Estimating duration of projects manual tasks is one of the crucial concepts and problems of their management and control. Methods have been used to achieve this estimation are so difficult, time consumer and basically unreliable. In this paper a new method is introduced based on modular arrangement of predetermined time standards (MODAPTS) plus method which is the well-known method of work measurement. The method is reliable according to reliability of the MODAPTS method. The method is so easy to use, so quick in application, has rapid derivation of objective standards and its analysis are regarding people and their capacities. Finally, an applicability of the method is illustrated by some general manual sample civil works and the results are shown at the end of the paper.