Quantity Takeoff Methods: Long Wall, Short Wall & Centre Line

Introduction

Quantity takeoff means measuring volumes and areas from drawings to arrive at material quantities. For buildings, earthwork, foundation concrete, brickwork in plinth and superstructure can be worked out by two main methods:

1. Long wall – short wall method
2. Centre line method
3. Partly centre line and partly long wall–short wall

This guide explains each method with a worked example for a single-room load-bearing structure.

Long Wall – Short Wall Method

Definitions

• Long wall – Wall along the length of the room
• Short wall – Wall perpendicular to the long wall

How to Get Lengths

1. Find centre line lengths of each wall.
2. Long wall (out to out) = Centre line length + (½ × breadth) at each end
3. Short wall (in to in) = Centre line length − (½ × breadth) at each end

As you move from earthwork → foundation → footings → basement → superstructure:

• Long wall length decreases (breadth reduces)
• Short wall length increases

Quantity = Length × Breadth × Height (or depth).

Example: Single Room 5.3 m × 4.3 m (internal)

Assume:

• Foundation width: 0.9 m, depth: 1.4 m (0.3 + 0.5 + 0.6)
• CC bed: 0.9 m × 0.3 m
• RR masonry footings: 0.6 m × 0.5 m
• RR masonry basement: 0.45 m × 0.6 m
• Brickwork superstructure: 0.30 m × 3.0 m

Centre line length = 2 × (5.3 + 4.3) = 19.2 m

Earthwork excavation:

• Long wall L = 5.3 + 0.45 + 0.45 = 6.2 m
• Short wall L = 4.3 − 0.45 − 0.45 = 3.4 m
• Q = 2 × 6.2 × 0.9 × 1.4 + 2 × 3.4 × 0.9 × 1.4 = 24.192 cum

CC (1:4:8) bed:

• Q = 2 × 6.2 × 0.9 × 0.3 + 2 × 3.4 × 0.9 × 0.3 = 5.184 cum

RR masonry footings:

• Long wall L = 5.3 + 0.3 + 0.3 = 5.9 m
• Short wall L = 4.3 − 0.3 − 0.3 = 3.7 m
• Q = 2 × 5.9 × 0.6 × 0.5 + 2 × 3.7 × 0.6 × 0.5 = 5.76 cum

RR masonry basement:

• Long wall L = 5.3 + 0.225 + 0.225 = 5.75 m
• Short wall L = 4.3 − 0.225 − 0.225 = 3.85 m
• Q = 2 × 5.75 × 0.45 × 0.6 + 2 × 3.85 × 0.45 × 0.6 = 5.184 cum

Brickwork superstructure:

• Long wall L = 5.3 + 0.15 + 0.15 = 5.6 m
• Short wall L = 4.3 − 0.15 − 0.15 = 4.0 m
• Q = 2 × 5.6 × 0.30 × 3.0 + 2 × 4.0 × 0.30 × 3.0 = 17.28 cum (before door/window deductions)

Centre Line Method

When to Use

Suitable when walls have similar cross-section. Total centre line length × breadth × depth gives quantity in one step.

Junction Adjustment

Where cross walls or partitions join the main wall, reduce centre line by half the breadth for each junction.

Total centre line = sum of all walls − (½ × breadth) × number of junctions

Same Example by Centre Line

Centre line length = 2(5.3 + 4.3) = 19.2 m (no internal walls)

Earthwork excavation:

• Q = 19.2 × 0.9 × 1.4 = 24.192 cum

CC bed:

• Q = 19.2 × 0.9 × 0.3 = 5.184 cum

RR masonry footings:

• Q = 19.2 × 0.6 × 0.5 = 5.76 cum

RR masonry basement:

• Q = 19.2 × 0.45 × 0.6 = 5.184 cum

Brickwork superstructure:

• Q = 19.2 × 0.30 × 3.0 = 17.28 cum

Same answers as long wall–short wall, with less calculation.

Partly Centre Line and Partly Long Wall–Short Wall

Use when:

• External walls – Same thickness all around → centre line method
• Internal walls – Different thickness or levels → long wall–short wall method

This is common in practice for buildings with different foundation levels or wall thicknesses.

Choosing a Method

Situation	Preferred method
Simple rectangular room, same section	Centre line
Multiple rooms, different wall thicknesses	Long wall–short wall or partly centre line
Symmetrical layout	Centre line
External + internal with different sections	Partly centre line

Deductions for Openings

For brickwork in superstructure, deduct door and window openings:

Deduction = Opening length × Wall thickness × Opening height

Deduct lintel volume separately if required. Net brickwork = Gross − Deductions.

Next Steps

• Detailed Estimates of Buildings – Full measurement and abstract for single/double room buildings
• Brick, Cement, Sand for 10×10 Room – Practical material calculation