Tier-on-Tier Shutters for Northern Irish Period Sash Windows

If your Northern Irish home has original Victorian or Edwardian sash windows, you've inherited one of the great British architectural details — a window designed to open top and bottom for airflow, light and privacy. Fit a single full-height shutter over it and you've lost the whole point. Tier-on-tier shutters keep it intact.

What tier-on-tier actually is

The window is split into two panels — upper and lower — each independently hinged, each independently tiltable, each opening on its own hinges. You can leave the top half open for morning light and close the bottom for street-level privacy. Or reverse it at night. Or open both. Or close both. On a period sash it mirrors exactly what the original sash was doing.

Where it wins

• Belfast Victorian terraces — the sash window IS the front-of-house detail. Tier-on-tier preserves the geometry.
• Georgian townhouses in Armagh, Portadown and Lisburn — often 6-over-6 sashes that suit the split perfectly.
• Period bedrooms with the window over the bed — you can close the lower half for privacy without darkening the room.
• First-floor front rooms on any older NI home where passers-by are eye-level.

The mid-rail question

The horizontal mid-rail (where the upper and lower panels meet) should always line up with the meeting rail of the original sash. We measure this precisely on survey so the shutter reads as an extension of the window itself, not an addition to it.

Louvre size

76 mm for classic period elegance. 63 mm if you want it to feel more Victorian-cottage. Never 89 mm — it looks too contemporary in a heritage sash context.

A single full-height shutter on a period sash is a compromise. Tier-on-tier is a translation.

One downside to know

Tier-on-tier is roughly 15-20% more expensive than an equivalent full-height because there are more panels and more hardware. On a period-correct restoration it's worth every penny. On a modern new-build it usually isn't — full-height is the right call there.