Every detailed cost estimate must start off with a highly accurate quantity take-off. In this weekly discussion, we will get into specific QTO techniques related to this week’s reading: Please discuss pertinent methodologies for executing the quantity take off function for the following activities: 1) Thermal and Moisture Protection, 2) Openings, 3) Finishes, and lastly 4) Fire Suppression… Any and all techniques of interest in these 4 areas may be discussed.
Quantity take-off (QTO) is a critical step in preparing a detailed cost estimate for construction projects. It involves accurately estimating the quantities of various materials, labor, and equipment required for each activity involved in the project. In this discussion, we will focus on the methodologies for executing the quantity take off function for activities related to thermal and moisture protection, openings, finishes, and fire suppression.
1) Thermal and Moisture Protection:
Thermal and moisture protection activities are crucial in ensuring the comfort and durability of a building. QTO for these activities involves determining the quantities of materials needed for insulation, waterproofing, and other protective measures. Some pertinent methodologies in executing the quantity take off for thermal and moisture protection include:
a) Blueprints and Specifications Analysis: A thorough analysis of the project blueprints and specifications is essential to identify the areas that require thermal and moisture protection. This analysis helps in understanding the construction details, such as wall sections and roof assemblies, which in turn aids in estimating the quantities of insulation materials and moisture barriers.
b) Material Calculation Tables: Various industry standards and manufacturer’s guidelines provide tables that help estimate the quantities of insulation materials, waterproofing membranes, and sealants based on the specified thickness, coverage area, and other parameters. Utilizing these tables can enhance the accuracy of the quantity take off process.
c) Site Visits and Historical Data: Visiting the project site and examining similar completed projects can provide valuable insights into the quantity requirements for thermal and moisture protection activities. Historical data of similar projects can be used to estimate the quantities based on past experience.
Openings in a building include doors, windows, and other access points. QTO for openings involves estimating the quantities of materials required for framing, glazing, hardware, and other components. Some methodologies for executing the quantity take off for openings include:
a) Opening Schedule Analysis: The project specifications usually contain an opening schedule that provides details about the sizes, types, and quantities of doors and windows required. Analyzing this schedule allows for an accurate assessment of the materials needed for each opening.
b) Standard Measurement Codes: The use of standardized measurement codes, such as those provided by measurement guidelines like CSI MasterFormat or SMM7, facilitates consistent and accurate quantification of materials for openings. These codes define the measurement units and methods for estimating quantities.
c) Vendor Catalogs and Pricing: Consulting vendor catalogs can be helpful in determining the quantities of specialized components, such as door hardware, hinges, and locks. Moreover, acquiring pricing information from vendors can aid in estimating the costs associated with opening materials.
Finishes include the final architectural elements that enhance the appearance and functionality of a building, such as flooring, wall finishes, and ceiling treatments. QTO for finishes requires a thorough understanding of the specified materials and their installation methods. Some methodologies for executing the quantity take off for finishes include:
a) Finish Schedules: The project specifications typically include finish schedules that detail the types and quantities of materials required for each area. Analyzing these schedules helps in accurately estimating the quantities based on the specified finishes.
b) Unit Cost Estimating: Utilizing unit cost estimating techniques enables the development of a cost estimate by assigning a unit cost to each finish item based on historical data or current market prices. This approach allows for a more comprehensive assessment of quantities and costs.
c) Estimating Software: Advanced estimation software programs can assist in automating the quantity take off process for finishes. These tools often incorporate libraries of standard finishes and their associated quantities, which can be adjusted according to the project requirements.
4) Fire Suppression:
Fire suppression systems, such as sprinklers and fire alarms, play a crucial role in ensuring the safety of occupants and protecting the building’s structure. QTO for fire suppression activities involves estimating the quantities of pipes, sprinkler heads, control panels, and other components. Some methodologies for executing the quantity take off for fire suppression include:
a) Fire Protection Design Documents: Reviewing the fire protection design documents, including drawings and specifications, is essential to understand the system layout and components involved. This analysis aids in accurately quantifying the materials required for fire suppression.
b) Manufacturer’s Guidelines: Manufacturers often provide guidelines and catalogs that specify the quantities of materials needed for fire suppression systems based on the design criteria and area classifications. Consulting these resources can enhance the accuracy of the quantity take off.
c) System Evaluation: Assessing the building’s requirements, such as occupancy type, square footage, and fire protection standards, can help estimate the quantities of fire suppression system components. Considering the specific requirements for each area helps in determining the appropriate materials and quantities.
In conclusion, executing the quantity take off function for thermal and moisture protection, openings, finishes, and fire suppression activities requires a combination of techniques. Analyzing project documents, utilizing industry standards, visiting the site, consulting vendor catalogs, and using estimation software can enhance the accuracy and efficiency of the quantity take off process.