What is a Qualifying Cause of Delay Under an AS 4300?

Clause 35.5 entitles contractors to claim an extension of time under an AS 4300 contract. This clause covers causes of delay and contains two subclauses that outline the types of delay that may warrant an extension of time. These are subclauses (a) ‘events occurring on or before the date of practical completion’ and (b) events that occur at any time before, on, or after the date of practical completion. 

Clause A- Before the Date for Practical Completion 

Clause 35.5(a) allows the contractor to claim an extension of time where they face a delay from any event that occurs on or before the date for practical completion. This delay must be beyond the control of the contractor. Examples of this type of event include inappropriate workplace conditions, and weather. Typically, most events will be covered by this clause as long as they are beyond the contractor’s reasonable control. 

Clause B- Before, On or After the Date for Practical Completion 

This clause provides further examples of qualifying causes of delay. These events go further than subclause A as they can occur after the date for practical completion, however, the scope of these events are narrower. 

Examples of causes: 

• Delay/ disruption caused by principal/ their employees,
• Latent conditions, 
• Variations, 
• Change in law, 
• wrongly estimated quantities of work set out in the contract,
• Delays by public/ statutory authorities (cannot be from the contractor’s fault), and
• Principal’s breach of contract 

Concurrent Delays 

There are limitations to when a contractor will be entitled to claim an extension of time. Where there are two or more events contributing to the delay and at least one event is not mentioned in clause 25.5(a), and (b), the contractor will not be able to obtain an extension of time. This contracts other construction contracts such as the AS 4000 which allows for the apportionment of delays leaving the contractor to remain with their entitlement to make a claim for an extension of time. 

Principal Liability Over Costs 

Some events will warrant the principal to be liable to pay costs under clause 36. This is when the extension of time has been granted for: 

• Delays caused by the actions of the principal, 
• Delays caused by the conduct of the superintendent, 
• Delays caused by the principal’s or superintendent’s employee, consultant or contractor.

The principal will also have to pay costs where delay costs are mandated by another clause in the contract or by the annexure. An example will be clause 12.3 which states that the contractor will be entitled to a valuation where a latent condition caused the delay to the contractor. 

Final Notes 

Qualifying cause of delays under an AS 4300 contract are outlined by clause 35.5. Within this clause, there are two subclauses (a) and (b) which provide two types of events that may entitle a contractor to claim an extension of time. Causes before or on the date for practical completion will most often give rise to the contractor’s claim to extension of time, however, causes occurring after the date of practical completion are narrower and not always successful in claims. 

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