NEC 4 Option A - ECI?

We are tendering a project where the ITT refers to the main contract being awarded as an NEC 4 Option A. In addition, the ITT then mentions the option of an ECI for the successful tenderer. NEC4 only includes X22 in Options C & E. What would the best method be to include an ECI phase with an Option A contract ? Could it be done by a stand alone Professional Services Contract instead ? Would it need to be a separate form of contract ?

Any suggestions, much appreciated.

You might like to search for recently published books on Early Contractor Involvement, as the one published by Emerald Publishing considers these questions in depth.

As for your ITT, there are far too many supplementary questions that flow here! I’m not clear there is a ‘best’ method. You can amend X22, you can use something separate, that can be PSC or ECC. It depends on what you plan to do in Stage 1, and your preferences.