The main objectives of this paper are to evaluate the modeling effort associated with generating building information modeling (BIM) at different levels of detail (LoD) and the impact of LoD in a project in supporting mechanical, electrical and plumbing (MEP) design coordination. Results show an increase in total modeling time ranging from doubling the modeling effort to eleven folding it, when going from one LoD to another. When comparing modeling time per object, rates ranged from 0.2 (decreased modeling time) to 1.56 (increased modeling time). Based on the experiments done in MEP design coordination, it was observed that the automatic clash detection process using BIMs, with its consistently higher recall rate, provides a more complete identification of clashes, with the cost of false positives (low precision). This study showed that additional modeling effort can lead to more comprehensive analyses and better decision support during design and construction. (C) 2010 Elsevier B.V. All rights reserved.