Selecting the right construction contract is one of the most important decisions you will make at the outset of any project. The contract you choose will shape how risk is allocated, how disputes are resolved and how efficiently the project is delivered.
In the UK, the two most widely used standard forms are the JCT (Joint Contracts Tribunal) and NEC (New Engineering Contract) suites. While both are well-established, they take very different approaches to project management and risk allocation.
Understanding these differences is key to ensuring that your contract supports, rather than hinders, your commercial objectives.
Understanding JCT and NEC contracts
JCT and NEC contracts are both designed to provide a structured legal framework for construction projects, but they reflect different philosophies.
JCT contracts are traditionally used across the UK construction industry and are often seen as more familiar. They follow a conventional approach, setting out clear roles, responsibilities and processes for dealing with issues such as delays and variations. NEC contracts, by contrast, are designed to promote collaboration and proactive project management. They adopt a more flexible and forward-looking approach, encouraging parties to work together to identify and manage risks at an early stage.
In practical terms, while both forms are used across the construction sector, NEC contracts are particularly prevalent on engineering and infrastructure projects, whereas JCT contracts remain the more common choice for building projects
Key differences in risk allocation
One of the most important distinctions between JCT and NEC contracts lies in how they allocate risk between the parties.
Under JCT contracts, risk is typically allocated in a more traditional way, with each party responsible for specific aspects of the project. The focus is often on managing issues after they arise, through formal processes such as claims for extensions of time (EoT) arising from a Relevant Event or loss and expense arising from Relevant Matters
NEC contracts take a different approach. They require the parties to proactively manage risk throughout the project, using mechanisms such as early warning notices which is a mandatory requirement. This means that potential problems such as delay in completion or project key dates and increase in price are identified and addressed before they escalate.
From a commercial perspective, this proactive approach can reduce the likelihood of disputes and help keep projects on track. However, it also requires greater engagement and discipline from all parties involved, making the role of a project manager very critical to the success of any NEC contract
Managing delays, changes and costs
Delays, variations and cost control are central to any construction project, and the way these are handled differs significantly between JCT and NEC. Under JCT contracts, delays and changes are generally dealt with through formal claims processes such as EoTs, and variations. This can provide clarity, but it may also lead to disputes if issues are not handled promptly or transparently.
NEC contracts place a stronger emphasis on real-time management. Changes are assessed as they arise, and cost implications are addressed on an ongoing basis through compensation events. This can improve transparency and allow for better financial control throughout the lifespan of the project. However, this approach requires careful administration through the support of the project manager. Without proper management, the flexibility of NEC contracts can create uncertainty rather than clarity.
Selecting the best contract for your project
Choosing between JCT and NEC will depend on the specific nature of your project and your organisation’s priorities.
A JCT contract may be more suitable where:
- the scope of works is clearly defined at the outset
- a traditional, well-understood contract structure is preferred
- the project team has limited experience with NEC processes
An NEC contract may be the better option where:
- the project is complex or likely to evolve over time
- collaboration and communication between parties is critical
- proactive risk management is a key priority
There is no universal “right” choice. The key is to ensure that the contract aligns with how your project will be managed in practice. NEC should be used only where the parties understand and embrace its philosophy and are able to manage it proactively, as effective contract administration is central to its success.
Once the parties have decided whether to use JCT or NEC, they must then select the most appropriate contract within that suite. Both offer a range of options designed for different project types, procurement routes and levels of complexity. In the JCT suite, the most commonly used forms include the Design and Build Contract, Standard Building Contract, Intermediate Building Contract and Minor Works Contract, each catering for different project requirements and risk allocations. Taking the time to choose the right form is important, as the success of a project often depends as much on selecting the appropriate contract within the suite as it does on choosing between JCT and NEC in the first place.
Avoiding common contractual pitfalls
Regardless of which contract you choose, there are common pitfalls that businesses should be aware of. A frequent issue is failing to fully understand the obligations imposed by the contract. Both JCT and NEC require strict compliance with their procedures. Missing a deadline or failing to follow the correct process can have significant commercial consequences.
Another common risk is relying too heavily on standard forms without tailoring them to your project. While JCT and NEC contracts provide a strong starting point, they often require amendment to reflect the specific risks and objectives of the project.
The JCT standard form is often amended through a schedule of amendment that sets out provisions the parties wish to include, modify or delete. For an overview of the amendments most frequently made to JCT contracts, see our Article.
In contrast, bespoke amendments to the NEC contract are typically done using Z clauses.
Businesses should also ensure that:
- key commercial terms are clearly defined
- roles and responsibilities are properly understood
- project teams are trained in the chosen contract form
- appropriate records are kept throughout the project
Taking these steps can help minimise disputes and ensure that the contract operates as intended.
Supporting your project with the right legal advice
Choosing between JCT and NEC is not simply a legal decision. It is a commercial one that can affect the success of your project from the outset. Our construction team works with developers, contractors and businesses to ensure that construction contracts are aligned with their wider objectives. We provide clear, practical advice on selecting and negotiating the right contract, managing risk and avoiding costly disputes.
Whether you are starting a new project or reviewing your existing contractual arrangements, early advice can help you make informed decisions and protect your position. By putting the right structure in place from the beginning, you can reduce risk, improve project delivery and achieve better commercial outcomes.
If you are considering your options between JCT and NEC, please contact us to discuss your project and help you identify the most suitable approach.
