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

IS 7922: Scope - Key Specifications & Tables

1. Scope Overview

• IS 7922 covers preferred dimensions for building components, focusing on vertical dimensions, controlling spaces, and changes in levels.
• Applies to educational buildings and general building components.

2. Preferred Dimensions for Building Components (Clause 8.1)

✔️ indicates preferred sizes.

3. Change of Level Dimensions (Clause 7.1)

4. Vertical Controlling Dimensions for Educational Buildings (Clause 14.1)

• 30 m, 36 m, 42 m

5. SI Units Used

• Length: metre (m)
• Force: newton (N) = 1 kg·m/s²
• Energy: joule (J) = 1 N·m
• Power: watt (W) = 1 J/s
• Pressure/stress: pascal (Pa) = 1 N/m²

Summary Diagram

flowchart TD
    A[Building Components

IS 7922: Field of Application – Key Points & Tables

1. Scope (Clause 1.1 & 2.2)

• Specifies multimodules and preferred vertical sizes for building components: doors, windows, built-in furniture, fixtures.
• Applies to building heights, storey, and room heights.
• Preferred vertical dimensions guide both component and overall building design.

2. Vertical Controlling Dimensions for Educational Buildings (Clause 14.1)

3. Preferred Dimensions for Building Components (Clause 8.1, Table 2)

• Dimensions are in mm, arranged in series with steps of 1m, 2m, 3m.
• Preferred sizes are marked with :selected:.

4. Units (SI Units)

• Length: metre (m)

IS 7922 - Definitions & Key Specifications

1. Controlling Dimensions (Clause 8.1, Table 2):
   Preferred heights for building components (doors, windows, furniture) are standardized in mm with three series (1M, 2M, 3M) based on controlling space steps of 100 mm, 200 mm, and 300 mm.
   Example (selected preferred sizes):

   Controlling Space (mm)	Series 1M	Series 2M	Series 3M
   100	Selected
   200		Selected
   300			Selected
   600		Selected	Selected
   900			Selected
   1200		Selected	Selected

2. Vertical Controlling Dimensions for Educational Buildings (Clause 14.1):

   • 30 m, 36 m, 42 m

3. SI Units & Definitions (IS 7922):

   • Length: metre (m)
   • Force: newton (N) = 1 kg·m/s²
   • Energy: joule (J) = 1 N·m
   • Power: watt (W) = 1 J/s
   • Pressure/Stress: pascal (Pa) = 1 N/m²

Summary Diagram (Controlling Space Series)

graph TD
    A[Controlling Space Steps] --> B[1M Series (100 mm step)]
    A --> C[2M Series (200 mm step)]
    A --> D[3M Series (300 mm step)]
    B --> E[Preferred Heights: 100, 500, 700, 1100 mm ...]
    C --> F[Preferred Heights: 200, 400, 600, 800, 1000, 1200...]
    D --> G[Preferred Heights: 300, 600, 900, 1200, 1500...]

Use these dimensions to standardize building component heights for modular coordination and design efficiency.

IS 7922: Vertical Co-ordination – General Concepts

Key Concepts:

• Controlling Zone (Clause 3.1.9):
  A vertical zone between controlling planes that governs the alignment of floors, roofs, load-bearing walls, or columns to ensure modular consistency.

• Multimodules (Clause 5.2):
  Vertical co-ordination uses multimodules of 2M and 3M, where M is the basic module dimension (commonly 100 mm or as defined).

Important Specifications:

• Basic Module (M):
  Standard unit for modular coordination (e.g., 100 mm).

• Multimodules for Vertical Coordination:

  Multimodule	Value (mm)	Application
  2M	200 mm	Typical vertical increments
  3M	300 mm	Larger vertical increments

Purpose:

• Ensures dimensional harmony in vertical building elements.
• Facilitates interchangeability and standardization in construction components.

flowchart TD
    A[Controlling Plane] --> B[Controlling Zone]
    B --> C[Floor Level]
    B --> D[Roof Level]
    B --> E[Load Bearing Walls]
    B --> F[Columns]
    G[Vertical Increments] -->|2M or 3M| B

Summary: Use 2M and 3M multimodules within controlling zones to maintain vertical modular coordination per IS 7922.

IS 7922: Preferred Vertical Dimensions Summary

Key Points:

• Preferred vertical dimensions guide the heights of building components and structural elements.
• Dimensions relate to modular heights subdividing the building horizontally and vertically.
• Main reference planes include modular storey height, room height, floor height, doorset, windowset, sill heights, etc.

Table 2: Preferred Dimensions for Height of Building Components (Clause 8.1)

Note: ✓ indicates preferred sizes.

Practical Use:

• Use these modular vertical steps to maintain uniformity and ease construction.
• Select dimensions based on the series (1M, 2M, or 3M) matching your project scale.
• Refer to Clause 4.5 for marking main reference planes on drawings.

flowchart TD
    A[Building Structure] --> B[Vertical Subdivision]
    B --> C[Modular Storey Height]
    B --> D[Modular Room Height]
    B --> E[Modular Floor Height]
   

IS 7922: Vertical Dimensions & Floor Slab Considerations

1. 5-mm Rule (Clause 6.2 & Fig. 7)

• The floor slab thickness is set 1 joint (5 mm) below the modular reference plane.
• This ensures consistent vertical alignment and tolerance control.

2. Floor Slab & Surfacing Thickness (Clause 6.4 & Fig. 8)

• Floor finishes vary widely; thickness affects:
  • Room height
  • Door heights
  • Vertical dimensions for fittings/installations
• Design vertical dimensions must be fixed considering these variations using the 5-mm rule.

3. Controlling Dimensions for Change in Floor Levels (Clause 9.1 & Table 1)

• Preferred vertical dimensions relate to modular sizes.
• Changes in floor levels should adhere to preferred modular dimensions to maintain uniformity.

4. Reference Planes (Clause 4.5 & Fig. 6)

• Identify key vertical reference planes on drawings:
  • Modular storey height
  • Modular room height
  • Modular floor height
  • Doorset/windowset heights

Summary Table: Typical Vertical Dimensions (mm)

flowchart TD
    A[Modular Reference Plane] -->|5 mm below| B[Floor Slab Top]
    B --> C[Floor Surfacing (variable thickness)]
    C --> D[Room Height (adjusted)]
    D --> E[Door Height (adjusted)]

Key takeaway: Always design vertical dimensions referencing modular planes with the 5-mm offset to accommodate floor slab and surfacing thickness variations, ensuring consistent room and door heights.

IS 7922: Key Specifications for Changes in Level (Clause 7.1 & Table 1)

• Purpose: Changes in level accommodate lofts, service pipes, Indian water-closets (squatting pans), sunken baths, etc.
• Controlling Dimensions: Preferred sizes for step heights and corresponding controlling space are given in Table 1.

Table 1: Controlling Space vs Change of Level

• M = Modular unit or reference dimension.
• Preferred sizes are marked as "selected" in the table.
• Vertical dimensions must follow the 5-mm rule for precision (Clause 6.4).

Additional Notes:

• Floor thickness variations affect room height and door heights.
• Reference plane and floor surfacing thicknesses must be accounted for (see Fig. 8 in IS 7922).

flowchart TD
    A[Change of Level Requirement] --> B{Step Height}
    B -->|20 mm| C[Controlling Space: 20 to 200 mm]
    B -->|40 mm| D[Controlling Space: 240 to 600 mm]
    C --> E[Change of Level: 1/5 M]
    D --> F[Change of Level: 2/5 M]

This ensures consistent vertical dimensions in building design per IS 7922.

IS 7922: Preferred Dimensions for Building Components (Clause 8.1 & Table 2)

• Purpose: Standardize vertical heights of components (doors, windows, furniture) based on controlling space.
• Controlling Space: The vertical module (in mm) controlling component height.
• Series: Three preferred series based on controlling space step sizes: 1M, 2M, 3M.

Key Table Extract (Preferred Heights in mm)

• Note: ":selected:" indicates preferred dimension for that series and controlling space.

Usage Guidelines:

• Refer to Clause 2.2: Apply preferred vertical dimensions primarily to building structure.
• Use Clause 9.1 for vertical subdivision of building elements.
• Select height based on controlling space and preferred series for modular coordination.

graph TD
    A[Controlling Space (mm)] --> B[1M Series]
    A --> C[2M Series]
    A --> D[3M Series]
    B --> E[Preferred Heights: 100, 500, 700, 1100 mm]
    C --> F[Preferred Heights: 200, 400, 600, 1200, 1800, 2400 mm]

IS 7922: Modular Storey and Room Heights Key Points

1. Modular Storey Height (Clause 3.1.2)

• Vertical distance between two reference planes (finished floor, rough floor, or structural floor) of consecutive floors.
• Expressed as multiples of the basic module (M).
• Typical basic module: 300 mm (0.3 m).
• Storey height = n × M (n = integer multiplier).

2. Modular Storey Height Restrictions (Clause 9.3 & 9.3.1)

• Storey heights > 30 m must follow modular floor heights as per Table 3.
• Modular storey heights must be multiples of 3 m.
• Do not combine multiples of 3 m with multiples of 2 m in the same design zone.

3. Modular Room Heights

• Selected in accordance with Table 3.
• Preferred vertical dimensions increase stepwise (Clause 5.3).
• Typical modular room heights are multiples of 300 mm.

4. Table 3 (Modular Storey and Room Heights) — Typical Values

5. Diagram: Modular Storey Height Concept

graph TD
  A[Finished Floor Level - Floor n] -->|Height = n × M| B[Finished Floor Level - Floor n+1]
  B -->|Vertical Distance| C[Modular Storey Height]
  C -->|Multiple of 3 m| D[Storey Height Limits]

Summary:

• Use 3 m multiples for modular storey height.
• Avoid mixing 3 m and 2 m multiples in controlling zones.
• Modular heights facilitate coordination and tolerance control.
• Storey heights > 30 m strictly follow modular coordination rules.

IS 7922 Key Specifications for Residential Buildings

1. Preferred Heights of Building Components (Clause 8.1, Table 2)

• Note: ✔ indicates preferred sizes for doors, windows, built-in furniture, fixtures.

2. Preferred Storey & Room Heights (Clause 9.3, Table 3)

• Note: ✔ indicates preferred storey heights for residential and related buildings.

Summary

• Use modular controlling spaces of 1M, 2M, or 3M series for component heights

IS 7922: Key Specifications for Industrial Buildings (Clause 11.1)

• Preferred vertical dimensions for industrial buildings (single/multistoreyed) are increments of 2 m and 3 m.
• Larger sizes are preferably selected from the 6 m series (e.g., 6 m, 12 m, 18 m...).

Preferred Vertical Dimensions Summary:

Practical Use:

• Design structural components (columns, beams, slabs) and building elements using these increments.
• Improves modular coordination and construction efficiency.
• Aligns with economical material use and standardized fabrication.

flowchart LR
    A[Start: Industrial Building Design]
    B[Select vertical dimension]
    C{Dimension increments}
    D[2 m series]
    E[3 m series]
    F[6 m series (for larger sizes)]
    G[Design structural elements accordingly]
    H[Achieve modular coordination]

    A --> B --> C
    C --> D
    C --> E
    C --> F
    D --> G
    E --> G
    F --> G
    G --> H

Note: Refer to IS 7922 Table 2 for detailed controlling spaces and preferred modular sizes.

IS 7922 - Health Buildings: Key Dimensions & Specifications

Preferred Vertical Dimensions (Clause 12.1)

• Vertical controlling dimensions for health buildings (in meters):
  28, 30, 32, 34, 36

Storey & Room Heights (Clause 9.3 - Table 3)

• Heights are in mm with preferred sizes marked (:selected:).
• Typical preferred room/storey heights (mm):
  • 2400, 2600, 2800, 3000, 3200, 3400, 3600, 4000, 4400, 4800, 5200, 5600, 6000, 6400, 6800, 7200, 8000, 8800, 9600, 10400, 11200, 12000
• Step increments: 2m, 3m, 4m, 6m, 8m, 12m series.

Building Component Heights (Clause 8.1 - Table 2)

• Preferred controlling spaces (mm) for components:
  100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1400, 1500, 1600, 1800, 2000, 2100, 2200, 2400
• Step increments: 1m, 2m, 3m series.

Summary Table (Preferred Heights)

Notes:

• Use larger increments (6m series) for industrial or large health buildings.
• Preferred sizes ensure modular coordination, ease of construction, and compliance with IS 7922.

flowchart TD
    A[Health Building Design] --> B[Select Vertical Dimension

IS 7922: Key Dimensions & Specifications for Office Buildings

Clause 13.1: Vertical Controlling Dimensions for Office Buildings

Preferred floor-to-floor heights (vertical controlling dimensions) are:

These dimensions ensure modular coordination and efficient space planning.

Preferred Storey and Room Heights (from Clause 9.3 & Table 3)

Notes:

• Preferred sizes are marked with a symbol (:selected:) in the code.
• These modular vertical dimensions facilitate standardization of building components and ease construction.
• Floor heights in office buildings typically range from 2.8 m to 3.6 m for functional efficiency and comfort.

graph TD
    A[Office Building] --> B[Floor-to-Floor Height]
    B --> C[2800 mm]
    B --> D[3000 mm]
    B --> E[3200 mm]
    B --> F[3400 mm]
    B --> G[3600 mm]

Summary: Use vertical modular heights of 2800-3600 mm for office buildings as per IS 7922 for effective design coordination.

IS 7922: Educational Buildings - Key Specifications

Vertical Controlling Dimensions (Clause 14.1)

• Preferred vertical heights:
  • 30 m
  • 36 m
  • 42 m

These are the modular vertical dimensions for educational buildings to ensure coordination in design and construction.

Preferred Storey & Room Heights (Referencing Clause 9.3 Table 3 for typical building heights)

Units & Definitions (SI Units)

• Length: meter (m)
• Force: newton (N) = 1 kg·m/s²
• Pressure/Stress: pascal (Pa) = 1 N/m²
• Energy: joule (J) = 1 N·m
• Power: watt (W) = 1 J/s

Summary

• Use 30m, 36m, or 42m vertical modules for educational buildings.
• Choose room/storey heights from preferred modular increments (e.g., 2400mm, 3000mm, 3600mm).
• Follow SI units for all calculations and specifications.

flowchart TD
    A[Educational Building Design]
    A --> B{Vertical Dimensions}
    B -->|30 m| C[Modular Coordination]
    B -->|36 m| C
    B -->|42 m| C
    C --> D[Room Heights]
    D --> E[2400 mm, 3000 mm, 3600 mm ...]
    C --> F[Use SI Units]
    F --> G[Force (N), Pressure (Pa), Energy (J)]

This modular approach simplifies design, construction, and integration of building components in educational facilities.