With storms and snow now being a common feature across most of the UK, we only need to watch the news to see how such bouts of bad weather can disrupt daily life.
However, no matter what season we find ourselves in, intense periods of disruptive weather are no longer confined to the winter months. In the summer of 2019 we saw the hottest summer in 140 years, bringing water shortages, melting road surfaces, and railways inoperative due to buckling lines!
These adverse weather conditions present a risk to businesses as well as individuals.
Where exceptionally adverse weather is defined in the construction contract and can be shown to have occurred, it must still be proven that this was the cause of a delay and, on some forms of contract, that the contractor has exhausted every avenue to avoid any given delay.
Again, as this is a potential source of dispute, it should be a given that good record keeping is required, and that all correct procedures of notification must be followed. With ever increasing series adverse weather to effect a contract, it is not surprising that many standard forms of contract are now taking steps to include such measures, whilst many already allow time where weather is found to impact on the programme, there is still a lack of uniformity within the industry as to what they class as adverse weather, and with that it is unlikely the contractor will be compensated for the delay.
Here we look at a few of the standard building contracts to see how each account for the risk posed by an adverse weather event and the common issues that can arise.
JCT Suite of Contracts
Under the JCT suite of contracts it only states that “exceptionally adverse weather conditions” are relevant but offers no other information as to what those conditions are.
This makes it difficult for the parties to determine if the relevant “event” has occurred, with that in mind and the difficulties it may bring it is unsurprising that some contractors look to remove adverse weather as a relevant event completely.
If the option remains within the contract, as soon as the contractor is aware that the impact of a weather event has the potential to delay the project, they are required to provide notice to the architect, contractor administrator or employer.
The notice the contractor needs to provide should include as much detail surrounding the delay as possible and provide an estimate as to the extent of the cost should a weather event occur. They may, in addition to the delay notice, serve another estimate, if the delay is to impact on the cost.
For the contractor, the difficulty will be providing enough evidence to justify an extension of time being awarded. However, to help contractors in this matter, the JCT work along side the Met Office to provide ‘JCT Met Office Weather Reports’: from these, a Downtime Report can provide useful information as it’s designed to produce specific information for specific locations, including if certain weather values are less or greater than a 1-in-10 year value.
With the need for the weather to be “exceptionally adverse” this information is very helpful in justifying the contractor’s claim.
The risk however remains and despite the assistance granted by these reports, with such a broad definition, contractors cannot be certain that any application for additional time will be accepted under the JCT contract.

NEC
Compared to the JCT suite of contracts, the NEC suite of contracts provides a comprehensive description of what constitutes an adverse weather event.
For the compensation event to be granted, the weather measurements in question must be recorded:
• Within a Calendar Month of the Compensation Event
• Before the Completion Date for the whole of the works and at the place stated in the Contract Data
Once recorded, the value is then compared with the weather data, this being the historic records of weather in the local area. Once measured and found to occur, on average, less than once in ten years, a compensation event will be found to have taken place and the relevant change in key dates will be awarded accordingly.
Under the NEC contract, it sets out that the data from the weather measurements for each month are to be based on:
• Cumulative Rainfall
• The Number of Days with Rainfall of more than 5mm
• The Number of Days with a minimum air temperature of less than 0 degrees Celsius; and
• The Number of Days with snow lying on the ground at a set time
While the NEC sets out a few weather conditions as being ‘adverse’ we note that it does not address weather conditions such as high winds or even heatwaves: contractors would need to provide evidence to the project manager showing these events occurred on average less than once in ten years.
Although adverse weather conditions are clearly set out in the NEC suite of contracts, the requirements for achieving the threshold are harder to obtain than under a JCT contract, therefore under a NEC contract, Contractors need to be very aware that they may not be awarded an extension of time or cost should an action arise.

FIDIC
Under the FIDIC Contract, it is stated that a contractor may be entitled to an extension where the delay is caused when:
• “exceptionally adverse climate conditions, which for the purpose of these Conditions shall mean adverse climatic conditions at the Site which are Unforeseeable having regard to climatic data made by the Employer…and/or climatic data published in the Country for the geographical location of the Site.”
This clause appears in the middle of the JCT and NEC directives for adverse weather, and while the definition of exceptionally ‘adverse weather climate conditions’ appears broad, it does allow for heatwaves and snowstorms to be accounted for, and requires the climate conditions to be measured against a geographical location.
The FIDIC contract again has a lower threshold than those of the JCT and NEC as the contractor is NOT obliged to provide evidence that the adverse weather occurs on average less than once in ten years.
It appears this clause hangs between being both broadly defined and quantifiable.
However, we note that under the FIDIC contract, where a delay is parallel with a delay of the contractor’s making, the extension of time entitlement shall be assessed in accordance with rules and procedures stated in the Specials Provisions, but, it is possible that due to the contractor’s own delay, even where they are entitled to an extension of time, it MAY not be awarded due to the delay of their making and the contractor should be aware of the risk when looking to apply for an extension.
Summary
What we see from these different forms of contracts is that although each one varies, it is imperative that contractors are aware of this and maintain comprehensive records in line with the contract they are under:
Are records up to date?
• Maintain and regularly update accurate records as evidence of the impact of adverse weather conditions on the programme of works.
Does your contract cover the adverse weather condition?
• Not all contracts cover all types of weather. Strict guidelines set out what adverse weather consists of, and contractors need to be aware of those restrictions: when it is necessary, an amendment can be requested to take into account the weather conditions.
Are all parts of the contract being complied with?
• Compliance within the terms of a contract particularly around notices need to be given priority as any extension of times will not be granted if not complied with.
It is almost impossible to plan for weather over the course of a project; however contractors can take measures giving them security to ensure that should an adverse weather situation arise, they are able to and find a way through to Practical Completion without too much delay or disruption.