: External Wall Placement - Highlights

1. Modular Coordination (Clauses 8.4 & 10.1)

• External walls should be aligned with the modular grid.
• Spine walls’ inside faces are set at basic module distances (with sub-modular increments) from the grid.
• This ensures dimensional harmony with floor structures and other elements.

2. Wall Layout & Planning (Clauses 7.1.3, 7.2.3)

• Walls form a rectangular grid mesh; only essential grid lines appear on drawings.
• The '5 mm rule' (per IS 7922:1987) applies to load-bearing and partition walls for joint tolerances.
• Planning grids may be continuous or interrupted, influencing wall placement.

3. Wall Zones & Connections

• Modular wall zones align precisely with grid lines.
• Non-modular zones have walls offset from grid lines.
• Connection details vary based on grid type (continuous vs. interrupted).

Wall Placement Summary

Diagram Illustration

graph TD
    A[Planning Grid] --> B[Modular Wall Zone]
    A --> C[Non-Modular Wall Zone]
    B --> D[Wall on Modular Line]
    C --> E[Wall Offset from Modular Line]
    D --> F[Connection to Slabs (Continuous Grid)]
    E --> G[Connection to Slabs (Interrupted Grid)]

References:

• IS 7922:1987 for joint tolerances.
• Modular coordination ensures dimensional accuracy and structural stability.

For detailed figures, see IS 13613 illustrations (Fig. 2, 3, 4, 5).

Spine Wall Positioning per IS 13613

Important Clauses:

• Clause 10.1 (External Spine Walls):

  • Inside face positioned at basic module distance or sub-modular increments from planning grid.
  • See Figure 9 for placement details.

• Clause 10.3 (Internal Spine Walls):

  • Placement may be symmetrical or asymmetrical relative to grid.
  • Depends on wall thickness, opposing wall position, and modular room sizes.

• Clause 10.4:

  • Consistent spine wall locations must be maintained throughout for coordination.

• Clause 7.1.3:

  • Planning grid forms a rectangular mesh; only necessary lines are indicated on drawings.

Practical Points:

• Spine walls align with modular grid lines for systematic layout.
• Distance depends on floor component types and construction methods.
• Symmetrical placement improves stability but asymmetrical allowed for design.

Spine Wall Placement Table

Placement Diagram

graph TD
  A[Planning Grid Line] -->|Basic Module Distance| B(External Spine Wall Inside Face)
  C[Internal Spine Wall] -->|Symmetrical or Asymmetrical| D[Relative to Grid]
  B --> E[Floor Component Location]

Refer to IS 13613 Figures 7, 8, and 9 for detailed visuals.

IS 13613 Guidelines on Openings in Slabs and Walls

Alignment & Positioning (Clauses 11.1, 10.5)

• Openings (internal/external) should be positioned on space planning grid lines or basic modular grids.
• Vertical joints in spine walls must align with modular grid lines for structural integrity.

Modular Floor Planes (Clause 7.4.1)

• Three types of modular floor planes relative to coverings and slabs:
  1. Upper surface of floor covering (non-modular height).
  2. Upper surface of sub-floor (non-modular thickness).
  3. Upper surface of structural slab (non-modular thickness).

Structural Coordination (Clause 8.3)

• Floor slabs and walls require modular longitudinal and transverse dimensions.
• Thicknesses can be modular or non-modular but should correspond to continuous preferred grid lines.

Recommendations for Openings

Reinforcement Detailing Diagram

flowchart LR
    A[Slab with Opening] --> B[Reinforcement Bars Around Opening]
    B --> C[Stress Distribution]
    B --> D[Maintain Structural Integrity]

Summary: Proper positioning of openings on modular grids ensures structural strength, with reinforcement designed to manage stress concentrations effectively.

Modular Grid Adjustments in IS 13613

Key Provisions:

• Clause 10.1:

  • External spine wall inside faces are positioned at a basic module distance from grid lines; sub-modular increments allow precise adjustment (see Fig. 9).

• Clauses 6.1.1 & 6.3.2:

  • Modular grids per IS 7921:1987 are used, with grids spaced within modular lines bounding structural elements.

• Clause 12.2:

  • For odd multiples of module M or non-modular dimensions, grid lines may be shifted within neutral zones as per axial planning guidelines (IS 7921:1987).

Adjustment Formula:

[ \text{Distance from grid line} = n \times M + \Delta ]

• ( n ) = integer multiple of base module ( M )
• ( \Delta ) = sub-modular adjustment (fraction of ( M ))

Notes:

• Floor component type and orientation influence exact grid offsets.
• Grid displacement accommodates unusual column sizes or load-bearing elements without violating modular principles.
• IS 7921:1987 provides rules for axial planning and neutral zone displacement.

Conceptual Summary Table

flowchart LR
  A[Planning Grid Lines] --> B[Base Module M]
  B --> C[External Spine Wall Face]
  C --> D[Offset = n*M + Δ]
  D --> E[Adjustment for Floor Component Type]

IS 13613: Structural Beam Placement Guidelines

• Clause 13.1:

  • Beams must be positioned according to axial planning principles, centered on planning grid lines to ensure proper load transfer and alignment.

• Clause 13.2:

  • External beams align with columns and follow external wall positioning rules (Clause 9) for support and integration.

• Clause 13.3:

  • Secondary beams should also follow axial planning or be placed on basic modular grid lines to optimize size and cost.

• Clause 6.1:

  • Introduces a structural grid for horizontal components in two directions (refer Fig. 2).

Beam Positioning Summary

Axial Planning Concept

graph TD
    A[Grid Lines] --> B[Beams Centered]
    B --> C[Load Transfer to Columns]
    B --> D[Structural Alignment]

Refer to planning grid layouts (Fig. 2) for precise beam locations ensuring compliance and efficiency.

IS 13613: Modular Floor Height Essentials

1. Modular Floor Height (Clauses 7.3 & 14.4)

• Floor heights are based on the modular planning grid.
• Preferred floor height is an integer multiple of 2.0 meters.
• Includes structural slab thickness, floor finishes, ceiling, services, and occasionally beams.

2. Modular Floor Plane (Clause 8.1)

• Floor and wall components are positioned on a continuous modular grid.
• Ensures component compatibility and ease of construction.
• Applies to length, width, and thickness.

3. Typical Thickness Components

4. Floor Height Definition (Figures 6 & 10B)

• Measured between modular reference planes at upper surface of floor coverings.
• Includes base floor and structural slab.

flowchart TD
    A[Top Modular Reference Plane] --> B[Floor Finishing]
    B --> C[Structural Slab]
    C --> D[Ceiling + Services]
    D --> E[Bottom Modular Reference Plane]

Summary: Designing floor heights as multiples of 2.0 m aligns with modular grids, facilitating standardization and compatibility across building components.