Tier on Tier Shutter

A two tier interior shutter whose upper and lower louvred panels open and tilt independently, so the top can be open while the bottom stays closed. One panel or a pair hinged to the frame, Where the tiers split, Louvre size and tilt rod style, Frame style, colour and hinge finish

Details

By Huu Khanh Nguyen · Updated November 5, 2026

Parameters

Name	Default	Unit
Width	1000	mm
Height	1800	mm
Louvre Size	63.5	mm
Stile Width	50.8	mm
Top and Bottom Rail Height	76.2	mm
Frame Style	plainL
Frame Depth	46.5	mm
Tilt Rod	standard
Shutter Colour	shutterWhite
Hinge Finish	match
Gap Above and Below Panels	2.5	mm
Gap Between Panels	2	mm
Gap Between Tiers	2.5	mm
Height of Tier Split	900	mm
Panel Arrangement	LR
Left Panels	configuration == 'R' ? 0 : 1
Right Panels	configuration == 'L' ? 0 : 1
Lower Tier Opening	0	°
Upper Tier Opening	0	°
Lower Tier Louvre Tilt	50	°
Upper Tier Louvre Tilt	50	°
Panels	leftPanels + rightPanels
Panel Width	(sizeX - 2 * 38.1 - (panelCount + 1) * panelGap) / panelCount	mm
Panel Height	tierSplit - 38.1 - clearance - tierGap / 2	mm
Lower Louvre Field Top	lowerPanelHeight - railHeight	mm
Upper Louvre Field Bottom	lowerPanelHeight - railHeight	mm
Lower Louvres	Math.max(1, Math.round((lowerLowerTop - railHeight) / (0.9705 * louvreSize - 12.2)))
Upper Louvres	0
Lower Louvre Pitch	(lowerLowerTop - railHeight) / lowerLowerCount	mm
Upper Louvre Pitch	(lowerPanelHeight - railHeight - lowerUpperBottom) / Math.max(1, lowerUpperCount)	mm
Louvre Length	panelWidth - 2 * stileWidth	mm
Panel Height	sizeZ - 38.1 - clearance - tierSplit - tierGap / 2	mm
Lower Louvre Field Top	upperPanelHeight - railHeight	mm
Upper Louvre Field Bottom	upperPanelHeight - railHeight	mm
Lower Louvres	Math.max(1, Math.round((upperLowerTop - railHeight) / (0.9705 * louvreSize - 12.2)))
Upper Louvres	0
Lower Louvre Pitch	(upperLowerTop - railHeight) / upperLowerCount	mm
Upper Louvre Pitch	(upperPanelHeight - railHeight - upperUpperBottom) / Math.max(1, upperUpperCount)	mm