In the context of construction contracts and projects, a consultant is usually a company or individual with specialist knowledge and experience in a particular field who provides advice or consultancy services to one of the parties to a construction contract, most commonly the developer.
The role of the consultant can vary depending on the specifics of the project and the needs of the client, but generally includes:

• Technical advice: The consultant can provide advice related to design, execution, construction supervision, quality of workmanship, environmental engineering, etc.
• Research and analysis: The consultant may carry out studies and analyses to assess the efficiency, feasibility or regulatory compliance of a project.
• Design support: The consultant may be involved in the development of design documentation, technical specifications, cost estimates, etc.
• Supervision and control: In some cases, the consultant may act as the developer's supervisor, exercising control over construction progress and ensuring compliance with design requirements.
• Expert reports and opinions: The consultant may prepare technical expert reports, legal opinions or reports on specific aspects of the project.

It is important to note that the role of the consultant can be varied and tailored to the specific needs of the project and the client's expectations. Consultants are often highly specialised in their field and are a valuable resource in the process of delivering complex construction and engineering projects.