Store display_sidebar in static variable

lib/config.php

@@ -34,6 +34,9 @@ add_filter('body_class', 'roots_sidebar_body_class');
  * See lib/sidebar.php for more details
  */
 function roots_display_sidebar() {
+  static $display;
+
+  if (!isset($display)) {
     $sidebar_config = new Roots_Sidebar(
       /**
        * Conditional tag checks (http://codex.wordpress.org/Conditional_Tags)
@@ -57,8 +60,10 @@ function roots_display_sidebar() {
         'template-custom.php'
       )
     );
+    $display = apply_filters('roots/display_sidebar', $sidebar_config->display);
+  }  
 
-  return apply_filters('roots/display_sidebar', $sidebar_config->display);
+  return $display;
 }
 
 /**