THE FLOOR EDGE SLOT
The floor edge slot is an integrated lighting detail that
has been in widespread use since the 1980s. Before
that, light had always come from a ceiling or wall light.
Unlike the ceiling slot, the technique is almost always
decorative – light from below can be unflattering.
Two notable retail schemes that incorporate the
technique are the Jigsaw store in New Bond Street,
London and House of Fraser in Oxford Street. At
Jigsaw, Isometrix deployed edge slots down the side
of a long stairwell, and in the basement at House of
Fraser, Mindseye used the technique to set apart a
funky young fashion area from the rest of the space.
This is not to suggest that retail has monopolised the
technique – it is used in some residential schemes – but
‘it has to be a pretty swanky pad, obviously’, says James.
‘You tend to find it where there’s very clean architecture,
a minimalist approach.’
The technique is about ‘announcing the surface and
separating it from the floor’, says James, but the extent
to which the wall is washed with light depends on the
sources used and how they are deployed. In the Jigsaw
scheme a mix of MR16s and T5 lamps were used but
more commonly now we would use a diffuse linear
effect with an LED wall grazer.
A practical minimum for the slot width is about
100mm, although James suggests 150mm could
make access and maintenance easier. LEDs allow this
width to be narrower still. The depth of the slot varies
depending on the source and any reflectors used to
push the light further up the wall.
Glass may be placed over the slot so the floor can
still be cleaned and objects do not fall into the void.
Alternatively, a vertical cover tucked under the
overhang can preserve the appearance of a slot, but
make it easier to ‘pull the sweet wrappers out’.
Before a designer can even consider this technique
there must be a slot at the edge of the floor. This
assumes that the floor is raised, or that a channel was
incorporated into the floor during casting.
Stairs, however, are easier to edge light because they are
a separate element from the walls or the floor.
James also warns that the technique is not without
its pitfalls. ‘This stuff has to be IP-rated,’ he says. ‘You
wouldn’t want to spec a standard bare batten down
there. Someone could put their fingers or a mop in.’
He also cautions that the light sources must be
overlapped or abutted correctly, and that LEDs tend to
be directional. ‘You have to be careful about getting a
series of intense splodges of light along the wall.’
‘Again, if you’re planning a detail like this,’ he suggests,
‘do yourself a mock-up first.’
Above: Paul Nulty Lighting
Design used a floor edge slot
in its award-winning scheme
for Matchesfashion.com in
Opposite: A standard floor edge
slot, but horizontal glazing may
be needed to prevent ingress of
objects – or a vertical barrier can
be fitted in front of the lamps