A staircase needs light that shows every tread edge, switched from both top and bottom (two-way switching — standard in new work), with no bare bulb in the descending eyeline. Add a very low, separately-switched or sensor-driven layer for the 3am crossing, run everything at 2700K, and give the landing's turn one good wall light — it is the most safety-critical lit spot in the house.
Stairs are where domestic lighting stops being aesthetic. Falls on stairs are among the most common home accidents in the UK, and the lighting factor is always the same: tread edges you cannot see, or a glare source exactly where a descending eye looks. The good news is that stair lighting is a solved problem with about three moving parts.
What the regulations actually say
Building Regulations expect stairways to be adequately lit, and in new work the electrical convention is two-way switching — the stair light operable from both floors — which is the part that matters day to day. Nothing compels an existing home to retrofit, but the test is practical, not legal: if reaching the switch requires crossing the stairs in the dark, the installation has failed, whatever its paperwork says. An electrician can add two-way switching to an existing circuit in a morning; wireless switch kits do it without chasing walls.
Light the edges, spare the eyes
A descending person looks down the flight at roughly 30 degrees — so any unshielded fitting at the bottom of the stairs sits precisely in their gaze. The two placements that work: a fitting above the middle of the flight (ceiling, or a wall light at 1.7–1.8m) throwing light along the treads, or several low-level fittings grazing light across the steps so each nosing casts a small shadow and the geometry becomes legible. Grazing light is why hotel stairs feel safe: relief, not brightness, is what feet read.
Cortona on the stair wall
Slim enough for the narrowest UK staircase, and its faceted glass scatters light along the flight rather than dumping it in one pool — mounted at 1.7m, mid-flight.
The landing: the turn is the point
Most UK stairs turn at a half-landing, and that turn — where the geometry changes underfoot — is where light matters most. One warm wall light there serves both flights at once and, dimmed low, becomes the upstairs' evening pilot light. The landing is also where the hallway principles apply upstairs: light the walls, give the corridor's end a glow, match the temperature of the rooms it serves.
The 3am layer
Nobody wants the main stair light at 3am — so give the route a second, very low layer: a dim wall light on its own switch, a low-output sensor fitting, or a plaster-in downlight dimmed to a few percent. Motion-sensing versions solve it for children and older relatives entirely; the light appears at ankle-brightness before the first step and nobody's night vision is destroyed. It is the cheapest safety feature in the house.
