Interpretation of working drawings is fundamental for quantity surveyors in Kenya to accurately measure and evaluate building works. These drawings provide detailed graphical representations of construction projects, essential for cost estimation, tendering, and contract management. A quantity surveyor must competently identify and understand different types of drawings based on their titles to ensure precise interpretation and avoid costly errors on site. This chapter focuses on developing the skill to recognize various working drawings through their titles and understand their relevance in measurement of building works.

1.1 Identify drawing based on drawing title

In the Kenyan construction industry, working drawings are categorized and titled according to their function and content. Identifying a drawing correctly from its title enables the quantity surveyor to quickly locate the specific information needed for measurement and costing. This skill reduces misinterpretations that could lead to inaccurate quantity take-offs and financial losses. The following subtopics explore the nature of drawing titles, common types of drawings encountered, the standards governing drawing titles, and practical tips for effective identification.

1.1.1 Understanding Drawing Titles

Drawing titles are concise labels that describe the content, purpose, and scope of a technical drawing. In Kenya, these titles follow conventions aligned with international and local standards such as BS 1192 and the Kenya Bureau of Standards (KEBS). A drawing title typically appears in the title block and provides essential cues for the quantity surveyor to recognize the type of information contained.

• Definition and Purpose: A drawing title succinctly indicates the subject matter, such as “Floor Plan,” “Section,” or “Electrical Layout.” This helps the quantity surveyor distinguish between structural, architectural, mechanical, or electrical drawings at a glance.
• Components of a Drawing Title: Usually includes the drawing type, project name or number, location within the project (e.g., “Ground Floor”), and sometimes scale or revision number.
• Standardization: Drawing titles conform to standards to maintain uniformity across projects. Kenyan construction projects often adopt BS or ISO standards which prescribe title block format and content.
• Role in Quantity Surveying: Correct interpretation of the title helps the quantity surveyor identify which measurements to extract, such as wall lengths from a plan or quantities of finishes from an elevation.
• Challenges: Ambiguous or incomplete titles can cause confusion, requiring the quantity surveyor to cross-check with the drawing index or consult the architect or engineer.

1.1.2 Common Types of Working Drawings and Their Titles

Quantity surveyors encounter several categories of working drawings, each with distinct titles reflecting their purpose. Understanding these enables efficient navigation through the project documents.

• Architectural Drawings: Titles include "Site Plan," "Floor Plan," "Elevation," "Section," and "Detail." These drawings show the building’s layout, appearance, and specific construction details.
• Structural Drawings: Common titles are "Foundation Plan," "Beam Layout," "Column Schedule," and "Reinforcement Details." These focus on the structural framework and materials.
• Mechanical and Electrical Drawings: Titles such as "Plumbing Layout," "Electrical Wiring Diagram," or "HVAC Plan" describe systems installations within the building.
• Civil Engineering Drawings: Include titles like "Drainage Plan," "Road Layout," and "Earthworks Section," commonly used in infrastructure projects.
• Specialist Drawings: These may have titles like "Fire Protection Layout" or "Security System Plan," addressing specific building requirements.

1.1.3 Standards Governing Drawing Titles in Kenya

Kenyan quantity surveyors rely on standardized drawing title conventions to maintain clarity and consistency across projects. Understanding these standards is critical for professional practice.

• Kenya Bureau of Standards (KEBS): Provides guidelines on technical drawing formats and title block requirements, ensuring all drawings include clear titles.
• British Standards (BS 1192): Widely adopted in Kenya, this standard prescribes drawing numbering, titling, and revision protocols to facilitate document control.
• ISO Standards (e.g., ISO 128): Offer universal principles for technical drawings, including title placement and content, supporting international project collaboration.
• Title Block Elements: Standards specify that the title block must contain the drawing title, project name, client-scale, date, drafter’s name, and revision history.
• Revision and Version Control: Drawing titles may include revision numbers or letters to indicate updates, which quantity surveyors must track to ensure measurement is based on the latest drawing.

1.1.4 Practical Tips for Identifying Drawings from Titles

Accurate drawing identification from titles requires practical skills and attention to detail in the Kenyan construction context.

• Cross-Referencing with Drawing Index: Always verify the title against the drawing index or schedule to confirm the drawing’s purpose and scope.
• Check for Scale and Revision: Titles often include the scale which informs measurement accuracy, and revision details indicating the drawing’s currency.
• Familiarize with Project-Specific Naming Conventions: Some firms or projects may use unique titles; understanding these conventions improves efficiency.
• Use of Abbreviations: Recognize common abbreviations such as “FL” for Floor Level, “Sect.” for Section, or “Det.” for Detail.
• Consult with Design Team: When in doubt, clarify with architects or engineers to avoid misinterpretation that could affect cost estimates.

Chapter Summary

This chapter focused on interpreting working drawings, starting with the ability to identify drawings accurately by their titles, which provides the initial context for the work. It then covered how to read and scale drawing dimensions correctly according to the specified units of measure, ensuring precise understanding of sizes and distances. The chapter also emphasized recognizing the geometric shapes represented in the drawings, which is essential for visualizing the building components. Additionally, it explained how to read and correlate schedules alongside the drawings to extract detailed information about materials, finishes, and quantities. Mastery of these skills enables effective measurement and planning in building works. The integration of drawing titles, dimensions, shapes, and schedules equips students with comprehensive knowledge to interpret working drawings confidently. This foundation is critical for accurate estimation and execution of construction projects.