The most accurate construction cost estimates are made by carefully reviewing blueprints and design documents. Contractors must also consider unusual project aspects such as a nonstandard floor plan, unique finishes or new materials.
An intermediate estimate called an Assembly or Systems Estimate prices work items as groups using values available in assemblies cost data guides. It also includes indirect field costs and general overhead costs.
Quantity Takeoff
A crucial step before preparing a bid, quantity takeoff involves identifying and quantifying the necessary materials required for building construction. Quantity takeoffs are based on the information provided by project documentation, including construction drawings and specifications. This process can be done manually using paper copies of the construction drawings, rulers, highlighters, digital measuring tools, and pencils, or through the use of estimating software that provides an easier way to perform a digital takeoff.
There are several advantages to conducting a thorough quantity takeoff for any construction project. For one, it helps in reducing material waste and excess inventory by providing an accurate analytical analysis of the scope activities. It also helps in optimizing material orders and establishing realistic timelines that can be adhered to, ultimately improving overall project efficiency.
While the quantity takeoff process may seem tedious and time-consuming, it’s a vital step that can be the difference between winning and losing a bid. An inaccurate or incomplete takeoff can lead to cost overruns and unnecessary delays, thereby negatively affecting the project budget, schedule, and daily workflow. Therefore, it is important to have a strong and efficient team that understands the importance of conducting thorough and accurate takeoffs. This will ensure that all the right materials are accounted for and that the final estimates accurately reflect the costs of the project.
Design Development
Design development is an exciting step for the project that links a schematic idea with a precise execution. It is critical that the architect and owner have a streamlined communication process to ensure clear decisions are made throughout this process. Additionally, the architect will need to keep long-term priorities in mind as decisions are made.
During the design development phase, the architect will work closely with engineers and other consultants to analyze systems and materials, and estimate costs. This step requires large- and small-scale decision-making, from choosing a type of mechanical system to selecting paint colors. Ideally, all ideas will be considered and integrated into the final design to save time and money during construction.
The architectural firm should also prepare a detailed pre-bid estimate during this phase. The estimate is typically organized in the same WBS as bidders are required to use, which facilitates comparison between estimates. The estimate should include the overall cost of the project, design fees, a minimal contingency, furniture and equipment, testing, surveying and other costs.
This step is also a good opportunity to involve the contractor in the bidding process. Incorporating the contractor in this phase will help to minimize estimating errors and improve the accuracy of construction documents. In addition, the contractor may provide valuable feedback on how the design can be constructed at a lower cost.
Construction Documents
Construction documents are a wide-range of drawings, specifications and data that provide a clear understanding of how a building design will be constructed. They will typically be created from the design development deliverables and must have a completed status in order for work on site to commence. This is achieved by having a 3rd party review them to ensure they meet the project/design and contract requirements. The most common construction document types are Responsibility Matrixes, Document Registers and Plant/Equipment Schedules.
Estimators will evaluate the specifications for each work package, which are a group of drawings and related specifications for the various areas of the project. This includes evaluating the structural drawings for material needs, reviewing MEP (mechanical, electrical and plumbing) drawings, assessing roof framings, analyzing finishes, and considering the potential impact of site conditions on the building construction process.
It’s important for estimators to fully understand the scope of the project in order to create a detailed estimate that meets the client’s expectations. Generally, this means conducting a site visit, making notes, taking photos and collaborating with contractors to get an accurate understanding of how the building design will be constructed on site. Estimators must also consider any unique features that may be included in the project to ensure they are providing a thorough estimate. This will help avoid any unexpected costs later on in the project.
Final Estimate
A bidding estimate is an evaluation of the cost to construct a project from the contractor’s perspective. This type of estimate is based on construction documents and the estimated building procedures devised by the contractor. Often, a building services estimator will review the bids to ensure that the prices quoted are accurate and that the contractor has taken into account all the known requirements of the project.
In the case of a complex project, there may be a number of different estimating phases during the design process that require varying levels of accuracy and detail. For example, a contractor may prepare a preliminary estimate using costs from similar projects to establish a rough budget early on in the design phase. Then, as design progresses, an engineer or architect might prepare a more detailed and accurate design development estimate. This allows the client to track forecasted budget expenditures and understand how design decisions relate to costs.
A construction management company can be especially valuable in this phase, as they can help validate that the contractor’s pricing is a reflection of actual market conditions and set appropriate client expectations. During this phase, the final estimate should also reflect a contingency factor based on the results of the risk assessment, and indirect costs such as insurance and bonding should be included in the total.