The Construction Clients' Group says it will update its clients' charter by October.
Constructing Excellence and the CCG will soon tender for an independent consultant to review the current Charter and examine its current and potential users.
The charter, which is run by management firm Achilles Information, dates from 2001.
A review was ordered last year after CCG left the British Property Federation to become part of Constructing Excellence.
Chris Morley, CCG's chief executive, said the chosen consultant would carry out "a quantitative and qualitative analysis of current perceptions of the charter and its use".
Its recommendations will be implemented by this October.
The original deadline to complete the first analysis review was in March. Morley said this would be missed as a result of the group's relocation to Constructing Excellence's offices.
He added: "Achilles will of course be fully involved in the review and are being supportive of the review.
"Being a charter client is one way to demonstrate that you are a good client to work with and that you recognise the responsibility of a client of the construction industry."
More than 400 public and private-sector clients, including airport operator BAA and the Highways Agency, have signed up to the charter since its launch.