Recommendations for co-ordination of dimensions in buildings-Arrangement of building components and assemblies, Part 2: Functional group 2 External envelope

IS 7564 Part 2: Introduction & Scope - Key Points

• Scope:
  Defines co-ordinating dimensions for building components in Functional Group 2 - External Envelope.
  Emphasizes correlation of two or more products when assembled for a function (not necessarily modular coordination).

• Basic Size (Clause 2.9):
  Reference size used to fix size limits of components.

• Grading of Components (Clause 3):
  Components and assemblies are graded (A, B, C) based on precision and function.

• Table 1 (Clause 4.1):
  Provides recommended co-ordinating dimensions (Length, Width, Height, Depth, Thickness) for elements like:

  • Walls (brickwork, blockwork, lintels, RCC bands)
  • Wall openings (doors, windows, ventilators, glazing units)
  • Curtain walling components (mullions, transoms, panels)

• International Reference:
  Aligns with British Standards BSPD 6432 Parts 1 & 2 for global coordination.

Sample Extract from Table 1 (Co-ordinating Dimensions for Wall Components)

Conceptual Mermaid Diagram: Coordination of Dimensions

graph LR
  A[Building Components] --> B[Walls]
  A --> C[Wall Openings]
  B --> D[Brickwork]
  B --> E[Blockwork]
  C --> F[Windows]
  C --> G[Doors]
  D & E & F & G --> H[Co-ordinating Dimensions]
  H --> I[Length, Width, Height, Depth, Thickness]

Summary:

IS 7564 Part 2 - Scope & Key Specifications Summary

Scope (Clause 2.0, 2.9):

• Defines Basic Size as the reference size fixing limits of size for components.
• Focuses on co-ordinating dimensions for building components and assemblies, specifically for Functional Group 2 - External Envelope.

Key Points on Co-ordinating Dimensions (Clause 4.1 & Table 1)

• Co-ordinating dimensions ensure functional correlation between building components when assembled.
• Dimensions cover Length, Width, Height, Depth, Thickness of elements like walls, openings, glazing units, frames, lintels, curtain walling, etc.
• Components are graded (A, B, C) indicating dimensional tolerance and coordination level.
• Cross-references to other functional groups are provided for integrated building design.

Sample Table Extract (Recommended Dimensions for Walls and Openings)

✓ indicates recommended co-ordinating dimensions.

Important Notes

• The standard encourages correlation of dimensions rather than strict modular coordination.
• Dimensions are chosen to facilitate interchangeability and functional assembly of components.
• The grading system helps prioritize which dimensions must be strictly controlled.

flowchart LR
    A[Building Components] --> B{Functional Group 2}
    B --> C[Walls]
    B --> D[Wall Openings]
   

IS 7564 Part 2 - Key Definitions & Specifications

1. Basic Definitions (Clause 2.0 & 2.9)

• Basic Size: Reference size fixing the limits of size for components.
• Grading of Components (Clause 3.1):
  • Grade A: Essential dimensional coordination.
  • Grade B: Dimensional coordination needed in some cases.
  • Grade C: No dimensional coordination required.

2. Co-ordinating Dimensions (Clause 4.1, Table 1)

• Applies to Functional Group 2 - External Envelope.
• Dimensions include Length, Width, Height, Depth, Thickness.
• Components like walls, wall openings, glazing units, doors, windows, etc., are classified with grades A, B, or C.

3. Example from Table 1:

4. Usage

• Grade A components require strict dimensional control for proper assembly.
• Grade B components have moderate coordination needs.
• Grade C components are flexible in dimensions.

flowchart TD
    A[Building Components] --> B{Grading}
    B -->|Grade A| C[Essential Coordination]
    B -->|Grade B| D[Conditional Coordination]
    B -->|Grade C| E[No Coordination]
    C --> F[Walls, Doors, Windows]
    D --> G[Curtain Walling, Panels]
    E --> H[Hardware, Fixing Accessories]

This ensures functional compatibility and ease of assembly in building construction.

IS 7564 Part 2: Grading of Components and Assemblies & Co-ordinating Dimensions

1. Grading of Components (Clause 3.1)

• Grade A: Essential dimensional coordination (critical components/assemblies).
• Grade B: Dimensional coordination needed in some situations.
• Grade C: No dimensional coordination required.

2. Basic Size (Clause 2.9)

• Reference size used to fix limits of size for components.

3. Co-ordinating Dimensions (Clause 4.1 & Table 1)

• Applies to Functional Group 2 (External Envelope).
• Dimensions coordinated include: Length, Width, Height, Depth, Thickness.
• Example from Table 1:

• ✓ indicates dimensions requiring coordination.

4. Usage

• Use Grade A for critical load-bearing or weather-tight components.
• Grade B for secondary components.
• Grade C for non-critical parts like hardware or cramps.

flowchart TD
    A[Components/Assemblies] --> B{Grading}
    B -->|Essential| C[Grade A]
    B -->|Sometimes| D[Grade B]
    B -->|Not Required| E[Grade C]
    C --> F[Coordinate Length, Width, Height, Depth, Thickness]
    D --> G[Coordinate selectively]
    E --> H[No coordination

IS 7564 Part 2: Co-ordinating Dimensions of Building Components and Assemblies

Key Points from Clause 4.1 and Table 1 (Functional Group 2 - External Envelope)

The standard provides recommended coordinating dimensions for various building components to ensure modularity and compatibility.

Summary Table of Key Components & Coordinating Dimensions

Coordination Grades:

• A: Primary dimensions (critical for coordination)
• B: Secondary dimensions
• C: Tertiary dimensions

Practical Use:

• Use these dimensions to standardize component sizes.
• Facilitates interchangeability and ease of assembly.
• Ensures compatibility across trades and functional groups.

Visual Concept:

graph TD
    Walls -->|Length, Height, Thickness| Br

IS 7564 Part 2 — Key Specifications for Walls and Wall Components

1. Co-ordinating Dimensions (Clause 4.1, Table 1)

The standard provides recommended dimensions for building components in the external envelope (Functional Group 2). Key elements include:

(✓ = recommended dimension coordination)

2. Notes on Dimensions:

• Thickness is critical for damp proof courses, lintels, RCC bands.
• Height and Width are coordinated for wall openings (windows, doors).
• Length and Height are important for brick/block walls.
• Cross references indicate related functional groups for integration.

3. General Recommendations:

• Use modular coordination for bricks and blocks to ensure dimensional compatibility.
• Allow for standard sizes in lintels and RCC bands to facilitate prefabrication.
• Ensure wall openings comply with coordinated dimensions to fit standard door/window units.

Diagram: Coordination of Wall Components

graph TD
    Walls --> Brickwork
    Walls --> Blockwork
    Walls --> DampProofCourse
    Walls --> Lintels
    Walls --> RCCBands

IS 7564 Part 2 - Wall Openings (Doors & Windows) Key Specifications

1. Co-ordinating Dimensions (from Table 1, Clause 4.1)

• Grade A components are primary for external envelope.
• Thickness for frames and door leaves is critical for fitting and structural integrity.
• Dimensions marked "1/" or "1.0" indicate standard modular units or thickness in inches.

2. Important Notes:

• Doorsets include various types: side-hung, sliding, folding, revolving, roller shutters.
• Wall openings must coordinate with lintels, sills, and glazing units for structural and functional integration.
• Hardware and fixings are Grade C, usually not dimension-critical but essential for assembly.

3. Practical Design Tips:

• Use modular coordination: door/window widths and heights in multiples of standard brick/block sizes.
• Ensure lintel depth matches wall thickness plus opening width.
• Allow clearance for ventilation grilles and roller blinds as per functional requirements.

flowchart LR
    A[Wall Opening] --> B[Door Frame]
    A --> C[Door Leaf]
    A -->

IS 7564 Part 2: Roofs and Roof Openings - Key Points

This part focuses on coordinating dimensions for external envelope components, including roofs and roof openings.

1. Co-ordinating Dimensions (from Table 1)

• Length, Width, Height, Depth, Thickness are standardized for components to ensure modularity.
• Roof openings include:
  • Ventilators
  • Skylights
  • Roof hatches
  • Flashings
  • Fixing accessories

2. Key Specifications:

• Roof openings must align with structural and drainage components (Functional Group 1 & 4).
• Thickness and depth depend on roofing material (e.g., corrugated sheets, insulating sheets).
• Ventilators and glazing units should have coordinated frame sizes for ease of installation.
• Flashings and fixing accessories must be compatible with roof slope and material.

3. Typical Dimension Coordination:

4. General Formula for Roof Opening Size:

[ \text{Opening Size} = \text{Standard Module} \times n ]

Where n is an integer to maintain modular coordination.

5. Coordination Diagram

graph TD
    A[Roof Structure] --> B[Roof Covering]
    B --> C[Roof Openings]
    C --> D[Ventilators]
    C --> E[Skylights]
    C --> F[Roof Hatches]
    C --> G[Flashings]
    C --> H[Fixing Accessories]
    A --> I[Drainage Components]
    I --> G

Summary: IS 7564 Part 2

IS 7564 Part 2 - Key Specifications for Curtain Walling & Facing Materials

1. Co-ordinating Dimensions (Clause 4.1, Table 1)

2. Key Notes:

• Grade A: High precision coordination for external envelope components.
• Curtain wall components require precise width, height, and thickness coordination.
• Mullion and transom sections have specified dimensional coordination for seamless assembly.
• Facing materials coordinate in length, width, and height for uniform cladding.
• Glazing units demand edge sealing and dimensional accuracy for weather-tightness.

3. Practical Application:

• Use these dimensions as a design baseline for modular coordination.
• Ensure curtain wall mullions and transoms conform to specified thickness for structural integrity.
• Panels and facing materials should align with these dimensions to avoid installation issues.

flowchart LR
    A[Facing Materials] --> B[Curtain Wall Mullions]
    B --> C[Transom & Sill Sections]
    C --> D[Infill Panels]
    D --> E[Glazing Units]
    E --> F[Complete Curtain Wall Assembly]

This coordination ensures functional and aesthetic integration of curtain walling and facing materials in the building envelope per IS 7564 Part 2.

IS 7564 Part 2: Co-ordinating Planes and Spaces – Key Points

Definitions (Clauses 2.6 to 2.8)

• Co-ordinating Plane: Reference plane to align building components.
• Co-ordinating Space: Volume bounded by co-ordinating planes, including tolerance and joint clearances.
• Co-ordinating Dimensions: Dimensions within co-ordinating space defining relative positions of components for proper assembly.

Key Specifications

• Dimensional co-ordination is critical for length, width, and height/thickness.
• Co-ordination is component-specific, based on assembly requirements.
• Allowances for tolerances and joint clearances must be incorporated in co-ordinating spaces.

Practical Approach

1. Identify components requiring dimensional co-ordination.
2. Define co-ordinating planes for each component interface.
3. Allocate co-ordinating spaces with tolerances.
4. Use co-ordinating dimensions to ensure fit and function.

Typical Co-ordinating Dimension Formula:

[ \text{Co-ordinating Dimension} = \text{Nominal Dimension} + \text{Tolerance} + \text{Joint Clearance} ]

Example Table: Typical Allowances for Co-ordinating Space

flowchart LR
    A[Component 1] -->|Co-ordinating Plane| B[Co-ordinating Space]
    B -->|Dimension| C[Component 2]
    B -->|Tolerance + Clearance| D[Assembly Fit]

Summary: IS 7564 Part 2 emphasizes defining reference planes and spaces with appropriate dimensional allowances to ensure proper assembly and function of building components.

IS 7564 Part 2: Tolerances and Joint Clearances Summary

Key Definitions:

• Co-ordinating Space (Clause 2.7): Space allocated to a component including tolerances and joint clearances.
• Basic Size (Clause 2.9): Reference size from which limits of size are fixed.

Tolerances & Joint Clearances:

• Tolerances depend on grading of components (Grade A, B, C).
• Joint clearances ensure proper fit and accommodate manufacturing/installation deviations.

Recommended Co-ordinating Dimensions (Table 1 Highlights):

• Grade A: Highest accuracy (e.g., door/window frames, glazing units).
• Grade B: Moderate accuracy (e.g., bricks, blocks).
• Grade C: Lower accuracy (e.g., handrails, cramps).

Practical Notes:

• Allowances for joint clearances vary by component and assembly grade.
• Dimensions for length, width, height, depth, and thickness are coordinated to ensure functional fit.
• Cross-reference other functional groups for drainage, structural, and finishing components.

flowchart LR
    A[Basic Size] --> B[Co-ordinating Space]
    B --> C[Tolerances]
    B --> D[Joint Clearances]
    C & D --> E[Final Component Dimensions]

Use Table 1 from Clause 4.1 for detailed dimension coordination and tolerance grading for external envelope components.

IS 7564 Part 2 (1989) – Functional Group 2: External Envelope
Key Cross-References & Coordinating Dimensions

Overview

• Clause 4.1 provides Table 1 with recommended coordinating dimensions for building components of the external envelope.
• The table aligns elements of construction with their assemblies, components, grading, and dimensional coordination (Length, Width, Height, Depth, Thickness).
• It includes cross-references to other functional groups for integrated design.

Important Elements & Cross-References (Summary)

Dimensional Coordination Highlights

• Length, Width, Height, Depth, Thickness are coordinated per component to ensure modularity and compatibility.
• Grades A, B, C indicate priority or type of coordination (A = primary, B = secondary, C = tertiary).
• Cross-references ensure components like damp proof courses (Group 1 & 3) and drainage elements (Group 4) are integrated.

Practical Use

• Use Table 1 to select coordinating dimensions for external envelope elements.
• Refer to cross-functional groups for related structural (Group 1), finishing (Group 3), or drainage (Group 4) details.
• Ensures seamless integration of building components across disciplines.

flowchart TD
    A[External Envelope Components]

IS 7564 Part 2: Application of Modular Coordination Principles

Key Concepts:

• Modular Coordination means correlating dimensions of building components so they fit together functionally.
• The standard divides building components into 5 functional groups:
  1. Structure
  2. External envelope
  3. Internal subdivision
  4. Services and drainage
  5. Fixtures, furniture, and equipment

Grading of Components for Coordination (Clause 3.1):

Application Steps:

1. Decide if coordination is functionally necessary.
2. Assign components to functional groups.
3. Grade components A, B, or C based on coordination need.
4. Use coordination to define nominal and working sizes for components.

Reference Standards:

• BSPD 6432 Part 1 & 2 (British Standards on coordination in building components)
• Indian Standards series on modular coordination (for detailed dimensional tables)

Summary Diagram:

flowchart TD
    A[Start: Identify Building Components] --> B{Is Coordination Needed?}
    B -- Yes --> C[Assign Functional Group (1 to 5)]
    C --> D[Grade Component (A, B, or C)]
    D --> E[Define Nominal & Work Sizes]
    B -- No --> F[No Coordination Required]

For detailed dimensional tables and nominal sizes, refer to IS 7564 Part 2 annexures and related modular coordination IS codes.

IS 7564 Part 2: References and Related Standards - Key Points

1. Purpose:

• Establishes co-ordinating dimensions of building components for Functional Group 2 - External Envelope.
• Emphasizes co-ordination of dimensions (not just modular coordination) for functional integration.

2. Key Reference Standards Used:

• BSPD 6432 Part 1 & 2 (1969): British Standards on coordination of building dimensions within functional groups.
• Indian modular coordination standards series (details on page 10 of the standard).

3. Important Table (Clause 4.1 - Table 1):

• Provides recommended co-ordinating dimensions (Length, Width, Height, Depth, Thickness) for elements like:
  • Walls (brickwork, blockwork, lintels, RCC bands)
  • Wall openings (doors, windows, ventilators, glazing units)
  • Curtain walling components (mullions, transoms, panels)
  • Other external envelope components (louvers, grilles, handrails)

4. Coordination Concept:

• Dimensions are coordinated to ensure functional compatibility when components are assembled.
• Cross-reference to other functional groups (e.g., structural, drainage) is provided.

Sample Extract from Table 1 (Co-ordinating Dimensions for Walls & Openings)

Summary Diagram: Coordination Flow

graph LR
A[Building Components] --> B[Functional Group 2 - External Envelope]
B --> C[Walls]
B --> D[Wall