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Creating a Bill of Quantities for Construction Projects

bill of quantities for construction projects

Creating a bill of quantities for a construction project is a very important step in the planning phase. It is also one of the most important documents a contractor needs to create in order to be able to bid on the project. A bill of quantities for a construction project is important for two reasons: firstly, it can help a contractor to determine the cost of a project, and secondly, it helps the contractor to know if the project has met its budget.


Getting a construction project up and running involves a lot of planning and scheduling work. The bill of quantities is one of the most important documents. It contains a list of costs associated with each aspect of the project. However, the preliminaries section is the most challenging part to price.

The preliminaries of a bill of quantities describe the required services and facilities that will be required in the course of the contract. The description should also reflect the method of construction. It should also include a statement to the contractor.

The list of items that typically appear in a construction bill of quantities is very broad. They include plant and equipment, staff, office equipment, and general project overheads. A preliminaries list may be priced in various ways, such as a per-hour rate or a per-week cost. The prices for the individual items should be accurate and detailed.

The list of preliminaries for a construction project can include the costs of everything from the land itself to the design and planning work. If there are any issues with pricing, it can cause a big loss to the contractor.

The first and most important part of the bill of quantities is the preamble. It explains the way in which unit prices are measured. It should be an easy-to-read description of how each item was measured. It should contain only relevant points.

The second part of the preliminaries of a bill of quantity enumerates the costs for each item. The cost for each item can be approximated by using similar jobs as a yardstick. It can also be priced as a percentage of the overall cost of the project. The percentage will vary depending on the size and scope of the project.

Some of the items that are included in a construction preliminaries list are common. Generally, they are priced as a fixed cost or a per-hour rate. Other items, such as welfare facilities, are likely to be listed in an appendix of a prelims pricing schedule.


Detailed costing of a construction project starts with an itemise of the work and a Bill of Quantities. This document should be prepared according to a standard methodology. This will prevent misunderstandings and allow contractors to produce an accurate tender.

The primary purpose of the Bill of Quantities is to help the contractor in pricing the work. It is also used for planning, material scheduling, cost analysis, and post-tender work.

It helps in reducing the financial risk of a construction project. A properly defined work breakdown structure will improve financial monitoring and consultation. It will also allow for faster construction investment implementation.

A quantity surveyor will prepare a bill of quantities based on a detailed itemise of the work. The document will also contain other information including the terms of the construction contract.

A Bill of Quantities should include a list of all materials needed for the project. This will enable the contractor to keep track of the amounts that are used each month. It will also reduce the chances of any mathematical errors. The contractor will be able to price the project accurately and avoid any potential wastage.

The Bill of Quantities should be structured and categorized to ensure that they reflect the project’s scope and strategy. It is important to consider this ahead of time.

The Bill of Quantities should also account for waste during the construction process. A small mistake in the Bill of Quantities can affect the entire project. Having an accurate bill of quantities will also ensure that you get a fair system of tendering. Ultimately, it will increase the confidence of the owner.

An experienced quantity surveyor will use specialized software to measure the construction plan. The BoQ will then be sent to the selected contractor for review and pricing.

The construction project bill of quantities is usually captured in a spreadsheet format. This makes it easy to calculate the amounts and apply them to the invoice. The amount should also be reflected in subcontractor contracts.

The Bill of Quantities is one of the most important documents for a construction project. It will not only provide an accurate list of items required for the project, but will also allow for thorough evaluation and comparison of contractor proposals.


Often, construction projects are subject to a number of changes that affect the bill of quantities. The changes may be due to inflation, exchange rates, or changes in material prices. In order to avoid unnecessary cost overruns, a construction project should be well-informed about changes.

One method of documenting a modification to a construction project is to prepare a change order. This is a formal client request for a change to the work. It includes an assessment of the changes and suggests possible deductions or additions to the original contract.

In addition to providing information regarding changes, a change order can also suggest alternatives that could be more cost effective or less time-consuming than the initial plan. The document should include a list of the materials needed and the quantities required.

Generally, a bill of quantities is only prepared after the design phase. It is typically done by an engineer or quality surveyor. They are a document that provides a contractor with the materials and labor needed for a construction project. The document is used by a project manager to monitor progress and compare pricing offers. It is also used by an owner to evaluate a contractor’s proposal and to forecast cash flow needs.

The price of different items of work is based on the cost of labor and equipment. Overhead and profit are added to the item rate. However, the percentage may vary from project to project.

A bill of quantities should be created based on a standard methodology to avoid misunderstandings. It should also be broken into work sections. These sections reflect the likely sub-contract packages that the contractor might be responsible for. They should be designed to provide maximum accuracy in the price.

A bill of quantities is usually prepared by a civil engineer. It should include the unit of measurement, the quantity of the materials, and a short description of the work. It should also include the costs associated with each item. It should be returned to the owner for review.

Common mistakes made while preparing a bill of quantities

Creating a bill of quantities is a vital component of a construction project. This document provides a breakdown of materials and labour used, as well as a cost estimate for each item. It is important that these documents be prepared according to accepted standards. This prevents ambiguities and misunderstandings.

Common mistakes that can occur in a bill of quantities include omissions, inaccurate measurements, and double-counting. Inaccurate information can be attributed to a variety of reasons, including misrepresentation of information by the quantity surveyor, incorrect assumptions based on past performance, and late changes to the process.

Using a standard methodology for preparing a bill of quantities is also important. This will help avoid misunderstandings and ambiguities that can lead to disputes.

Creating a bill of quantities is primarily done by a cost consultant, often a civil engineer or quantity surveyor. They will use special software to measure the plans and materials for the project. It is important that the information is accurate and up to date, as changes can be made during the execution phase.

Some contractors make the mistake of omitting items in a BoQ. Other errors can be attributed to inaccuracy in measurements, a lack of knowledge or experience, and poor documentation of the work.

Another common mistake is in not adding a contingency sum. This sum is added to the bill of quantities to cover unexpected costs. This is usually adjusted during the execution phase.

A bill of quantities can be useful for estimating, as it gives the contractor a detailed picture of the entire project. It also helps in planning and comparing offers from contractors. It also serves as a reference for future projects.

Bills of quantities can also be used as a progress payment application and a lien waiver application. They are also useful in integrating with accounting and insurance software. This allows the owner to easily compare the quotes received and determine whether they are competitive. They can also be automated to submit paperwork to the customer’s AP process.

A bill of quantities is a vital part of the construction tendering process. It can be used to compare bids from contractors and determine the completion time of the project. The bill of quantities also serves as a communication tool between the parties involved in a construction project.