Honesty
Honesty really is the best policy. Just because it is. On moral grounds alone.
In construction, it also makes the most practical sense.
Construction projects are most likely to be successful when the key participants—owner, design team, subcontractors and builder—have healthy relationships. That means parties trust one another. They know that the other parties make decisions and take actions with the best interests of the project in mind. They regard contracts as tools to help organize objectives and responsibilities, not as documents to hide behind. That level of trust means they can focus their effort where it belongs. On the work.