Three Common Construction Scheduling Mistakes

By Lynn Pearcey, MBA, Copywriter, AIA Contract Documents

September 14, 2023

Table of Contents

  1. Introduction
  2. Ignoring the Impact of Weather
  3. Not Including a Buffer Time
  4. Overcommitting to Please a Client
  5. Conclusion


Scheduling is a crucial part of the construction process. Knowing where and when to perform a task brings a sense of order to what, from the outside looking in, appears to be utter chaos. That’s what scheduling does: It brings structure to a site and helps contractors, architects, and engineers deliver a completed project that meets all parties’ expectations. Scheduling sounds simple, but to be clear, it’s not easy, and sometimes, when a site runs awry, it’s due to mistakes in this area and the five most common are listed below.

Ignoring the Impact of Weather

Construction professionals can control many things on a site, but weather isn’t one of them. One of the most common mistakes a scheduler makes is not making allowances for weather and delays inclement weather causes. There are several different types of weather events to account for. The first one that comes to everyone’s mind is rain, snow, or ice precipitation. When any of these phenomena occur, all movements on a construction site cease. So, since you can’t control the weather, how do you manage this portion of the project? The best way to do this is to research the weather patterns of the area you’re working in. Notice the trends, when it rains, what time of the year the winds are high, and monitor the frequency of other weather events. With this information, you can schedule your project and maximize your efforts.

Not Including a Buffer Time

We don’t live in a perfect world where everything goes just as we plan, and nowhere is this more evident than on a construction site. Project managers and site leaders are encouraged to include buffer time in their schedules to remedy those imperfections. Buffer time is the extra time for a site activity that doesn’t impact the final project or other corresponding duties. So, with this in mind, the question becomes how much buffer time should be included in each project. Experts have varying beliefs, but the prevailing school of thought is to have a 200% buffer for every task time constraint. Under this principle, add four more days of buffer time to the scheduling estimate if a duty project takes two days to complete.

Overcommitting to Please a Client

If clients are pleased with contractors’ work, they’re more apt to tell others. When this happens, it opens contractors up to other opportunities that help grow their business. Overcommitting to impress is an easy marketing tactic; contractors have used it for decades to please clients. But when a contractor falls short, they’re dealing with a very unhappy client, and all of the current and future prospects are in jeopardy. Communication and honesty are the best policies for managing client expectations. Be upfront and explain the process to them so they understand all that goes into your work. Approaching a project this way helps you solidify current relationships and, most importantly, positions you to secure future projects.


If you fail to plan, plan to fail is a time-tested adage, and nowhere is it more applicable than in the wonderful world of construction. With that, review the scope of any project you’re contracted for and responsibly schedule the associated tasks. When it comes to weather, do research on the region before signing a contract. Paying attention to the weather will help you determine what to charge and also if the project is suitable for where you are in your business. Don’t be afraid to walk away based on what you find. You may lose an opportunity, but it’s better than losing your brand standing or finishing under projections.

No matter how simple a project appears to be on the surface, always be sure to include buffer time. Construction is an amazing industry, but it comes with a slew of unexpected challenges that can wreak havoc on a schedule and site. Adding buffer time protects you from these occurrences and helps ensure your project maintains scheduling integrity. Lastly, be honest with the client about the length of time it will take to complete the work you’re performing. Overcommitting sounds appealing but failing to come through on those timelines can harm your brand and any future opportunities you might be looking to secure.

Parts, people, resources, all of those things matter, but scheduling is the critical piece of the puzzle that makes them all make sense.

AIA Contract Documents has provided this article for general informational purposes only. The information provided is not legal opinion or legal advice and does not create an attorney-client relationship of any kind. This article is also not intended to provide guidance as to how project parties should interpret their specific contracts or resolve contract disputes, as those decisions will need to be made in consultation with legal counsel, insurance counsel, and other professionals, and based upon a multitude of factors.