Loss of Efficiency and Productivity Due to
Effects of Weather
The weather—everybody watches it, talks about it, but nobody does anything about it, or so it’s said. But in the construction
industry, that’s not really the case. Most contractors take careful notice of local and regional weather patterns, the norms and
trends, and schedule their construction projects accordingly. As-planned construction schedules, prepared between the time of
estimating and the project’s startup, are almost always "weather sensitive" and are prepared to take advantage of favorable
seasonal, local, or regional weather patterns and avoid the unfavorable ones.

Thus, when a project doesn’t start on time (as scheduled or promised by the owner at bid time) or is delayed after it starts,
weather may become an all-important factor in reducing
planned productivity and efficiency. It’s much more than the
occasional abnormal or unusual weather conditions encountered on a construction project. Those things "happen," and most
construction contracts allow excusable delay time extensions—but no money—for them on a day-added-for-a-day-lost basis.

What virtually no construction contract recognizes or addresses is the shifting of entire portions of a construction project’s
work into weather conditions that are wholly unsuitable to that type of work. When the shift occurs, the contractor incurs
enormous losses in the number of extra manhours spent, additional costs, and further delays of the project and work.

The following types of weather disrupt, delay, and create efficiency and productivity losses:

Low Temperatures and Wind Chill (Cold Weather)

Worker efficiency and productivity drop as the temperature drops. The combination of low temperatures and high, sustained
winds creates a combined effect known as "wind chill." Workers who perform manual labor and move frequently from place to
place are severely effected by this factor. Under extreme wind chill conditions, efficiency and productivity can drop 50% or
greater.

The best way to quantify efficiency losses due to wind chill is by comparing productivity from wind chill-effected work periods
to that measured during normal work periods, thereby determining the difference.

In the absence of productivity measurements from daily construction record reports, the second best method for quantifying
wind chill efficiency losses is by applying tabular and formula data developed by the U.S. Army Corps of Engineers’ Cold
Weather Region Research Laboratory to project labor and equipment costs.

Use of USCOE’s methodologies only requires payroll (manhours) data and weather data (available from the NOAA weather
station closest to the project), sorted by date. The data for payroll, temperature, and wind are entered into a spreadsheet
program by date, which then uses the USCOE methodologies to calculate the weather inefficiencies and their costs. The costs
for protection from cold weather work are also considered a loss factor.

High Temperatures and Humidity (Hot Weather)

Just as labor efficiency and productivity decline in cold weather, similar losses also occur when temperatures rise above 85°F
to 100°F and beyond. The inefficiencies are quantified and claimed by actual measurement of productivity (units produced
divided by manhours expended) in hot weather (high temperatures) and comparing that measurement with normal weather
(moderate temperatures) productivity and then claiming the difference.

The combined effects of high temperatures
and high humidity levels must also be considered. A 90°F work day with a 15%
humidity level may have relatively little effect on efficiency, while an 85°F work day with 95% humidity may be very
detrimental to productivity.

Since most contractors plan projects for warmer weather in the temperate regions of the U.S., they generally do not have cause
or reason to claim hot weather efficiency losses. But even in the Southwest and Western arid regions (desert regions) and in the
Southern Gulf Coast regions, contractors usually don’t employ manual labor on very hot days or during those daily hours when
it’s the hottest and the inefficiencies are the greatest. However, when forced to work in those conditions as a result of delays,
disruptions, or interferences, the consequential efficiency losses can be claimed. Hot weather protection and safety "extras" are
also claimable.

Wind-Only Effects

In some areas, high winds, irrespective of normal temperatures and ranges, can cause unusually high efficiency losses. For
instance, blowing dust and sand can cause severe labor efficiency losses and destroy sensitive equipment and machinery.

High winds are also a severe cause of inefficiency on structural steel erection projects, particularly high-rise structures. Every
ironworker knows the old saying (paraphrased): "One hand for me and one hand for the company—until the wind blows—then
it’s both hands for me and forget the company!"

In summary, the key to weather-related claims is entitlement—whether the work shifted through the actions or behavior of
others into inefficiency and productivity losses due to unsuitable weather conditions—and, if so, how the losses can be
quantified in terms of costs (damages).

A clause in a construction contract that attempts to allocate the effects of all but "abnormal or unusual" weather conditions to
the contractor does not excuse an owner, construction manager, or design professional from responsibility for damages caused
by bad weather conditions encountered during time periods when the contractor hadn’t scheduled work to be done, but was
forced into it by noncontractor-caused delays.

Planning
around bad weather is something most contractors do very well when they bid and schedule a project. But being
pushed into bad weather is something no contractor can accommodate without added cost. However, the consequential effects
can be determined, and the costs are payable by the party that did the pushing.



Construction Claims Topics serve as guidance documents only and are written for the expressed purpose of helping
construction industry executives and supervisors learn better ways of identifying the sources and causes of
construction claims and preventing disputes.
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Copyright 2014 Meglan, Meglan & Company, Limited Columbus, Ohio