A stairwell fixture only works if it is judged from the floor below, not from directly underneath. Here is how to set the diameter and the drop so it reads correctly from where people actually stand.
A staircase or void is the one place where a chandelier is judged entirely from underneath, from a distance, and in daylight. Those three conditions change the rules, and they are why so many double-height fixtures end up looking undersized despite being physically large.
If you size the fixture as a proportion of the ceiling it hangs from, it will be too small. From the ground floor, a 1.5 m fixture under a 6 m ceiling occupies a tiny fraction of your field of view — it reads as an accessory rather than a feature.
Stand at the most-used viewing position — the bottom of the stairs, the entry to the room — and look up. The fixture should occupy a meaningful share of the void it hangs in. As a working starting point, the finished diameter is usually between one third and one half of the smallest horizontal dimension of the void. Narrow stairwells take a proportionally larger, longer piece; a wide atrium can carry a wider one.
Two constraints fight each other here. Hang it too high and the light never reaches the floor; hang it too low and it intrudes on the space or breaches headroom on the landing.
On any piece that will not fit through the opening in one go, plan for sections from the start. A well-made modular fixture has numbered joints, matched sections and a 1:1 installation drawing — and once assembled, the joints are not visible from the floor below. Modularity is not a downgrade; it is what makes a five-metre fixture installable in a building that was not designed around it.
With those six items, a factory can return a scaled 1:1 drawing that shows you the real proportion before anything is built.
Most first enquiries stall because one number is missing. Here is the short list that lets a factory quote you properly on the first reply — and the two numbers people most often get wrong.
Read the guide ›The sample approval is the single point where you have the most leverage and the least time. A twelve-point check that prevents the expensive arguments later.
Read the guide ›Send dimensions, a drawing or a reference photo. You get a straight answer — including “this will not work” if that is the truth — within one working day.
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