How to Accurately Estimate Commercial Construction Projects

Last updated on October 21st, 2023 at 05:22 pm

Some great tips for construction company owners provided by a professional.

How to Accurately Estimate Commercial Construction Projects

This post is a guest submission. Please see our Disclaimer, Disclosures, & Affiliate Notice for details.

Estimating is the foundation of any construction company. You can be the best salesperson out there, the best contractor out there, it all ultimately doesn’t matter if your estimate is off. Being able to know the prices and understand the project in full will determine if your bids are accepted or not, so, looking at it this way it’s clear to see that accuracy and speed in your estimating is critical. Remember that you can always outsource your takeoffs to reliable estimating firms like ours, but if you want to do the work yourself, we’ll show you how.

Let’s get right into it.

Types of Construction Cost Estimates

First things first, there are a couple different types of estimates, all with different characteristics, and some more complicated than others. They all serve their own purposes and are used in different stages of the procurement process. So, let’s begin with the earliest estimate possible, preliminary estimates.

Preliminary Estimate

These kinds of estimates are done in the early stages of a construction project to determine how much effort, materials, etc. will be needed. Since these estimates are done so early in the procurement process, the owner is only looking for a “ballpark” number to see if it’s a project they want to continue with going forward.

Detailed Estimate

These are ultra-precise measurements of the quantities of materials, equipment and manpower to build the project. It’s very, very, very important to get these right because an inaccurate estimate can lead to many problems on the job site that could have been easily avoided.

Activity Estimate

Activity estimates are basically schedules designed to provide the standard for preparing the equipment, manpower, and material estimates.This is for the managing aspect of construction, so that they have guidelines to follow so that the job can run smoothly.

Material Estimate

Material estimates consist exclusively of takeoffs of just the materials needed for the construction project. These are measured from the activity estimates, drawings, and specs. They’re sometimes referred to as “Bill of Material” (BOM), or Material Take Off.” (MTO)

Equipment Estimate

Like the Material estimates, these are limited to only the cost, amount of time, what’s needed of the equipment to be used on a construction project. These are measured from the activity estimates, drawings, specs, and info from the inspections.

Manpower Estimates

Manpower estimates consist of a specific quantity of direct labor man-days that is needed for a construction project. These are needed for efficient management of the personnel at a job, a good job of this estimate and your chances of workers and contractors alike having problems goes down by a lot.

Focus construction worker on construction site

Estimating Guidelines

So, now that you’ve seen the different types of estimating let’s get into some tips on how a proper estimate should be operated.

1. Have an organized sequence

Don’t be all over the place, if you’re estimating the roofing of a building don’t start measuring the takeoffs for the drywall before you’re even done. Finish what you start and go in the order it takes to build a house to ensure efficiency throughout the estimate.

2. Be Consistent in Listing Dimensions

Make sure you’re measuring everything by the same standard. If you measure the amount of drywall by square feet, don’t measure the insulation by square yardage or whatnot. This may seem obvious, but you’d be surprised how many times it’s led to difficulty with projects.

3. Scale Plans on Software Correctly

If you’re using digital takeoff software (which we definitely recommend), then always be sure the plans are scaled properly. Because the last thing you want is to find out after you submit your bid that you priced the drywall 3x what it actually is.

4. Copy Paste Related Quantities

This is for apartment buildings, hotels, anything with multiple rooms that are identical. To save valuable time it’s helpful to simply copy paste the same unit types onto other rooms.

5. Don’t Round Off Takeoffs Until Final Pricing

When measuring quantities, you’re going to want to wait until the end to round up numbers because if you do it during the takeoff, it’s going to get even rougher by the end of the pricing because you’d already round it off. So, in other words, just be precise when doing the takeoffs and you can round off numbers at the end.

6. Mark Takeoffs With Different Colors

This is to reduce confusion, color code things so you manage the estimate better.

7. Measure Everything Relevant to Scope

If your scope is painting, make sure to investigate every single nook and cranny to get the most accurate estimate possible if you’re bidding a job. There’s no getting around it, unless you’re outsourcing your estimating, you’re going to need to spend time doing a lot of “detective work”, as we call it around here.

8. List items Not Mentioned in Scope of Work Just in Case

Even if you think you don’t need it, it helps to have extra just in case. We’ve seen plenty of instances where an estimate was missing key structures simply because the estimator deemed it unimportant at the time, so to fix this…If you think it’s important, it probably is.

9. Develop System

There needs to be a set of principles you follow when you estimate projects, here’s an example of a basic system to complete drywall estimates:

  • Review all plans before starting work
  • Make note of where there is drywall
  • Start measuring takeoffs of drywall
  • Double check to make sure it’s correct

Systems like this one help ensure you have success with your estimating.

10. Minimize Measuring

If you measured, say, the painting of an office building for example, the average estimator may measure the walls in square feet and put that in the final estimate. But here’s a pro tip, it’s faster and more efficient to capture the linear feet of the walls and later use the height to convert it into square feet during the final pricing. You can do this with drywall and other trades as well.

Use Construction Estimating Software

We highly recommend using estimating software if you’re not already. It reduces the time needed to estimate and is much more accurate. These are some great ones for you to check out.


All in all, construction estimating is a very complex topic with so much to cover but we hope you can use what we gave you today and apply it right away to your estimating. If you want to outsource your estimating to a reliable firm dedicated to providing accuracy and punctuality, then feel free to sign up at our website submit your plans for a completely free quote. You can find us at

Owner & Founder at

Daniel started I Am Builders in 2014 and quickly turned it into one of the top Construction Estimating and Consulting Firms. The company's specialty is estimating and provides construction business consulting as part of their signature service.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top