Two sets of shutter                                                                                      panels installed within                                                                              the same frame, one set                                                                      above the other. The top and bottom set open independently and this allows the greatest flexibility with controlling light and privacy. Tier on Tier shutters are generally suited to tall and narrower windows (think of a stable door). The split between tiers is usually in line with the top of a horizontal glazing bar present on the window. This style is very well suited to tall Victorian bay windows.