While we have all heard the average of 10% changes on construction projects, it is interesting to look at an industry study for validation.
This study by HBRC categorized the range of contract changes and the percent of projects within that range. The average is 10% and none of the projects had 0% changes.
Engaging key contractors to work on the project earlier will lower the amount of changes related to design conflicts while protecting the aesthetics of the design.
Another interesting part of the study was that 43% of respondents DID NOT have a consistent process for managing changes.
A rigorous change management process starts at the earliest stages of design development with rigorous weekly reviews.
During construction, the definition of a change should be broadened beyond what may become a cost issue for the project owner and also managed through a rigorous weekly process such the Last Planner System.