The high luminosity operation of the LHC will require an upgrade of the CMS silicon tracker, possibly implementing trigger capabilities. In order to evaluate the possible options and geometries, a standalone software package has been developed (tkLayout) to generate detector layouts, evaluate the effect of inactive material and provide an a priori estimate of the tracking performance. The package can be used to compare the performance of different options, and then to optimize the chosen detector concept; tkLayout is not specific to CMS, thus it can be adapted to design studies for other tracking detectors. The technology of tkLayout is presented, along with some results obtained in the context of the CMS Tracker design studies. Presented at ICATPP 2011: 3th ICATPP Conference on Astroparticle, Particle, Space Physics and Detectors for Physics Applications October 17, 2011 22:15 WSPC Proceedings Trim Size: 9in x 6in como ̇mersi