Drupal 7 module - page layout changes
Module:


The Empty Page module is a simple empty page solution. It provides an interface that assists in managing "empty" menu callbacks, mostly used for pages that only consist of blocks.
The Panels module allows a site administrator to create customized layouts for multiple uses. 
Context allows you to manage contextual conditions and reactions for different portions of your site. For each context, you can choose what blocks to show.


Theming:


Template suggestions are alternate templates based on existing .tpl.php files. You can write in preprocess_page , where put condition and if true, assign page template to page--empty.tpl.php - here you should remove all regions printing except content - so you will get empty page.