Bill measured quantities form a critical part of a quantity surveyor’s work, providing the foundation for accurate valuation and payment of building works. They are the detailed calculations recorded on billing sheets or papers, reflecting the actual measured work on site. This chapter focuses on the preparation and use of billing sheets, the transfer of booked quantities, and the pricing of bills of quantities, all essential for effective contract management in the Kenyan construction industry.

5.1 Billing paper/sheet quantities

Billing paper or sheet quantities are the detailed records of measured work, used for interim payments and final accounts. They bridge the gap between site measurements and the formal bill of quantities, ensuring that quantities are verified and priced correctly. Accurate billing sheets enable quantity surveyors to manage project cash flow and maintain financial control.

5.1.1 Preparation of billing sheet/paper

Billing sheets are systematically prepared to capture measured quantities for each item of work. The process requires a structured approach to ensure clarity, accuracy, and traceability of measurements.

Concept and Governing Formula

Billing sheets record quantities measured on site, organized by work sections, and prepared according to standard measurement rules. There is no single formula but adherence to measurement principles such as:

• Quantities must be expressed in standard units (e.g., m², m³, number).
• Measurements are taken from drawings and site checks.
• Quantities recorded must correspond to items in the bill of quantities.

Worked Examples

Example 1: Measuring plaster area for billing
Given: A wall measures 5 m long and 3 m high. Plaster thickness is not relevant for area measurement.
Calculate the plaster area to be entered on the billing sheet.

Solution:
Area = Length × Height
= 5 m × 3 m
= 15 m²
Answer: 15 m²

Example 2: Measuring concrete volume for footing billing
Given: Footing dimensions are 2 m length, 0.5 m width, and 0.3 m depth.
Calculate the volume of concrete for billing.

Solution:
Volume = Length × Width × Depth
= 2 m × 0.5 m × 0.3 m
= 0.3 m³
Answer: 0.3 m³

Example 3: Measuring number of door frames for billing
Given: 12 door openings on site measured.
Calculate the quantity for door frames.

Solution:
Quantity = Number of door openings
= 12
Answer: 12

5.1.2 Transfer of booked quantities

Once quantities are measured and recorded on the billing sheets, they must be transferred accurately to the valuation or interim payment documents. This transfer is critical to avoid errors in payment claims.

Concept and Governing Formula

The transfer involves summing measured quantities per item and copying them into valuation sheets or interim payment forms. No formula applies, but the process includes verification steps to ensure consistency and correctness.

Worked Examples

Example 1: Summation and transfer of plaster areas
Given: Plaster areas measured in three rooms: 12 m², 15 m², and 18 m².
Calculate total plaster area to transfer.

Solution:
Total area = 12 m² + 15 m² + 18 m²
= 45 m²
Answer: 45 m²

Example 2: Transfer of concrete volumes for columns
Given: Column volumes measured as 0.5 m³, 0.7 m³, 0.6 m³.
Calculate total volume for transfer.

Solution:
Total volume = 0.5 m³ + 0.7 m³ + 0.6 m³
= 1.8 m³
Answer: 1.8 m³

Example 3: Transfer of number of windows
Given: 10 windows measured on billing sheet.
Confirm quantity for transfer.

Solution:
Quantity = 10
Answer: 10

5.1.3 Price bill of quantities

Pricing the bill of quantities involves multiplying measured quantities by appropriate unit rates to determine the value of work done. This stage is vital for preparing valuation certificates and interim payment applications.

Concept and Governing Formula

The value of work for each item is calculated using the formula:
Value = Quantity × Rate

Where:

• Quantity is the measured amount from the billing sheet
• Rate is the agreed unit cost from the contract or current market rates

Worked Examples

Example 1: Pricing plaster work
Given: Quantity = 15 m², Rate = Ksh 400/m²
Calculate the value of plaster work.

Solution:
Value = Quantity × Rate
= 15 m² × 400 Ksh/m²
= 6000 Ksh
Answer: 6000 Ksh

Example 2: Pricing concrete work
Given: Quantity = 0.3 m³, Rate = Ksh 8000/m³
Calculate the value of concrete.

Solution:
Value = Quantity × Rate
= 0.3 m³ × 8000 Ksh/m³
= 2400 Ksh
Answer: 2400 Ksh

Example 3: Pricing door frames
Given: Quantity = 12, Rate = Ksh 3500 per frame
Calculate total value.

Solution:
Value = Quantity × Rate
= 12 × 3500 Ksh
= 42000 Ksh
Answer: 42000 Ksh

Chapter Summary

This chapter covered the concept of bill measured quantities, focusing first on billing paper or sheet quantities. It detailed the preparation process of billing sheets, emphasizing accuracy and clarity to ensure correct measurement records. The transfer of booked quantities from measurement records to billing documents was explained as a crucial step for maintaining consistency. The chapter then discussed the price bill of quantities, highlighting how unit rates are applied to measured quantities to determine costs. Attention was given to emerging technologies shaping the measurement and billing process in building works. Building Information Modeling was introduced as a tool for integrated digital representation of construction data. Cloud-based collaboration platforms were described as enhancing communication and data sharing among project stakeholders. Finally, the roles of artificial intelligence, machine learning, and mobile technology were explored for improving efficiency, accuracy, and real-time data access in quantity measurement and billing.