Whether you are an owner of a property or a contractor, you will want to have a clear and accurate estimation of how much a building project will cost and how long it will take before you begin. In this article, you will get an in-depth look at the basics of Construction Cost Estimate, including how it fits into the construction process and what can cause costs to rise unexpectedly. You will encounter and take a look at the major importance of estimation, best practices, pitfalls for estimators, the use of historical data, and more.
Construction cost estimating is the process of forecasting the cost of building a physical structure. Of course, builders and clients both worry about the financial impact of cost overruns and failing to complete a project. That is why they devote time and effort to estimating how much a project will cost before deciding to move forward with it. Clients considering large projects often seek multiple cost estimates, including those prepared by contractors and those calculated by independent estimators.
Project owners use cost estimates to determine a project’s scope and feasibility and to allocate budgets. Contractors use them when deciding whether to bid on a project. You usually prepare estimates with the input of architects and engineers to ensure that a project meets financial feasibility and scope requirements.
A good cost estimate prevents the builder from losing money and helps the customer avoid overpaying. It is a core component of earned value management, a project management technique that tracks a project’s performance against the total time and cost estimate.
The accuracy of a cost estimate relies on a number of things: the quality of the project plan; the level to which the estimator defines a project; the experience and skill of the estimator; the accuracy of cost information; and the quality of any tools and procedures the estimator uses.
It is practically impossible for the initial construction estimate to match the final project cost. However, this does not negate the usefulness of a comprehensive construction estimate.
Estimating assists:
Cost estimation provides the foundation for the planning of a job schedule. The accuracy of an estimate determines whether a job meets its objectives or not. Some of the benefits in cost estimation include:
All projects benefit significantly from following a deliberate and thoughtful process in cost estimation. The cost estimating process requires good judgment and planning to achieve the best results from a project. One needs to have a basic understanding of the construction process to understand the cost estimation process properly. The following steps provide a guideline when making a construction estimate:
The parties involved must agree based on cost estimation of the project before starting the estimation process. This activity entails obtaining project information such as previously developed scopes and schedules from which the estimator can come up with cost estimates. The level of the scope is always dependent on the project type, complexity, design matrix, and criteria. The cost estimator should clearly outline and document all assumptions in this stage. The cost estimator should also record additional and subsequent information to give a traceable history for each of the estimates made.
A base estimate covers all the estimated costs of a project apart from the foreseen future escalations. These estimates are usually calculated depending on different techniques such as scope definition, size, and complexity of a project. In contrast, detailed estimates vary depending on the development phase of the project. More details come to light giving a more detailed cost estimate as the design progresses. The critical inputs required in this stage are scope details, inflation rates, material take-offs, unit cost databases, and market conditions. The construction take-offs give the client an outline of the necessary material costs. Construction take-offs vary depending on the project’s size and scope.
Collecting and interpreting all scope documents can be challenging, but the project team must fix the scope documentation from the start to estimate the direct costs. The cost estimator also notes all the cautionary notes, assumptions, and exclusions while preparing the base estimate. The estimate can also be attached and included as an attachment for reference for the remaining project activities.
Reviewing the base estimate is necessary to ensure all the assumptions and basis of a project are correct. It also means that all the base cost estimates are an actual reflection of the scope of work and schedule.
It prevents the double counting of items and ensures components are not missing. This stage reviews cost-based estimates and historical data or project-specific conditions by applying the necessary location and productivity factors. The estimator also checks indirect and overhead costs with the direct costs as the basis.
An integral part of project planning is developing a risk and contingency plan. Risk management is always an ongoing process for maximizing the possibilities of opportunities and minimizing the probabilities of threats. In addition, the estimator needs to include the cost impacts of hazards in the total project costs.
Cost estimators should communicate the cost estimate data to all the necessary parties. A good communication approach determines the information that should be shared and who should receive the information.
It also determines the information channels that information should pass through. Thus, communication is just as important as numbers, and the information can be used as an effective critical tool to ensure the project’s success.
Another construction estimator should always review a cost estimate. They perform spot checks to verify quantities and costs and check the scope completeness of a project. Peer review is a crucial phase for addressing significant gaps in the estimate and an opportunity to reduce costs. Assumptions are also removed and clarified at this stage.
After this review, the estimator can now present the estimate to the management for approval. Finally, the revised estimates are reviewed by the project management staff and incorporated into the project cost baselines.
Throughout the project, the estimator continuously updates the information; they are never done with estimating the project outcome. Estimating is always a continuous process.
Estimating construction costs is one of the most important yet most neglected stages in construction. It is time-consuming, and the myriad of activities involved in construction leads many to neglect the exercise. There are different ways of estimating construction costs, as we will discuss below:
Unit cost estimating is a quick, easy and clean way of estimating construction costs. Cost estimators assign a unit cost to each component of the construction process. Setting the unit prices refines the process over time, as you can alter and modify subsequent projects for better estimates.
This method uses statistics and regression models to determine a project’s cost. It is, however, not recommended if you do not know how to use this method. It would help if you had someone on your team that explicitly does this.
Production function relates the amount built to factors such as labor and materials. To achieve a given output, you must look for the optimal input. It can be pretty accurate in estimating the input and output relations of projects.
Stick estimation is a prevalent method in cost estimation but also relatively cumbersome. One uses this method by listing every single possible cost on the job. It is an accurate estimation method but very time-consuming.
Inaccurate construction estimates are detrimental to the job in that you can quickly lose a bid, or you can win one but lose money throughout the construction process. However, there are some tips you can employ to have accurate and growing construction estimates. Below are some of the information you can use to improve your accuracy in cost estimation:
Developing a template ensures that you do not leave out anything when developing a construction estimate. Templates include all line items that are within the scope of work of the project. For example, for some subcontractors, a template can consist of materials and labor. On the other hand, the electrician’s or plumber’s template includes more items such as fixtures, controls, and transmissions. The template can also include insurance limits and administrative costs.
A review of past projects is very educational when it comes to putting up proposals. We can learn from past mistakes that help make our estimates accurate. A project of a similar size and scope is likely to have a similar construction estimate. Of course, no two projects are the same but breaking down the construction job costs enables you to evaluate the calculations more accurately. Continual improvement is impossible if you do not look where you started from.
The more accurate your take-offs are, the better your construction estimates. You can use take-off software to improve the accuracy of your take-off without having to print anything. As a result, you can determine areas and lengths more accurately within much less time. You can also break down your project into a work breakdown structure, ensuring that your project is not missing any major components. Do not, however, count every screw in the project. Instead, stick to the big stuff that matters.
Labor costs are one of the most expensive costs in a project. To make money, you need to know how productive your crew is and their completion time. Labor costs are not just the hourly wages, but they also entail the labor burden to the company. They can be summed up in indirect costs such as retirement, union contributions, tools, benefits, and more. A comprehensive labor rate sums up all these expenses. Even in the best of conditions, no two people work at the same rate. Therefore, when calculating the labor rate, you should also factor in the weather conditions, skill rate, training, and personal issues. This way, you will accurately predict the person-hours required for the project and factor it into your cost estimate.
Subcontractors in a project bid for different jobs, and you, therefore, need to dig through the proposals and see what is included and what is not. Sometimes subcontractors may miss part of their scope or omit it altogether. After skimming through the bids, you can then choose the best offer for the project. Checking other proposals is an excellent way to counter-check subcontractors’ work and ensure they do not overquote the price.
Nothing is more embarrassing than preparing a reasonable cost estimate yet riddled with mathematical errors. Check formulas on the spreadsheet or software before submitting your bids. The minor errors in calculation can accumulate into huge sums and ruin the entire estimation process.
There are many models in the industry that determine what goes into a construction estimate. However, at an abstract level, all estimates can be divided into three. These are labor, materials, and overheads and profits.
Inaccuracy in cost estimation is often a very costly mistake that results in cost overruns and blowouts in the schedule.
Labor costs are some of the most expensive yet the most difficult to estimate. Using a simple hourly rate in the labor rate can lead to huge variations. Therefore, you need to be as detailed as possible when calculating labor rates, factor in the overtime, and source data from similar projects for better accuracy.
The experienced cost estimators assess the risks and determine whether a project is feasible for their firm or not. Cost variations are common when an estimator fails to factor in the risks. The higher the probability of a threat is, the more detailed the risk analysis should be. Take note that sometimes the estimation may be okay, but a poor review of the numbers can lead to costly mistakes. In addition, time pressures can lead to errors in maths and measurements, which is why you need a standardized estimating template to help you compare and estimate correctly.
“For every minute spent on organizing, an hour is earned,” quotes Benjamin Franklin. Quite literally, for housekeepers and cleaning staff, every moment they spend executing tasks related to cleaning,…
continue reading
"Painting is the most beautiful of all arts," Paul Gauguin quotes. True enough, painting as a medium has brought eye-catching and mesmerizing works that both critics and regular admirers…
continue reading