Percentage of construction cost seems to be a simple method of compensation. Is it recommended?
It depends. It is simple in concept, but it requires a rigorous determination of what construction cost includes and does not include. The result may be too high or too low given the complexity of the project and the professional services needed to accomplish it. This method may be unfair to the owner (for example, by allowing inflation in the construction marketplace to drive up costs of professional services) and may penalize the architect for investing extra effort to reduce construction cost on behalf of the owner.