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Fainche Whelan | 14th March 2023

How does my Construction Contract deal with adverse weather?


Fainche Whelan | 14th March 2023

How does my Construction Contract deal with adverse weather?

It is important to make sure your construction contract deals with “adverse weather” suitably.

According to a Taylor & Francis study, adverse and unpredictable British weather can delay and extend construction projects by 21%. Strong winds can prevent work at height, on roofs or with cranes, damage existing works and even collapse scaffolding in extreme cases. Rain, snow and hail will likely prevent progress on electrical works, cause access problems for heavy machinery, affect concreting and can cause flooding on poorly-drained sites. Conversely, unusually hot and cold weather brings about health and safety concerns for workers, having to take additional precautions (such as additional PPE and taking additional breaks) to stay safe.

Disruptions on the roads, at ports and on railways can also cause delays for suppliers delivering goods to sites, or prevent staff from accessing sites.

For employers, contractors and other construction professionals alike, all of this materialises in not only delays, but also potentially steep costs in terms of materials, equipment and managing project budgets effectively.

Standard Construction Contracts and adverse weather

What is “adverse weather” and who is responsible for weather-based delays?  Below, we set out what standard form construction contracts say.

The general rule is that if the construction contract is silent on weather delays then these will be the contractor’s responsibility. To counteract this, many contracts will identify adverse weather within the extension of time provisions as an employer risk event.

JCT Construction Contracts

The JCT suite of contracts list “exceptionally adverse weather conditions” as a Relevant Event, which would entitle a contractor to an extension of time under the contract. When un-amended, JCT Design & Build Contracts place the risk of adverse weather on the employer.

However, the term “exceptionally adverse weather conditions” is not defined and so the contract is silent on what this means. Therefore, parties either choose to remove this Relevant Event or look to define it themselves. The little case law there is on the subject states that adverse weather must mean that it is “exceptional”, (which will mean assessing the weather over a period of time and looking at what exceeds the average, depending on length of time and location). If the contractor believes it is “reasonably apparent” that the Works could be delayed by adverse weather, they are obliged to give notice of this delay immediately.

In a practical context, it is up to the contract administrator/employer’s agent (depending on the type of JCT contract used), to determine whether this criterion is met. JCT offers a range of resources, namely location-specific Weather Planning Reports and Downtime Reports, which value different weather elements over a 1-in-10 year or long-term average and assist parties in minimising the impact of adverse weather conditions.

It is also important to note that in JCT contracts, exceptionally adverse weather does not fall within the definition of “Relevant Matter”, so contractors will be able to claim additional time to complete the works but will be unable to claim additional money from the employer.

NEC Construction Contracts

NEC Contracts are rather different from JCT Contracts in how adverse weather is determined and what it means. Under the NEC3 and NEC4 Contracts, weather can only be classified as “adverse” if it occurs less than once in ten years within one calendar month. Additionally, NEC contracts do not distinguish between delay events, so the contractor will be able to make a claim for additional time to complete and also money to do so.

However, for this principle to be met, parties are obliged to keep records of weather elements (known as “weather measurements”.) These mainly refer to cumulative rainfall, calculating the number of days of rainfall or snow on the ground and measuring the number of days where the temperature is below 0 degrees Celsius. Parties can also add in their own weather elements, using the Z clauses available.

Here, it will be the project manager who compares the measurements against historic weather data (at local weather stations) to determine whether weather is “adverse”. Nevertheless, if the contractor believes that the Works could be delayed by inclement weather, they must notify the project manager “within eight weeks of becoming aware that the event has happened”.

How should I deal with adverse weather?

If you are a contractor

The key advice here falls into three categories: planning, notices and record-keeping. These could equally be referred to as before, during and after.

Programmes which are running through the depths of winter and the height of summer should make allowances for weather conditions accordingly. Processes which require certain temperature ranges should be timetabled accordingly, along with works requiring a dry period or soft ground through which trenches can be dug. This also affects works such as landscaping.

Your contract is likely to require the contractor to give notices to the employer if adverse weather (or anything else) is likely to cause a delay to project completion. The contractor should ensure that the notices are given in accordance with the timing and details required, to the people specified under the contract.

If adverse weather conditions do strike, records are very important. Photos from site, details of logistical issues (closed roads or difficult travelling conditions) and even video footage can help paint a picture of why the adverse weather caused a delay. The issues caused could include damage to existing works resulting from storms or flooding as well as severe weather preventing work on site or access to site. A weather station on-site will provide accurate data for the site itself, which removes the need for any estimation of wind speeds or amount of rain recorded. An email explaining that “the average site temperature of -2 degrees celcius and the heavy snow from Monday 7th – Thursday 10th prevented the pouring of concrete, setting the entire programme back by four days and requiring additional payments for off-site storage of damp-proofing materials” will be far more likely to accepted by an employer than the assertion that “the cold weather in January delayed us by a week and increased our costs”.

If you are an employer

For employers, if you do not wish to allow contractors the potential for additional time for adverse weather conditions under JCT contracts, or additional time and money under NEC contracts, you can remove this as a Relevant Event/Compensation Event in a schedule of amendments to the contract.

Alternatively, you can specifically define adverse weather conditions and incorporate robust provisions into your contract that deal with what constitutes adverse weather (and what doesn’t). This can take into account different weather elements and the location of the site. If a claim for a Relevant Event or Compensation Event is then raised, you can accurately assess whether these provisions are met.

If you are an employer or contractor and you have any queries regarding adverse weather conditions and how these can be dealt with effectively under a construction contract, please contact a member of our Construction team.

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